tag:blogger.com,1999:blog-79869076408485147022024-03-13T23:14:08.981-07:00Joseph R. FarahJoseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.comBlogger48125tag:blogger.com,1999:blog-7986907640848514702.post-35140362672453132222024-02-27T21:46:00.000-08:002024-02-27T21:46:09.055-08:00Thermal vacuum testing for the Europa Clipper<p>NASA (via <a href="https://www.youtube.com/watch?v=yKDA6smS9_k">YouTube</a>):</p><blockquote><p>We'll be back soon. The spacecraft is currently undergoing vacuum testing.</p></blockquote><p>I was a huge fan of the livestream for building the Perseverance rover--I'm glad they've got another one running for Clipper. It's fun to check in on the progress of the build and try to guess what they're working on at any given moment. </p><p><a href="https://astrobiology.com/2024/02/swri-scientists-lead-two-europa-investigation-teams.html">Astrobiology.com</a>:</p><p></p><blockquote><p>Scheduled to launch in October 2024 and arrive in the Jupiter system in 2030, NASA’s Europa Clipper mission will place a spacecraft in orbit around Jupiter to perform a detailed investigation of Europa.</p><p>This will maximize the scientific return from the lifetime of Europa Clipper, which is investigating the “habitability” of Europa. Habitability is a measure of whether Europa could support life and includes the presence of essential ingredients like liquid water, chemical building blocks and an energy source.</p><p>“Europa is considered one of the most likely sites in our solar system to potentially find life,” said SwRI Lead Scientist Dr. Kelly Miller.</p></blockquote><p></p><p><a href="https://phys.org/news/2024-02-countdown-nasa-jupiter-mission-jpl.html">Phys.org</a>:</p><p></p><blockquote><p>Today is a big day for the Europa Clipper team. They'll be testing the craft's thermal pumping system, the last major addition to the spacecraft's vault, a thick-walled aluminum alloy box that holds the spacecraft's "brain": its electronics and computers.</p><p>"The thermal pump is the heart of the spacecraft," pumping fluid through
tubing to control the craft's temperature, Barajas said. The daylong
effort is hazardous because of the high pressure used to test the system
with helium, a nonflammable gas.</p><p>"Planetary protection has evolved," Barajas said of the strict work requirements he has to follow every day. "No one wants to be the person responsible when extra-terrestrial life is finally found and it turns out to be something we brought there from earth."</p><p>"I think that's where the stress comes from, right? That we feel the pressure and the burden of building this vehicle that has been the life's work of some and years of work for many others."</p></blockquote><p>I'll continue updating this thread with news of the Europa Clipper development. <br /></p><blockquote><p> </p></blockquote><p><br /></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-66113195099679573252024-02-23T21:02:00.000-08:002024-02-23T21:50:27.049-08:00Second update to: Evidence of near-ambient superconductivity in a N-doped lutetium hydride <p>I've been posting occasional updates as I've followed this and other superconductor stories with great interest. This one took an interesting turn with a series of retractions from <i>Nature</i>.</p><p><i><a href="https://www.nature.com/articles/s41586-020-2801-z">Nature</a>: </i></p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">RETRACTED ARTICLE: Room-temperature superconductivity in a carbonaceous sulfur hydride</p><p style="text-align: left;">The editors of Nature have been alerted to concerns regarding the manner in which the data in this paper have been processed and interpreted. Nature is working with the authors to investigate these concerns and establish what (if any) impact they will have on the paper’s results and conclusions. In the meantime, readers are advised to use caution when using results reported therein. </p></blockquote><p style="text-align: left;"></p><p style="text-align: left;">This is their second retracted paper.<br /></p><p><i><a href="https://www.nature.com/articles/d41586-023-03398-4">Nature News</a>:</i></p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Nature has retracted a controversial paper claiming the discovery of a superconductor — a material that carries electrical currents with zero resistance — capable of operating at room temperature and relatively low pressure.</p><p style="text-align: left;"> “They have expressed the view as researchers who contributed to the
work that the published paper does not accurately reflect the provenance
of the investigated materials, the experimental measurements undertaken
and the data-processing protocols applied,” [the retraction report] says, adding that these
co-authors “have concluded that these issues undermine the integrity of
the published paper”.</p><p style="text-align: left;">“It is at this point hardly surprising that the team of Dias and Salamat has a third high-profile paper being retracted,” says Paul Canfield, a physicist at Iowa State University in Ames and at Ames National Laboratory. Many physicists had seen the Nature retraction as inevitable after the other two, and especially since The Wall Street Journal and Science reported in September that 8 of the 11 authors of the paper — including Salamat — had requested it in a letter to the journal.</p><p style="text-align: left;">One lab says it has partially reproduced Dias and Salamat’s results using a sample provided by the Rochester team. But many others, which tried creating their own samples and running tests, could not. And in the meantime, other causes for concern have arisen. An investigation launched by Physical Review Letters before it retracted its paper by Dias and Salamat found “apparent data fabrication”.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><a href="https://www.science.org/content/article/another-retraction-looms-embattled-physicist-behind-blockbuster-superconductivity">Science.org</a>:</p><p style="text-align: left;"><i> </i></p><blockquote><p style="text-align: left;">Facing a mutiny by his co-authors, Ranga Dias, the University of Rochester (U of R) physicist embroiled in controversy over his superconductivity research and allegations of scientific misconduct, is set to have a third paper retracted.</p><p style="text-align: left;">If the paper is retracted, it will follow retractions of two other superconducting claims from Dias’s teams: one last month from Physical Review Letters (PRL), and one in September 2022 of a different Nature paper.</p><p style="text-align: left;">In a 14 September email to the co-authors, Nature Senior Editor Tobias Rödel says a postpublication review revealed issues that are “mostly unaddressed.” Rödel added, “We are in absolute agreement with your request that the paper be retracted.”</p><p style="text-align: left;">Questions about the March paper’s results appeared online immediately after its publication. On 2 May, two researchers submitted an anonymous critique of the paper to Nature. These researchers disclosed their identities to Science: They are James Hamlin, a high-pressure experimentalist at the University of Florida, and Brad Ramshaw, an expert in superconductivity at Cornell University.</p><p style="text-align: left;">In their letter to Nature the co-authors allege they had raised concerns about the study prior to publication, but that Dias dismissed them. </p><p style="text-align: left;">After seeing the postpublication review, the co-authors used their access to the raw data to corroborate Hamlin and Ramshaw’s concerns about the zero-resistance measurement. </p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><a href="https://www.nytimes.com/2023/08/15/science/retraction-ranga-dias-rochester.html">New York Times</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">A prominent physics journal on Tuesday retracted a materials science paper that has garnered scrutiny. </p><p style="text-align: left;">The retracted paper did not involve superconductivity, but it added to accusations against Dr. Dias of research misconduct, including the fabrication and falsification of data. </p><p style="text-align: left;">Nine of the 10 authors of the paper, which was published in Physical Review Letters, agreed to the retraction. Dr. Dias was the lone holdout, and he has maintained that the paper accurately portrays the research findings. However, he said on Tuesday that his collaborators, working in the laboratory of Ashkan Salamat, a professor of physics at the University of Nevada, Las Vegas, introduced errors when producing charts of the data using Adobe Illustrator, software not typically used to make scientific charts.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;">This took me pretty massively by surprise. I can only speak from my own personal experience, but nobody--I mean<i> nobody</i>--makes charts by hand anymore. We've had programmatic tools to ensure precision for literally decades. Most plots these days are done using scripts that access plotting libraries; for example, I make my plots in Python using <a href="https://matplotlib.org/">matplotlib</a>. I just can't understand what part of the process one would use Adobe Illustrator of all things for--I wish Dr. Dias had elaborated on this more. The problems identified were found in the background subtraction procedure and potentially claims of duplicated data; without commenting on the truth of these allegations, how could one "accidentally" do these things or something similar in Adobe Illustrator of all things? And why would this affect the raw data files that were shared with the investigators and coauthors, which ultimately were found to be flawed as well? </p><p style="text-align: left;"><a href="https://www.nature.com/articles/d41586-023-02401-2">Nature News</a>:<br /></p><p style="text-align: left;"></p><blockquote>As part of the investigation, co-author Ashkan Salamat, a physicist at
the University of Nevada, Las Vegas, and a long-time collaborator of
Dias, supplied what he claimed was raw data used to create figures in
the <i>PRL</i> paper. But all four investigators found that the data Salamat provided did not match the figures in the paper.</blockquote><p></p><p style="text-align: left;">Ignoring everything else, the raw data didn't match the figures. But Dr. Dias necessarily needs the figures to be correct if his superconductor is legitimate--the figures showed the proof. </p><p style="text-align: left;"><a href="https://www.sciencenews.org/article/room-temperature-superconductor-retracted-ranga-dias">Science News</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">A stunning claim of a room-temperature superconductor that grabbed headlines has fizzled. The paper was retracted November 7 from the journal Nature, making for a trio of high-profile retractions for physicist Ranga Dias of the University of Rochester.</p><p style="text-align: left;">The retraction is no surprise to the scientific community, many of whom had expressed hefty skepticism about Dias’ work, following the earlier retractions and many other researchers’ failures to reproduce Dias’ results. </p><p style="text-align: left;">Compared to the previous retractions, “this is much more worrying,” Boeri says. “This is not just somebody who is doing some honest mistakes.”</p></blockquote><p style="text-align: left;"><br /></p><p style="text-align: left;">Ranga Dias (via <a href="https://twitter.com/rdias495/status/1748168980353691998">Twitter</a>):</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Meissner effect on N- doped Lutetium Hydride! </p><p style="text-align: left;">[mic drop gif] <br /></p><p style="text-align: left;">The Meissner effect is considered the definitive proof of superconductivity!</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;">I look forward to the submission of that result. At the end of the day, everyone only benefits if Dr. Dias is correct and room-temperature superconductivity is achieved. </p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"><br /></p><p style="text-align: left;">Previously on this blog:</p><ul style="text-align: left;"><li style="text-align: left;"><a href="https://www.jrfarah.blog/2023/03/evidence-of-near-ambient.html">Evidence of near-ambient superconductivity in a N-doped lutetium hydride</a></li><li style="text-align: left;"><a href="https://www.jrfarah.blog/2023/05/update-to-evidence-of-near-ambient.html">Update to: Evidence of near-ambient superconductivity in a N-doped lutetium hydride </a><br /></li></ul>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-44386876769212295572024-02-23T20:37:00.000-08:002024-02-27T21:47:54.867-08:00Neutron star discovered in center of Supernova 1987A<p><a href="https://www.science.org/doi/10.1126/science.adj5796"><i>Science</i></a>:</p><p style="margin-left: 40px; text-align: left;">Editor summary: The nearby supernova SN 1987A was visible to the naked eye, and its
evolution has been observed over the ensuing decades. The explosion is
thought to have produced a neutron star or black hole, but none has been
directly detected. Fransson <i>et al</i>. observed a remnant of SN
1987A using near- and mid-infrared integral field spectroscopy. They
identified emission lines of ionized argon that appear only near the
center of the remnant. Photoionization models show that the line ratios
and velocities can be explained by ionizing radiation from a neutron
star illuminating gas from the inner parts of the exploded star</p><p><a href="https://www.nature.com/articles/d41586-024-00528-4">Nature News</a>: </p><p style="margin-left: 40px; text-align: left;">Astronomers used the [JWST] to finally spot signs of an ultradense ‘neutron star’ lurking in the explosion’s core in a galaxy that orbits the Milky Way. Light from the explosion reached Earth 37 years ago this week, in a supernova that revolutionized modern astrophysics by providing an up-close look at how stars die.</p><p style="margin-left: 40px; text-align: left;">JWST did not observe the neutron star directly, because it remains obscured behind a veil of dust from the explosion. But the telescope detected light coming from argon and sulfur atoms that had been ionized, or electrically charged, by radiation blazing from the long-sought neutron star.</p><p style="margin-left: 40px; text-align: left;">Over the years, astronomers watched as rings of gas and dust expanded outwards from the site of the explosion, usually growing dimmer but sometimes brightening when various ejected materials collided. </p><p style="margin-left: 40px; text-align: left;">One outcome of such a supernova is to leave behind a black hole. But early observations of SN 1987A, such as the wave of neutrinos, suggested that it should have given rise to a neutron star, which can be just 20 kilometres across but is so dense that a teaspoonful weighs millions of tonnes.</p><p><a href="https://www.space.com/james-webb-space-telescope-supernova-wreckage-neutron-star">Space.com</a>:</p><p style="margin-left: 40px; text-align: left;">Using the James Webb Space Telescope (JWST), astronomers have ended a nearly decade-long game of celestial hide-and-seek after they discovered a neutron star in the wreckage of a stellar explosion.</p><p style="margin-left: 40px; text-align: left;">"For a long time, we've been searching for evidence for a neutron star in the gas and dust of Supernova 1987A," Mike Barlow, an emeritus professor of physics and astronomy and part of the team behind this discovery, told Space.com. "Finally, we have the evidence that we've been seeking."</p><p style="margin-left: 40px; text-align: left;">Barlow suggested that researchers may be able to distinguish between a naked neutron star and one clothed by a pulsar-wind nebula by making further infrared observations of the heart of Supernova 1987A with the JWST's NIRSpec instrument. <br /><br />"We have a program which is gathering data now, which will be getting data with 3 or 4 times the resolution in the near-infrared," he concluded. "So by obtaining these new data, we may be able to distinguish the 2 models that have been proposed to explain the emission powered by a neutron star.</p><p style="text-align: left;"> </p><p style="text-align: left;">On the Astraveo podcast:</p><ul style="text-align: left;"><li style="text-align: left;"><a href="https://www.youtube.com/watch?v=4xbRXXSWIag">Supernova 1987A Mystery SOLVED! and more! | Astraveo Coast-to-Coast (Feb 25, 2024) </a><br /></li><li style="text-align: left;"><a href="https://www.youtube.com/watch?v=2SzOVAO9C9o">"No Body, No Crime": Supernova Remains Finally Revealed! (Astraveo Coast-to-Coast Highlight) </a><br /></li></ul>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-20897900481646736942024-02-23T20:30:00.000-08:002024-02-27T21:49:12.556-08:00Astronomers spot new tiny moons around Neptune and Uranus <p><a href="https://carnegiescience.edu/new-moons-uranus-and-neptune-announced">Carnegie Science</a>: </p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">The Solar System has some new lunar members—the first new moon of Uranus discovered in more than 20 years, and likely the smallest, as well as two new moons of Neptune, one of which is the faintest moon ever discovered by ground-based telescopes. <br /></p><p style="text-align: left;">“The three newly discovered moons are the faintest ever found around these two ice giant planets using ground-based telescopes,” explained Carnegie astronomer Scott S. Sheppard. “It took special image processing to reveal such faint objects.” </p><p style="text-align: left;">Discovering all three of the new moons required taking dozens of five-minute exposures over three- or four-hour periods on a series of nights. These exposures were shifted by the apparent motion of each respective planet and added together to create one very deep image. Using this time intensive observing technique on some of the largest telescopes in the world allowed the survey images to go deeper than any previous observations near Uranus and Neptune. <br /></p><p style="text-align: left;">Follow-up observations on the Magellan telescopes in October of 2021 and again in 2022 and November 2023 confirmed the brighter Neptunian moon as orbiting Neptune.</p></blockquote><p><a href="https://www.nbcnews.com/science/space/astronomers-spot-new-tiny-moons-neptune-uranus-rcna140285">NBC</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Astronomers have found three previously unknown moons in our solar system — two additional moons circling Neptune and one around Uranus.</p><p style="text-align: left;">The latest tally puts Neptune at 16 known moons and Uranus at 28.</p><p style="text-align: left;">One of Neptune’s new moons has the longest known orbital journey yet. It takes around 27 years for the small outer moon to complete one lap around Neptune.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><a href="https://www.space.com/new-moons-discovered-uranus-neptune">Space.com</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Uranus' new moon, the first detected around the ice giant in over two decades and possibly the smallest of its ilk, is just 5 miles (8 kilometers) wide; it takes 680 days to complete one orbit around Uranus. In comparison, one Mars' moons named Deimos, considered to be among the tiniest known moons in our solar system, is 8 miles (13 km) wide. </p><p style="text-align: left;">The discovery was made using observatories in Hawaii and Chile by Scott Sheppard, a staff scientist at Carnegie Science, in collaboration with Marina Brozovic and Bob Jacobson of NASA's Jet Propulsion Laboratory (JPL), David Tholen of the University of Hawaii, Chad Trujillo of Northern Arizona University and Patryk Sofia Lykawa of Kindai University.</p></blockquote><p style="text-align: left;"><br /></p><p style="text-align: left;">One of the discovery images shows how insanely faint the moon is compared to Uranus itself (already a very dim object from Earth):</p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><img alt="a black and white, blurry image with lots of white streaks. There is a white blob in the center-right. To the very left of thto which a yellow arrow is pointing." class="block-image-ads hero-image" data-original-mos="https://cdn.mos.cms.futurecdn.net/nUYVwWiYkdiLD6UxTmHZWS.jpg" data-pin-media="https://cdn.mos.cms.futurecdn.net/nUYVwWiYkdiLD6UxTmHZWS.jpg" height="225" src="https://cdn.mos.cms.futurecdn.net/nUYVwWiYkdiLD6UxTmHZWS-320-80.jpg" style="margin-left: auto; margin-right: auto;" width="400" /></td></tr><tr><td class="tr-caption" style="text-align: center;"><i><span class="caption-text">The discovery image of the new Uranian moon
S/2023 U1 using the Magellan telescope on November 4, 2023. Uranus is
just off the field of view in the upper left, as seen by the increased
scattered light. S/2023 U1 is the faint point of light in the center of
the image.</span>
<span class="credit" itemprop="copyrightHolder">(Image credit: Scott Sheppard)</span></i></td></tr></tbody></table><p style="text-align: left;"><br /></p><p style="text-align: left;">On the Astraveo podcast:</p><ul style="text-align: left;"><li style="text-align: left;"><a href="https://www.youtube.com/watch?v=4xbRXXSWIag">Supernova 1987A Mystery SOLVED! and more! | Astraveo Coast-to-Coast (Feb 25, 2024)</a></li><li style="text-align: left;"><a href=" https://www.youtube.com/watch?v=4INy62TnoeM">New Moons Discovered around Uranus and Neptune (Astraveo Coast-to-Coast Highlight)</a> <br /></li></ul>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-5923706050205684552024-01-04T09:13:00.000-08:002024-02-23T21:49:00.726-08:00Coronal mass ejection from colossal New Year's Eve solar flare will strike Earth today<p><a href="https://www.space.com/sun-solar-flare-new-years-eve-coronal-mass-eruption">Space.com</a>:</p><p style="text-align: left;"></p><blockquote>The coronal mass ejection CME was hurled into space by an X-class solar flare that burst from the surface of the sun at 4:55 p.m. EST (2155 GMT) on Sunday (Dec. 31). It is the most powerful flare that has happened on the sun during the current solar cycle, solar cycle 25, which began in Dec. 2019. In fact, the flare that ended 2023 with a bang is the largest that has been observed since Sept. 10, 2017, according to the Space Weather Prediction Center of the National Oceanic And Atmospheric Administration (NOAA).</blockquote><p></p><p>I'm always amused by these comparisons articles like to make. "Largest that has been observed since 2017". We're approaching solar maximum so the flares will be the largest in the cycle. The solar cycle is ~11 years so the last maximum was in the early 2010s, and the last minimum was in the late 2010s. "This solar flare at near maximum was bigger than the ones at the minimum" has substantially less punch.</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Storms like this have the capability to cause weak fluctuations in power grids and could have minor impacts on satellite operations. In addition to this, G1 geomagnetic storms can give rise to striking auroras, beautiful light shows seen over Earth, usually at higher latitudes. </p><p style="text-align: left;">In 2003, during the last solar maximum — the peak of the sun's activity during the solar cycle 24 — an X45 flare was seen erupting from the sun, the most powerful solar flare ever measured. </p><p style="text-align: left;">A powerful X-class flare like the one seen on New Year's Eve has the potential for long-lasting radiation storms, which can damage satellites, including GPS, and affect aircraft flying near the poles of Earth, even giving passengers on these flights small radiation doses. X flares also have the potential to cause worldwide blackouts, if conditions were just right.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><a href="https://thehill.com/homenews/nexstar_media_wire/4384088-strongest-solar-flare-since-2017-detected-heres-what-to-know/">The Hill</a>:</p><p style="text-align: left;"></p><blockquote>In an update Sunday evening, NOAA’s Space Weather Prediction Center (SWPC) released an image of the flare, which appeared as a large, glowing spot on the sun. You can see that image below. </blockquote><p></p><p style="text-align: center;"><img alt="" class="wp-image-4384161" height="356" src="https://thehill.com/wp-content/uploads/sites/2/2024/01/31DecXflare_0-e1704139628312.jpg?w=399" width="390" /><br /></p><p style="text-align: center;"><i>Image reproduced from thehill.com. Original caption: </i>An X5 solar flare detected by NOAA’s Space Weather Prediction Center on December 31, 2023. (NOAA SWPC; cropped)</p><p style="text-align: left;"></p><blockquote>At an X5, Sunday’s flare was much smaller than the flare recorded in 2003. It was, however, the strongest since September 2017, when an X8.2 flare was detected, according to the SWPC. This flare also supersedes an X2.8 solar flare reported in the same region of the sun on December 14. At the time, the SWPC reported that flare was “likely one of the largest solar radio events ever recorded.”</blockquote><p></p><p style="text-align: left;">Possible effects:</p><p style="text-align: left;"></p><blockquote>The SWPC said those using high-frequency radio signals (like emergency managers) may notice a “temporary degradation or complete loss of signal on much of the sunlit side of Earth” as a result of Sunday’s solar flare.</blockquote><p></p><p style="text-align: left;"><br /></p><p style="text-align: left;">Previously on this blog:</p><ul style="text-align: left;"><li style="text-align: left;"><a href="https://www.jrfarah.blog/2023/11/detection-of-long-lasting-aurora-like.html">Detection of long-lasting aurora-like radio emission above a sunspot</a> </li><li style="text-align: left;"><a href="https://www.jrfarah.blog/2023/04/global-geomagnetic-perturbation.html">Global Geomagnetic Perturbation Forecasting Using Deep Learning</a> </li><li style="text-align: left;"><a href="https://www.jrfarah.blog/2023/02/swpc-reports-x-class-solar-flare.html">SWPC Reports X-Class Solar Flare</a> <br /></li></ul><p style="text-align: left;"> </p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-76325894909465744702024-01-03T16:58:00.000-08:002024-02-23T21:49:18.228-08:00New ultra-short period binary discovered<p><a href="https://arxiv.org/abs/2312.13612">arXiv</a>: </p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Binary evolution theory predicts that the second common envelope (CE)
ejection can produce low-mass (0.32-0.36 Msun) subdwarf B (sdB) stars
inside ultrashort-orbital-period binary systems, as their helium cores
are ignited under nondegenerate conditions.</p><p style="text-align: left;">Here we report the discovery of a 20.5-minute-orbital-period ellipsoidal
binary, TMTS J052610.43+593445.1, in which the visible star is being
tidally deformed by an invisible carbon-oxygen white dwarf (WD)
companion. </p></blockquote><p><a href="https://phys.org/news/2024-01-ultra-short-period-binary.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter">phys.org</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">The orbital periods of such detached sdB binary systems can be as short as 20 minutes. However, to date only four binaries of this type with orbital periods below one hour have been found.</p><p style="text-align: left;">Now, a team of astronomers led by Jie Lin of the Tsinghua University in Beijing, China, reports the detection of a new sdB binary with an extremely short orbital period...they discovered a dozen such objects, and one of them, which received designation TMTS J052610.43+593445.1 (or J0526 for short) turned out to be an sdB binary with an orbital period of approximately 20.5 minutes.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><a href="https://bnnbreaking.com/tech/science-tech/new-binary-star-system-discovered-a-key-to-binary-evolution/">BNN Breaking</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">The white dwarf, although ten times smaller than the sun, has a mass of 0.735 solar masses and an effective temperature of 25,400 K. This binary system presents astronomers with a unique opportunity to study the physics and evolution of stars under extreme conditions.</p><p style="text-align: left;">In about 1.5 million years, the subdwarf will begin transferring mass to the white dwarf at an even shorter orbital period, leading to the formation of an AM CVn star through the helium-star channel. This process is pivotal for understanding binary evolution from the second common envelope ejection to the formation of AM CVn stars. The discovery of TMTS J052610.43+593445.1 could play a significant role in investigating these binary evolution paths.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><span> </span></p><p style="text-align: left;"><span>Previously on this blog:</span></p><ul style="text-align: left;"><li style="text-align: left;"><span> <a href="https://www.jrfarah.blog/2023/09/mysterious-black-hole-twins-may-fuel.html">Mysterious Black Hole Twins May Fuel The Brightest Galaxies in Space</a></span></li><li style="text-align: left;"><span><a href=" A radio-detected Type Ia supernova with helium-rich circumstellar material ">A radio-detected Type Ia supernova with helium-rich circumstellar material </a> <br /></span></li></ul>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-16984417136095792862024-01-02T22:51:00.000-08:002024-02-23T21:49:27.345-08:00JWST Reveals a Surprisingly High Fraction of Galaxies Being Spiral-like<p><a href="https://arxiv.org/abs/2312.12389">arXiv</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">In this letter, we used James Webb Space Telescope (JWST) images from the Cosmic Evolution Early Release Science Survey to visually identify spiral galaxies with redshift 0.5≤z≤4 and stellar mass ≥1010M⊙. Out of 873 galaxies, 216 were found to have a spiral structure.</p><p style="text-align: left;">These fractions are higher than the fractions observed with the Hubble Space Telescope (HST). We even detect possible spiral-like features at redshifts z>3.</p><p style="text-align: left;">This fraction is surprisingly high and implies that the formation of spiral arms, as well as disks, was earlier in the universe. </p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><a href="https://phys.org/news/2024-01-early-universe-spiral-galaxies.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter">Phys.org</a>:</p><p style="text-align: left;"></p><blockquote>Of these galaxies, 216 were classified as spirals. The authors were careful to note that some may be merging galaxies that were misclassified, but even then 108 of the galaxies were unanimously classified as spirals by evaluators. When the team arranged them by redshift, they found that while the fraction of spirals decreased as you went further into the past, the fraction of spirals at redshifts above z = 3 was much higher than expected. When the team calibrated observations, they found about a fifth of galaxies at z = 3 are spiral galaxies. These very early galaxies would have had to become spirals less than two billion years after the Big Bang, meaning that there would have been little time for mergers and collisions to be the cause.</blockquote><p></p><p style="text-align: left;">If spiral galaxies were more common in the early universe than expected, it could indicate that certain conditions or mechanisms favored the formation of spiral structures at that time. This is quite at odds with the current understanding of what structures were favored during these early epochs of the Universe's development. <br /></p><p style="text-align: left;"><br /></p><p style="text-align: left;">Previously on this blog:</p><ul style="text-align: left;"><li style="text-align: left;"> <a href="https://www.jrfarah.blog/2023/03/james-webb-captures-extremely-distant.html">James Webb captures an extremely distant triple-lensed supernova</a></li><li style="text-align: left;"> <a href="https://www.jrfarah.blog/2023/04/webb-telescope-discovers-oldest.html">Webb telescope discovers oldest galaxies ever observed</a> </li><li style="text-align: left;"> <a href="https://www.jrfarah.blog/2023/02/discovery-of-isolated-dark-dwarf-galaxy.html">Discovery of an isolated dark dwarf galaxy in the nearby universe</a> <br /></li></ul>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-32171749012483598012024-01-02T22:38:00.000-08:002024-02-23T21:49:43.075-08:00How many planets could be in the Kuiper Belt?<p><i><a href="https://iopscience.iop.org/article/10.3847/2041-8213/ad13eb/pdf">ApJL</a></i>: </p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Motivated by recent measurements of the free-floating-planet mass
function at terrestrial masses, we consider the possibility that the
solar system may have captured a terrestrial planet early in its
history. We show that ∼1.2 captured free-floating planets with mass
strictly greater than that of Mars may exist in the outer solar system,
with a median predicted distance of ∼1400 au. <br /></p><p style="text-align: left;">To evaluate the expected mass of the most massive captured free-floating
planet as a function of the maximum semimajor axis, given the arguments
presented in Section 2, we implement a Monte Carlo simulation.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;">This is an interesting calculation, but the result of ~1 free-floating planet does not have a reported error and seems extremely sensitive to the mass function. Equation 1 gives the mass function of free-forming planets:</p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"><img alt="" height="49" src="data:image/png;base64,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" width="291" /></p><p>The coefficient on the power-law term has substantial errorbars, changing the result of the mass function by up to 75% if alpha ~ 1. Examining alpha as well, the paper reports that alpha ~ 0.96 \pm 0.47, which would have a substantial effect on the value of the mass function. It wasn't immediately clear how this substantial variation affected the number of planets detected. Figure 1 shows the confidence intervals on the mass estimate for a planet of abundance unity, but I wasn't able to immediately grasp how to convert this into an errorbar on the planet abundance estimate. Then Figure 2 shows the cumulative fraction and expected number of captured free-floating planets, but doesn't show the confidence intervals. So overall, it's hard to assess the free-floating planet abundance estimate from their simulations given the huge spread on the parameters. The estimate changes from ~1 to ~3 with a change of binning, which is expected but also highlights how uncertain the estimate and approach are, so it would been interesting to see a more thorough exploration of this. <br /></p><p><a href="https://phys.org/news/2024-01-planets-kuiper-belt.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter">Phys.org</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">A recent study published in the <i>Astrophysical Journal Letters</i>
investigates the potential existence of Mars-sized free-floating
planets (FFPs)—also known as rogue planets, starless planets, and
wandering planets—that could have been captured by our sun's gravity
long ago and orbit in the outer solar system approximately 1,400
astronomical units (AU) from the sun.</p><p style="text-align: left;">Scientists currently hypothesize that rogue planets are formed from two scenarios: As part of their own solar system
but are then somehow ejected into the cosmos, or they form in
isolation. But what is the significance of studying free-floating
planets, overall?</p><p style="text-align: left;">After conducting approximately 100,000,000 simulations, the results
indicate the potential for the existence of a Mars-sized, or even a
Mercury-sized planetary body somewhere in the outer solar system
approximately 1,400 AU from the Sun.</p></blockquote><p style="text-align: left;"></p><p><a href="https://www.universetoday.com/165014/how-many-planets-could-be-in-the-kuiper-belt/#:~:text=This%20study%20comes%20as%20scientists,some%20hypothesized%20to%20be%20pairs">Universe Today</a><i>:</i></p><p style="text-align: left;"></p><blockquote>Siraj recommends in his study that future work could include gaining
greater understanding of how rogue planets are captured in the first
place, along with investigating observational tests to identify where to
look in the sky for rogue planets, as well. He also notes how
microlensing has become the preferred method in identifying rogue
planets based on past studies. </blockquote><p></p><p>Rogue planet capture is extremely interesting for sure. I'm also super interested in the related phenomenon of JuMBOs (Jupiter-Mass Binary Objects), which are forcing astrophysicists to confront the same tough questions as this study.</p><p><br /></p><p>Previously on this blog:</p><ul style="text-align: left;"><li><a href="https://www.jrfarah.blog/2023/02/an-earth-sized-planet-around-m5-dwarf.html">An Earth-sized Planet around an M5 Dwarf Star at 22 pc</a></li><li><a href="https://www.jrfarah.blog/2023/04/scientists-think-they-know-why.html ">Scientists think they know why interstellar object 'Oumuamua moved so strangely</a> <br /></li></ul>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-65473202915988885602023-12-05T08:50:00.000-08:002024-02-23T21:49:52.807-08:00Saturn's icy moon may hold the building blocks of life<p><a href="https://phys.org/news/2023-12-saturn-icy-moon-blocks-life.html">Phys.org</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Evidence indicates that Saturn's icy moon Enceladus is an 'ocean world'
that contains all three, making it a prime target in the search for
life. </p><p style="text-align: left;">During its 20-year mission, NASA's Cassini spacecraft discovered that
ice plumes spew from Enceladus' surface at approximately 800 miles per
hour (400 m/s). These plumes provide an excellent opportunity to collect
samples and study the composition of Enceladus' oceans and their
potential habitability.</p><p style="text-align: left;">Now, researchers from the University of California San Diego have shown
unambiguous laboratory evidence that amino acids transported in these
ice plumes can survive impact speeds of up to 4.2 km/s, supporting their
detection during sampling by spacecraft. </p></blockquote><p style="text-align: left;"></p><p><a href="https://www.pnas.org/doi/10.1073/pnas.2313447120">PNAS</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">The icy moons of Saturn and Jupiter, Enceladus and Europa, are
particularly promising for hosting life, as they have shown evidence for
the three important criteria: water, energy, and organic chemicals.
Both moons eject their subsurface ocean material as a plume of icy
particles, providing the opportunity to study the ocean composition and
potential habitability via plume flythrough sampling. </p><p style="text-align: left;">We show that amino acids entrained in ice grains can be detected intact
after impact at speeds up to 4.2 km/s and that salt reduces their
detectability, validating the predictions from other model systems. Our
results provide a benchmark for this orbital sampling method to
successfully detect signs of life and for the interpretation of past and
future data.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><br /></p><p style="text-align: left;">I've always been personally excited by the original Enceladus discovery made by Cassini. It was already such a bizarre little moon to begin with, with the smooth southern geography, but the discovery of these liquid water plumes indicating a warm ocean under the surface was absolutely wonderful. There tends to be excitement and interest in finding aliens far outside of Earth, but if we honest-to-goodness to find alien life or at least the building blocks for it, it'll likely be in the plumes of Enceladus, quite close to home.<br /></p><p style="text-align: left;"> <br /></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-80047460711044111272023-11-20T11:16:00.000-08:002024-01-04T09:13:47.521-08:00Detection of long-lasting aurora-like radio emission above a sunspot<p><a href="https://www.nature.com/articles/s41550-023-02122-6" style="font-style: italic;">nature astronomy</a>:</p><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">Here we report observations of long-lasting solar radio bursts with high brightness temperature, wide bandwidth and high circular polarization fraction akin to these auroral and exo-auroral radio emissions, albeit two to three orders of magnitude weaker than those on certain low-mass stars. Spatially, spectrally and temporally resolved analysis suggests that the source is located above a sunspot where a strong, converging magnetic field is present. </p></blockquote><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">Our findings offer new insights into the origin of such intense solar radio bursts and may provide an alternative explanation for aurora-like radio emissions on other flare stars with large starspots.</p></blockquote><div class="separator" style="clear: both; text-align: center;"><a href="https://media.springernature.com/full/springer-static/image/art%3A10.1038%2Fs41550-023-02122-6/MediaObjects/41550_2023_2122_Fig1_HTML.png?as=webp" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="537" data-original-width="800" height="383" src="https://media.springernature.com/full/springer-static/image/art%3A10.1038%2Fs41550-023-02122-6/MediaObjects/41550_2023_2122_Fig1_HTML.png?as=webp" width="571" /></a></div><br /><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">(Figure 1 caption) <b>a</b>, Example of a VLA snapshot image at 1.0 GHz (orange) of the radio emission from the sunspot with the image of the radio-hosting NOAA 12529 AR observed in EUV wavelengths by the AIA, 171 Å (blue), 94 Å (cyan) and 1,600 Å (red) overlaid on the photospheric image observed by the HMI aboard the SDO. Also shown is a VLA 3.8 GHz image (magenta) of the radio emission from the flare site. <b>b</b>, Closer view of the sunspot region (box in <b>a</b>). The 1.0 GHz and 3.8 GHz are shown as yellow and magenta contours, respectively, at 50%, 70% and 90% of the maximum. The white box in b is discussed further at Fig. 4.</p></blockquote><p><a href="https://www.livescience.com/space/the-sun/astronomers-spot-aurora-on-the-sun-for-the-1st-time">LiveScience</a>:</p><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">Scientists have spotted a stunning "aurora-like" display of crackling radio waves over the surface of the sun that is strikingly similar to the Northern Lights on Earth. </p></blockquote><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">"This is quite unlike the typical, transient solar radio bursts typically lasting minutes or hours," lead author Sijie Yu, an astronomer at New Jersey Institute of Technology's Center for Solar-Terrestrial Research (NJIT-CSTR), said in a statement. "It's an exciting discovery that has the potential to alter our comprehension of stellar magnetic processes."</p></blockquote><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">The researchers say their discovery has opened up new ways to study the sun's activity, and they have begun poring through archival data to find hidden evidence of past solar auroras. "We're beginning to piece together the puzzle of how energetic particles and magnetic fields interact in a system with the presence of long-lasting starspots," study co-author Surajit Mondal, a solar physicist at NJIT, said in the statement. "Not just on our own Sun but also on stars far beyond our solar system."</p></blockquote><p>This is a really exciting discovery! The resolution required to do this kind of work is fairly low so it seems completely plausible that past observations of the Sun in radio may have captured these sorts of effects. The duration is also interesting--a week is a long time for solar processes. Something I'm particularly curious about is whether we expect to see more of these now that a long and early solar maximum is just around the corner.</p><p><a href="https://www.weather.gov/news/102523-solar-cycle-25-update#:~:text=The%202019%20panel%2C%20convened%20by,maximum%20sunspot%20number%20of%20115.">NOAA</a>:</p><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">NOAA’s Space Weather Prediction Center (SWPC) issued a revised prediction for solar activity during Solar Cycle 25 that concludes solar activity will increase more quickly and peak at a higher level than that predicted by an expert panel in December 2019. The updated prediction now calls for Solar Cycle 25 to peak between January and October of 2024, with a maximum sunspot number between 137 and 173.</p></blockquote><p>The solar maximum is a period in the solar cycle when the Sun's activity, particularly in terms of sunspots and solar flares, is at its highest. The solar cycle is an approximately 11-year cycle during which the Sun undergoes a regular pattern of changes in solar activity. This cycle is characterized by the waxing and waning of the number of sunspots on the Sun's surface.</p><p>During solar maximum, the number of sunspots is at its peak, and solar activity is generally more intense. Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas. They are associated with strong magnetic activity and are often the source of solar flares and coronal mass ejections (CMEs). It therefore seems pretty reasonable to me that we might expect more of these aurora-like transients, which seemed to form above a large sunspot.</p><p><br /></p><p>Previously on this blog:</p><p></p><ul><li></li><li><a href="https://www.jrfarah.blog/2023/04/global-geomagnetic-perturbation.html">Global Geomagnetic Perturbation Forecasting Using Deep Learning</a></li><li><a href="https://www.jrfarah.blog/2023/02/swpc-reports-x-class-solar-flare.html">SWPC Reports X-Class Solar Flare</a></li><li><a href="https://www.jrfarah.blog/2023/03/potential-comet-for-2024-c2023-a3.html">Potential comet for 2024: C/2023 A3</a></li></ul>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-14375216131967163592023-11-20T11:02:00.000-08:002024-01-04T09:13:58.054-08:00ALMA Achieve Unprecedented Resolution to Observe the Universe<p><a href="https://www.almaobservatory.org/en/announcements/alma-achieve-unprecedented-resolution-to-observethe-universe/#300809c1-00a6-4fc2-8d41-bcf7e5a7d1d7">ALMA Observatory</a>:</p><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">An international team of astronomers and engineers has successfully conducted an observation that achieved an extraordinary resolution of 5 milliarcseconds, using ALMA's highest frequency Band 10 receiver and an array configuration that spans 16 kilometers. </p></blockquote><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">This groundbreaking observation allowed the team to capture unprecedented details of a maser around an evolved star within the Milky Way. </p></blockquote><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">Yoshiharu Asaki, the ALMA Astronomer who led this project, highlighted the collaborative effort: "This remarkable achievement in high-resolution imaging through ALMA's advanced capabilities marks a significant milestone in our quest to understand the Universe. The success of the Band 10 high-resolution observation showcases our commitment to innovation and reinforces ALMA's position as a leader in astronomical discovery. We are excited about the new possibilities for the scientific community."</p></blockquote><p>5 milliarcseconds is certainly an impressive resolution. For comparison, the VLBI array that examined SN 1993J at 8 GHz achieved a resolution of ~1 milliarcsecond. For a single station to achieve this is incredible.</p><p><a href="https://iopscience.iop.org/article/10.3847/1538-4357/acf619"><i>ApJ</i></a>:</p><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">The Atacama Large Millimeter/submillimeter Array (ALMA) was used in 2021 to image the carbon-rich evolved star R Lep in Bands 8–10 (397–908 GHz) with baselines up to 16 km. The goal was to validate the calibration...and the imaging procedures required to obtain the maximum angular resolution achievable with ALMA.</p></blockquote><p>It's quite interesting seeing that the paper is very focused on what amounts to a test and validation of the capabilities of ALMA, but still got good coverage in the media. This isn't a bad thing at all--usually buzzwordy science results grab all the attention--and it's nice to see a shift towards interest in some of the technical aspects of the field.</p><p> </p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-72713261848489062512023-09-11T09:24:00.002-07:002023-09-11T09:24:17.127-07:00Mysterious Black Hole Twins May Fuel The Brightest Galaxies in Space<p><i><a href="https://iopscience.iop.org/article/10.3847/1538-4357/accbbc">ApJ</a></i>: </p><p style="margin-left: 40px; text-align: left;">We propose that AGN flux variability and changes in jet morphology can
both be of deterministic nature, i.e., having a geometric/kinetic origin
linked to the time-variable Doppler beaming of the jet emission as its
direction changes due to precession (and nutation).</p><p style="margin-left: 40px; text-align: left;">We demonstrate this modulating power of precession for OJ 287. For the
first time, we show that the spectral state of the spectral energy
distribution (SED) can be directly related to the jet's precession phase.</p><p style="margin-left: 40px; text-align: left;">We show that for OJ 287 precession seems to dominate the long-term
variability (≳1 yr) of the AGN flux, SED spectral state, and jet
morphology, while stochastic processes affect the variability on short
timescales (≲0.2 yr).</p><p style="text-align: left;">OJ 287 is an incredibly interesting object. It's a massive quasar that we've observed periodic outbursts in for >100 years, which are attributed to a ~100 million solar mass black hole orbiting a much larger 18 billion solar mass black hole. (For context, the huge M87 black hole was "only" 6 billion solar masses). This paper specifically attributes the emission to the precessing jet caused by the orbiting black holes.<br /></p><p style="text-align: left;"><a href="https://www.sciencealert.com/mysterious-black-hole-twins-may-fuel-the-brightest-galaxies-in-space">ScienceAlert</a>:</p><p style="margin-left: 40px; text-align: left;">Led by astronomer Silke Britzen of the Max Planck Institute for Radio Astronomy in Germany, an international team studied 12 blazar galaxies, finding an interpretation of circling black holes could be applied to all of them.</p><p style="margin-left: 40px; text-align: left;">This could be a clue as to how supermassive black holes millions to
billions of times the mass of the Sun grow to such tremendous size.</p><p style="margin-left: 40px; text-align: left;">We currently lack instrumentation with the resolution to observe the disk architecture that would reveal these binary black holes, but continued monitoring of the precession, as well as long-term observation of other blazars, could continue to yield information about their existence.</p><p style="text-align: left;"><a href="https://www.space.com/wobbly-jets-evidence-supermassive-black-hole-binaries">Space.com</a>:</p><p style="margin-left: 40px; text-align: left;">Jets blasted out by feeding supermassive black holes at the hearts of active galaxies could brighten and curve due to a "wobble" caused by a second orbiting supermassive black hole, a new study reports.</p><p style="margin-left: 40px; text-align: left;">"We present evidence and discuss the possibility that it is, in fact, the precession of the jet source, either caused by a supermassive binary black hole at the footpoint of the jet or — less likely — by a warped accretion disk around a single black hole, that is responsible for the observed variability," study leader Silke Britzen, a researcher at the Max Planck Institute for Radio Astronomy in Bonn, Germany, said in a statement.</p><p style="margin-left: 40px; text-align: left;">The team can't fully rule out factors in jet physics, such as shock
waves or instabilities in the jet, or even magnetic fields, as the
driving force behind the curved jets. However, they argue, the jets in
question wouldn't be quite as curvy or as bright if it weren't for their
wobble. <br /></p><p style="text-align: left;"> </p><p style="text-align: left;">Previously on this blog:</p><ul style="text-align: left;"><li style="text-align: left;"><a href="https://www.jrfarah.blog/2023/02/observational-evidence-for-cosmological.html">Observational Evidence for Cosmological Coupling of Black Holes and its Implications for an Astrophysical Source of Dark Energy </a></li><li style="text-align: left;"><a href="https://www.jrfarah.blog/2023/02/spherical-symmetry-in-kilonova.html">Spherical symmetry in the kilonova AT2017gfo/GW170817 </a><br /> </li></ul><p style="text-align: left;"> </p><p style="text-align: left;"> </p><p style="text-align: left;"> <br /></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-89060759665273016322023-06-04T17:09:00.001-07:002023-06-04T17:09:04.731-07:00SN 2023ixf early photometry<p>This supernova just exploded in the galaxy M101, just 6 Mpc away, making it the closest supernova since SN 2011fe. Research groups around the world are scrambling to conduct analyses of this object. Some have already started popping up on arXiv.</p><p><a href="https://arxiv.org/abs/2306.00263">arXiv</a>:</p><p></p><blockquote><p>We present the early-stage analysis of the low-resolution (R=1000) optical spectra and the near-infrared light curves of the bright Type II supernova (SN II) 2023ixf in the notable nearby face-on spiral galaxy M101, which are obtained since t=1.7 until 8.0 d.</p><p>Compared with SNe II showing the flash-ionized features, we suggest that this SN could be categorized into high-luminosity SNe II with a nitrogen/helium-rich circumstellar material (CSM), e.g., SNe 2014G, 2017ahn, and 2020pni. </p><p>These observational facts support that SN 2023ixf is well consistent with a high-luminosity SN II with the dense nitrogen/helium-rich CSM.</p><p></p></blockquote><p>It's great to see the comparisons to previous objects. 23ixf doesn't have too many remarkable qualities aside from some very early flash features (and its proximity), but it's difficult to find good comparisons since we really don't get to observe SNe early this often.</p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-6455778597033604212023-05-17T23:57:00.007-07:002023-05-18T00:00:34.173-07:00A radio-detected Type Ia supernova with helium-rich circumstellar material<p><a href="https://arxiv.org/abs/2210.07725">arXiv</a>:</p><blockquote style="border: none; margin: 0px 0px 0px 40px; padding: 0px;"><p style="text-align: left;">However, despite extensive efforts, no SN Ia has ever been detected at radio wavelengths, which suggests a clean environment and a companion star that is itself a degenerate WD star. Here we report on the study of SN 2020eyj, a SN Ia showing helium-rich CSM, as revealed by its spectral features, infrared emission and, for the first time in a SN Ia, a radio counterpart. Based on our modeling, we conclude the CSM likely originates from a single-degenerate (SD) binary system where a WD accretes material from a helium donor star, an often hypothesized formation channel for SNe Ia. </p></blockquote><p><a href="https://www.nature.com/articles/s41586-023-05916-w">nature</a>: </p><blockquote style="border: none; margin: 0px 0px 0px 40px; padding: 0px;"><p style="text-align: left;">The CSM interaction in SN 2020eyj is also confirmed, for the first time in a SN Ia, through the detection of a radio counterpart, at a frequency of 5.1 GHz at 605 and 741 days after the first detection. Follow-up in the X-rays did not yield a detection. We model the radio synchrotron emission, which results from the shock interaction between the ejecta and the CSM.</p></blockquote><blockquote style="border: none; margin: 0px 0px 0px 40px; padding: 0px;"><p style="text-align: left;">For the SD shell model, the radio detections are best explained with a CSM mass of M_csm = 0.36 M⊙ (see ‘CSM shells’ section in Methods), with the expectation that the radio light curve will start to drop off rapidly at around 900 days. </p></blockquote><p> </p><p> Previously on this blog:</p><ul style="text-align: left;"><li><a href="https://www.jrfarah.blog/2023/03/initial-flash-and-spectral-formation-of.html">Initial Flash and Spectral Formation of Type Ia Supernovae with An Envelope: Applications to Over-luminous SNe Ia</a></li><li><a href="https://www.jrfarah.blog/2023/05/constraining-type-ia-supernova.html">Constraining Type Ia Supernova Progenitors the Apian Way</a></li><li><a href="https://www.jrfarah.blog/2023/03/the-core-degenerate-scenario-for-type.html">The core degenerate scenario for the type Ia supernova SN 2020eyj<br /></a></li><br /></ul><p></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-22762500149651338612023-05-08T16:06:00.002-07:002024-02-23T21:03:27.428-08:00Update to: Evidence of near-ambient superconductivity in a N-doped lutetium hydride<p><a href="https://www.science.org/content/article/breakthrough-or-bust-claim-room-temperature-superconductivity-draws-fire">Science</a>:</p><blockquote><p>Given the questions, several scientists say Dias should make his data public. “I am unhappy that Dias is supposedly not cooperating with researchers who are questioning his data,” says Marvin Cohen, a theoretical physicist at UC Berkeley. Schilling is blunt: “I told Dias to give [Hirsch] the raw data, for heaven’s sake.”</p></blockquote><blockquote><p>In his email [responding to Hirsch's request for the raw data], Dias wrote, “Given that you have an active comment on our work, we consider such a request would not be reasonable.” Frustrated, Hirsch requested the data from Nature and the National Science Foundation (NSF), which funded the work. On 30 August, Nature appended an editor’s note to Dias’s paper saying: “The editors of Nature have been alerted to undeclared access restrictions relating to the data behind this paper. We are working with the authors to correct the data availability statement.” NSF and the University of Rochester both tell Science they cannot comment on possible investigative matters.</p></blockquote><p>A theoretical analysis on the theoretical feasibility of superconductivity in lutetium hydride was published. The results add an interesting dimension to the controversy.</p><p><a href="https://pubs.aip.org/aip/mre/article/8/3/038402/2887777/First-principles-study-on-the-conventional">AIP</a>:</p><blockquote><p>Recently, room-temperature superconductivity has been reported in a nitrogen-doped lutetium hydride at near-ambient pressure [Dasenbrock-Gammon et al., Nature 615, 244 (2023)]. </p></blockquote><blockquote><p>Here, we systematically study the phase diagram of Lu–N–H at 1 GPa using first-principles calculations, and we do not find any thermodynamically stable ternary compounds.</p></blockquote><blockquote><p>Our theoretical results show that the Tc values of N-doped LuH3 estimated using the Allen–Dynes-modified McMillan equation are much lower than room temperature.</p></blockquote><p>The conclusion seems to be that, based on existing theory, it is not possible to form a stable combination of lutetium, nitrogen, and hydrogen. </p><blockquote><p>Notably, all predicted potential ternary compounds lie above the convex hull at 1 GPa. Thus, no ternary Lu–N–H compounds can remain thermodynamically stable at this pressure, which is consistent with the main results of Xie et al.26</p></blockquote><p>And even if it were, it seems it would superconduct at far lower than room temperature, in line with existing experiments. </p><blockquote><p>Our simulations show that the lowest T_c is 4 K for LuH3 without doping. In addition, T_c increases with increasing N-doping concentration; thus, doping N atoms into LuH3 will increase T_c. However, the highest T_c in this VCA calculation is 22 K, obtained with 1% N-doping at 30 GPa, which is much lower than room temperature.</p></blockquote><p>It's worth noting that 30 GPa is about 300 kbar, which is 30 times higher than the pressures reported in Dias et al. (2023). Further investigation is needed, but it seems theoretically unlikely to produce a material like the doped LuNH3 at the reported temperatures and pressures. Certainly even less likely for it to superconduct at room temperatures. This is based on existing theory, so the possibility remains that Dias et al. have discovered an exciting new effect that will require more advanced models to explain. </p><p><br /></p><p>Previously on this blog:</p><p></p><ul style="text-align: left;"><li><a href="https://www.jrfarah.blog/2023/03/evidence-of-near-ambient.html">Evidence of near-ambient superconductivity in a N-doped lutetium hydride</a></li></ul><p></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-5787348746602866322023-05-07T22:03:00.004-07:002023-05-08T16:07:12.593-07:00Friends of Pando release 360 degree photographic data<p><a href="https://www.stgeorgeutah.com/news/archive/2023/04/30/agl-explore-a-trembling-giant-from-home-friends-of-pando-release-360-degree-photographic-data/">St. George</a>:</p><blockquote><p>Armed with a mission, researchers, volunteers and citizen scientists navigated a trembling giant’s rough terrain, toting high-tech camera equipment and collecting data. Recently, Friends of Pando released the first of many data sets from the survey, allowing individuals from across the globe to study and experience one of the world’s largest organisms — Pando — from the comfort of their living rooms.</p></blockquote><p>The Pando photographic survey is a hugely impressive scientific and artistic accomplishment, cataloging vast swathes of the Pando organism with enough detail and precision to enable rigorous analyses through the exploitation of modern imaging methods. </p><blockquote><p>Despite its massive size, weighing an estimated 13 million pounds and consisting of over 40,000 trees, Pando is a single organism, according to the Forest Service. The tree, the largest known aspen clone, was germinated from a single seed. It regenerates via “suckering,” where it sends up new shoots, or saplings, from its root system. Pando means “I spread” in Latin.</p></blockquote><blockquote><p>The tree, first observed in 1976, is thousands of years old and boasts an estimated 47,000 branches, the release states. “Little is known about the workings of the tree,” and the survey will mark the first time the organism has been inventoried.</p></blockquote><p><a href="https://www.prnewswire.com/news-releases/earth-day-2023-friends-of-pando-begins-publishing-record-of-worlds-largest-tree-301799826.html">PRNewsWire</a>:</p><blockquote><p>Developed in collaboration with Fishlake National Forest and Snow College Richfield, the record offers immediate and long-term value for field and remote research efforts. Documenting Pando every 7m with high accuracy, Oditt says the plot map itself has already been used for field research planning. Long-term, the maps and image data sets can be replicated to monitor Pando for generations to come. For remote research, the system offers a flexible model that allows scientists to use the data sets as provided or, mix-and-match recorded locations to design areas of interest. This work, which explores the use of advanced imaging models and statistical techniques, can provide insights on topics such as disease, regeneration and ground cover.</p></blockquote>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-80665626607650645832023-05-07T21:54:00.004-07:002023-05-18T00:00:08.245-07:00Constraining Type Ia Supernova Progenitors the Apian Way<p><a href="https://arxiv.org/abs/2305.03071">arXiv</a>:</p><blockquote><p>We present very early photometric and spectroscopic observations of the Type Ia supernova (SN) 2023bee, starting about 8 hours after the explosion, which reveal a strong excess in the optical and nearest UV (U and UVW1) bands during the first several days of explosion.</p></blockquote><blockquote><p>We find a good match to the Kasen model in which a main-sequence companion star stings the ejecta with a shock as they buzz past. Models of double detonations, shells of radioactive nickel near the surface, interaction with circumstellar material, and pulsational-delayed detonations do not provide good matches to our light curves. We also observe signatures of unburned material, in the form of carbon absorption, in our earliest spectra.</p></blockquote><p>This is an exciting result out of my research group at Las Cumbres Observatory!</p><p></p><blockquote>Taken together, our observations above suggest that the emission from SN 2023bee during the first few days after explosion consists of typical Type Ia SN spectral features plus an additional hot continuum component. </blockquote><p></p><blockquote><p>This Letter demonstrates the power of using very high-cadence, multiband photometry of young, nearby Type Ia SNe to constrain their progenitor systems, which is only possible with specially designed robotic facilities like the DLT40 Survey, Las Cumbres Observatory, and Swift. </p></blockquote><p><br /></p><p>Previously on this blog:</p><p></p><ul style="text-align: left;"><li><a href="https://www.jrfarah.blog/2023/03/photometry-and-spectroscopy-of-type-icn.html">The diverse properties of the ejecta and circumstellar matter of Type Icn SNe</a></li><li><a href="https://www.jrfarah.blog/2023/03/the-core-degenerate-scenario-for-type.html">The core degenerate scenario for the type Ia supernova SN 2020eyj</a></li></ul><p></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-42456616636496463372023-04-07T12:43:00.005-07:002023-04-07T12:43:58.215-07:00Scientists think they know why interstellar object 'Oumuamua moved so strangely<p><a href="https://www.nature.com/articles/s41586-022-05687-w">nature</a>:</p><blockquote><p>In 2017, 1I/‘Oumuamua was identified as the first known interstellar object in the Solar System1. Although typical cometary activity tracers were not detected, ‘Oumuamua showed a notable non-gravitational acceleration. </p></blockquote><blockquote><p>Here we report that the acceleration of ‘Oumuamua is due to the release of entrapped molecular hydrogen that formed through energetic processing of an H2O-rich icy body...We show that this mechanism can explain many of ‘Oumuamua’s peculiar properties without fine-tuning.</p></blockquote><p><a href="https://news.uchicago.edu/story/surprisingly-simple-explanation-interstellar-visitor-oumuamuas-weird-orbit">UChicago</a>:</p><blockquote><p>But when ‘Oumuamua was discovered, it had no tail and was too small and too far from the sun to capture enough energy to eject much water, which led astronomers to speculate wildly about its composition and what was pushing it outward. Was it a hydrogen iceberg? A large, fluffy snowflake pushed by light pressure from the sun? </p></blockquote><blockquote><p>Perhaps, they wondered, its strange acceleration actually came from hydrogen...If so, perhaps the force produced by the hydrogen outgassing could explain ‘Oumuamua’s odd movement.</p></blockquote><blockquote><p>“For a comet several kilometers across, the outgassing would be from a really thin shell relative to the bulk of the object, so both compositionally and in terms of any acceleration, you wouldn’t necessarily expect that to be a detectable effect,” she said. “But because ‘Oumuamua was so small, we think that it actually produced sufficient force to power this acceleration.”</p></blockquote><p><a href="https://www.npr.org/2023/03/22/1164814086/scientists-think-they-know-why-interstellar-object-oumuamua-moved-so-strangely">NPR</a>:</p><blockquote><p>Scientists have come up with a simple explanation for the strange movements of our solar system's first known visitor from another star.</p></blockquote><blockquote><p>Oddly, this interstellar object appeared to be slightly accelerating in a way that normally is associated with the outgassing of some kind of material. But astronomers couldn't detect any comet-like tail of dust or gas...Now, though, in the journal Nature, two researchers say the answer might be the release of hydrogen from trapped reserves inside water-rich ice.</p></blockquote><blockquote><p>"It's an interesting, creative idea," says Karen Meech, with the Institute for Astronomy at the University of Hawaii, who leads the team that initially found and observed 'Oumuamua. "It doesn't require a super-exotic mechanism." But she still thinks it's possible that 'Oumuamua is just a regular, ordinary comet that released enough water, carbon dioxide, and carbon monoxide to account for the acceleration, and astronomers just didn't detect it.</p></blockquote><p>Meech also finds the elongated shape of the object far more intriguing than the odd acceleration, which could be explained by low quantities of ordinary comet ejecta. The currently accepted explanation for the shape is that 'Oumuamua like objects are kicked out during planetary formation.</p><p><a href="https://www.scientificamerican.com/article/oumuamua-like-objects-might-supercharge-planet-formation/">Scientific American</a>:</p><blockquote><p>Planet formation is a messy process in which worlds emerge from the embryonic disks of gas and dust that give birth to stars themselves. As debris clumps together and grows, whirling around the central star, its gravity pushes and scatters smaller clumps throughout the disk. </p></blockquote><blockquote><p>Multiple theories postulate that such processes are responsible for sending ‘Oumuamua our way. Researchers have proposed that the strange object may have been thrown out of its young system after a brush with a giant planet there.</p></blockquote><p><a href="https://solarsystem.nasa.gov/asteroids-comets-and-meteors/comets/oumuamua/in-depth/">NASA</a>: </p><blockquote><p>The object, named ‘Oumuamua by its discoverers, is up to one-quarter mile (400 meters) long and highly-elongated—perhaps 10 times as long as it is wide. That aspect ratio is greater than that of any asteroid or comet observed in our solar system to date. While its elongated shape is quite surprising, and unlike objects seen in our solar system, it may provide new clues into how other solar systems formed. </p></blockquote>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-32598102652445122232023-04-04T10:01:00.008-07:002023-04-04T14:09:11.742-07:00Global Geomagnetic Perturbation Forecasting Using Deep Learning<p><a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022SW003045">AGU</a>:</p><blockquote><p>Geomagnetically Induced Currents (GICs) arise from spatio-temporal changes to Earth's magnetic field, which arise from the interaction of the solar wind with Earth's magnetosphere, and drive catastrophic destruction to our technologically dependent society. Hence, computational models to forecast GICs globally with large forecast horizon, high spatial resolution and temporal cadence are of increasing importance to perform prompt necessary mitigation.</p></blockquote><blockquote><p>Our model outperforms, or has consistent performance with state-of-the-practice high time cadence local and low time cadence global models, while also outperforming/having comparable performance with the benchmark models. Such quick inferences at high temporal cadence and arbitrary spatial resolutions may ultimately enable accurate forewarning of dB/dt for any place on Earth, resulting in precautionary measures to be taken in an informed manner.</p></blockquote><p><a href="https://phys.org/news/2023-03-nasa-enabled-ai-solar-storms.html">Phys.org</a>: </p><blockquote><p>Like a tornado siren for life-threatening storms in America's heartland, a new computer model that combines artificial intelligence (AI) and NASA satellite data could sound the alarm for dangerous space weather.</p></blockquote><blockquote><p>The model uses AI to analyze spacecraft measurements of the solar wind (an unrelenting stream of material from the sun) and predict where an impending solar storm will strike, anywhere on Earth, with 30 minutes of advance warning. This could provide just enough time to prepare for these storms and prevent severe impacts on power grids and other critical infrastructure.</p></blockquote><blockquote><p>To help prepare, an international team of researchers at the Frontier Development Lab—a public-private partnership that includes NASA, the U.S. Geological Survey, and the U.S. Department of Energy—have been using artificial intelligence (AI) to look for connections between the solar wind and geomagnetic disruptions, or perturbations, that cause havoc on our technology. The researchers applied an AI method called "deep learning," which trains computers to recognize patterns based on previous examples. They used this type of AI to identify relationships between solar wind measurements from heliophysics missions (including ACE, Wind, IMP-8, and Geotail) and geomagnetic perturbations observed at ground stations across the planet. </p></blockquote><p><br /></p><p>Previously on this blog:</p><p></p><ul style="text-align: left;"><li><a href="https://www.jrfarah.blog/2023/02/swpc-reports-x-class-solar-flare.html">SWPC Reports X-Class Solar Flare</a></li><li><a href="https://www.jrfarah.blog/2023/03/potential-comet-for-2024-c2023-a3.html">Potential comet for 2024: C/2023 A3</a></li></ul><p></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-44139802480374672222023-04-04T09:49:00.002-07:002023-04-04T09:49:25.047-07:00Using dark matter distribution to test the cosmological model<p> <a href="https://arxiv.org/abs/2304.00704">arXiv</a>:</p><blockquote><p>We present cosmology results from a blinded joint analysis of cosmic shear, ξ±(ϑ), galaxy-galaxy weak lensing, ΔΣ(R), and projected galaxy clustering, wp(R), measured from the Hyper Suprime-Cam three-year (HSC-Y3) shape catalog and the Sloan Digital Sky Survey (SDSS) DR11 spectroscopic galaxy catalog - a 3×2pt cosmology analysis.</p></blockquote><blockquote><p>We obtain a robust constraint on the cosmological parameters for the flat ΛCDM model: S8=σ8(Ωm/0.3)0.5=0.763+0.040−0.036 (68% C.I.), or the best-constrained parameter given by S′8=σ8(Ωm/0.3)0.22=0.721±0.028, determined with about 4% fractional precision.</p></blockquote><p><a href="https://phys.org/news/2023-04-dark-cosmological.html">Phys.org</a>:</p><blockquote><p>An international team of astrophysicists and cosmologists at various institutes including the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) have submitted a set of five papers, measuring a value for the "clumpiness" of the universe's dark matter, known to cosmologists as S8, of 0.76, which aligns with values that other gravitational lensing surveys have found in looking at the relatively recent universe, but it does not align with the value of 0.83 derived from the cosmic microwave background, which dates back to the universe's origins when the universe was about 380,000 years old. </p></blockquote><p>Previously on this blog: </p><p></p><ul style="text-align: left;"><li><a href="https://www.jrfarah.blog/2023/02/discovery-of-isolated-dark-dwarf-galaxy.html">Discovery of an isolated dark dwarf galaxy in the nearby universe</a></li></ul><p><br /></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-15505503951866188522023-04-04T09:22:00.004-07:002023-04-04T09:22:26.395-07:00Webb telescope discovers oldest galaxies ever observed<p><a href="https://www.nature.com/articles/s41550-023-01921-1">Nature Astronomy</a>:</p><blockquote><p>Here we identify four galaxies located in the JWST Advanced Deep Extragalactic Survey Near-Infrared Camera imaging with photometric redshifts z of roughly 10–13. These galaxies include the first redshift z > 12 systems discovered with distances spectroscopically confirmed by JWST in a companion paper.</p></blockquote><blockquote><p>Taken together, these measurements show that the first galaxies contributing to cosmic reionization formed rapidly and with intense internal radiation fields.</p></blockquote><p><a href="https://phys.org/news/2023-04-webb-telescope-oldest-galaxies.html">Phys.org</a>:</p><blockquote><p>The James Webb Space Telescope has discovered the four most distant galaxies ever observed, one of which formed just 320 million years after the Big Bang when the universe was still in its infancy, new research said on Tuesday.</p></blockquote><blockquote><p>Stephane Charlot, a researcher at the Astrophysics Institute of Paris and co-author of the two new studies, told AFP that the farthest galaxy—called JADES-GS-z13-0—formed 320 million years after the Big Bang. That is the greatest distance ever observed by astronomers, he said.</p></blockquote><blockquote><p>However in February, the discovery of six massive galaxies from 500-700 million years after the Big Bang led some astronomers to question the standard model.</p></blockquote><blockquote><p>Those galaxies, also observed by the Webb telescope, were bigger than thought possible so soon after the birth of the universe—if confirmed, the standard model could need updating. </p></blockquote><p>This analysis does not include even earlier candidates that JWST has discovered that are yet to be confirmed. </p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-11186341743292259702023-03-14T22:21:00.003-07:002024-02-23T21:51:38.642-08:00Evidence of near-ambient superconductivity in a N-doped lutetium hydride<p><a href="https://www.nature.com/articles/s41586-023-05742-0">Nature</a>: </p><blockquote><p>The absence of electrical resistance exhibited by superconducting materials would have enormous potential for applications if it existed at ambient temperature and pressure conditions. Despite decades of intense research efforts, such a state has yet to be realized.</p></blockquote><blockquote><p>Here we report evidence of superconductivity on a nitrogen-doped lutetium hydride with a maximum Tc of 294 K at 10 kbar, that is, superconductivity at room temperature and near-ambient pressures. [Superconductivity was verified via] temperature-dependent resistance with and without an applied magnetic field, the magnetization (M) versus magnetic field (H) curve, a.c. and d.c. magnetic susceptibility, as well as heat-capacity measurements.</p></blockquote><p><a href="https://www.independent.co.uk/tech/superconducting-material-lutetium-chemical-energy-b2300242.html">The Independent</a>: </p><blockquote><p>Scientists have discovered a new material that could be set to change the entire world. Researchers say they have created a superconducting material that works at both a temperature and a pressure low enough to actually use it in practical situations.</p></blockquote><blockquote><p>Professor Dias and the team made the material by taking a rare earth metal named lutetium and mixed it with hydrogen and a small part of nitrogen. They were then left to react for two or three days, at high temperatures.</p></blockquote><blockquote><p>To work, the material still requires being heated to 20.5 degrees Celsius and compressed to about 145,000 psi. But that is vastly less intense than other, similar materials – including those announced in 2020 by Professor Dias that brought excitement and scepticism from scientists.</p></blockquote><p><a href="https://www.wsj.com/articles/superconductor-breakthrough-energy-reddmatter-90dfa165?mod=business_minor_pos13">Wall Street Journal</a>:</p><blockquote><p>U.S. scientists say they have produced the first commercially accessible material that eliminates the loss of energy as electricity moves along a wire, a breakthrough that could mean longer-lasting batteries, more-efficient power grids and improved high-speed trains.</p></blockquote><p><a href="https://www.nytimes.com/2023/03/08/science/room-temperature-superconductor-ranga-dias.html">New York Times</a>: </p><blockquote><p>The new superconductor consists of lutetium, a rare earth metal, and hydrogen with a little bit of nitrogen mixed in. It needs to be compressed to a pressure of 145,000 pounds per square inch before it gains its superconducting prowess...But it is also less than one one-hundredth of what the 2020 result required, which was akin to the crushing forces found several thousand miles deep within the Earth. </p></blockquote><blockquote><p>“This is the start of the new type of material that is useful for practical applications,” Ranga P. Dias, a professor of mechanical engineering and physics at the University of Rochester in New York, said to a room packed full of scientists on Tuesday at a meeting of the American Physical Society in Las Vegas.</p></blockquote><blockquote><p>In the paper, the researchers reported that the pink crystals exhibited key properties of superconductors, like zero resistance, at temperatures up to 70 degrees Fahrenheit.</p></blockquote><blockquote><p>“I’m cautiously optimistic,” said Timothy Strobel, a scientist at the Carnegie Institution for Science in Washington who was not involved in Dr. Dias’s study. “The data in the paper, it looks great.”</p></blockquote><p>This is a very exciting and potentially game-changing result. The hunt for a room-temperature superconductor has been frantic and long-lasting, due to properties that would enable them to revolutionize many aspects of modern technology. For its part, the paper is detailed and seems to have taken great care to demonstrate superconductivity via multiple channels. There is some controversy surrounding the results, which can be separated into two categories:</p><p></p><ol style="text-align: left;"><li>Concerns about the validity of the results. Are they reproducible, or was this a fluke event? Is the new material really stable enough at STP to be viable?</li><li>Ethical concerns about the results. The particular research group that put out this astonishing result has had a fraught past, with <a href="https://www.nature.com/articles/s41586-020-2801-z">retracted papers</a> and <a href="https://www.science.org/content/article/preprint-server-removes-inflammatory-papers-superconductor-controversy">extended drama</a> over previous results in a similar vein. Additionally, arguably the largest fraudulent scandal in scientific history (the infamous <a href="https://en.wikipedia.org/wiki/Sch%C3%B6n_scandal">Schön scandal</a>) was focused on this subfield, which tends to attract grandiose and wild claims.</li></ol><div><a href="https://physics.aps.org/articles/v16/39">APS</a>:</div><div><div></div><blockquote><div>For such a claim, one might expect jubilation and animated questions, but the audience’s response was hesitant—a few people politely asked technical questions, such as how well Dias’ team could control the amount of nitrogen in the sample. There was no whooping or cheering. The audience had been here before.</div></blockquote><blockquote><p>In 2020, Dias’ team announced in a paper in Nature that they had created a material, carbonaceous sulfur hydride, that superconducted at 287 K and 267 GPa. Researchers and news outlets lauded the finding, but the paper was <a href="https://physics.aps.org/articles/v16/40">retracted</a> two years later after outside researchers found oddities in the results.</p></blockquote><blockquote><p>Another part of that wariness arises because, to date, no one has independently reproduced Dias’ team’s results. This lack of verification was raised by Jorge Hirsch of the University of California, San Diego, in the last talk of the session in which Dias and his team spoke. </p></blockquote><p><a href="https://www.quantamagazine.org/room-temperature-superconductor-discovery-meets-with-resistance-20230308/">Quanta</a>: </p><blockquote><div>While the announcement has been greeted with enthusiasm by some scientists, others are far more cautious, pointing to the research group’s controversial history of alleged research malfeasance. (Dias strongly denies the accusations.) </div></blockquote><blockquote><p>But incidents involving the team’s previous work — including but not limited to a near-room-temperature superconductivity claim published in Nature in 2020 and retracted late last year — have cast a shadow across today’s announcement. “It’s hard to not wonder if some of the same problems that have gone unaddressed in previous work also exist in the new work,” Hamlin said. </p></blockquote></div><p></p><blockquote><p>“There is a lot of evidence for superconductivity here if you take it at face value,” said Jorge Hirsch, a physicist at the University of California, San Diego. “But I do not believe any of what these authors say. I am not sold at all.”</p></blockquote><blockquote><p>Hirsch said his mistrust stems from a long history of allegations of research malfeasance made against previous and current members of the group, many of which he has pressed. Most recently, in 2020 Dias and his co-authors published a study of a carbonaceous sulfur hydride...Almost immediately, a handful of experts spotted unusual patterns in the data used to verify the material’s response to magnetic fields. When [they] released their raw data a year later in the form of a 149-page document, they detailed an unusual and complicated method for eliminating background magnetic interference — one they said was necessary for them to detect the tiny magnetic field rejected by the small sample. This method was inconsistent with how they’d described the procedure in the original paper, which led Nature to issue a <a href="https://www.nature.com/articles/s41586-020-2801-z">retraction</a> last September. </p></blockquote><blockquote><p>Hirsch and other physicists allege that the misconduct goes beyond a misleading mix-up regarding the magnetic background. In September, [they] published a claim that what Dias and Salamat had released as raw CSH data was actually derived from the published data. “[We] proved basically mathematically that the raw data are not measured in the laboratory; they are fabricated,” Hirsch said. Hamlin independently released a <a href="https://arxiv.org/pdf/2210.10766.pdf">preprint</a> last October claiming that the electrical resistivity data also appeared to have been processed in an undisclosed manner — a new allegation atop the issue that led to the 2022 retraction.<span> </span> </p></blockquote><blockquote><p>Yet the CSH paper isn’t the only related work under fire. One co-author of the CSH paper, Mathew Debessai, was the first author on a 2009 study claiming superconductivity in a third material, europium, which was later retracted for presenting altered data...Others have also <a href="https://pubpeer.com/publications/F342DD2D2E72E5E2FD507089562B94?utm_source=Chrome&utm_medium=BrowserExtension&utm_campaign=Chrome">argued</a> that some of the data in another of Dias’ recent papers was duplicated from data taken while the team was studying a completely different substance.</p></blockquote><p>Here is a figure summarizing the data believed to be duplicated. The zoom-ins to below the 120 K range look remarkably similar. </p><p><a href="https://pubpeer.com/publications/F342DD2D2E72E5E2FD507089562B94?utm_source=Chrome&utm_medium=BrowserExtension&utm_campaign=Chrome">PubPeer</a>: </p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEjLgEuuAbF_ngFxGYHIIbT1N34oc1As35XoBwcIzQelJY1bz_tOgk1hTjl_pqThU7M92B6rYsKT62pgICr3gqGEFs7vcKLpBfonho3wEBjNuRSwnJXdQ638sAbPyxCZbkh8uOafeAU06ngc_vHP0M5mF5Jbz0tLFnx6vh2q3Y1avTrq86BUDjTiCm75Nw" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="705" data-original-width="564" height="407" src="https://blogger.googleusercontent.com/img/a/AVvXsEjLgEuuAbF_ngFxGYHIIbT1N34oc1As35XoBwcIzQelJY1bz_tOgk1hTjl_pqThU7M92B6rYsKT62pgICr3gqGEFs7vcKLpBfonho3wEBjNuRSwnJXdQ638sAbPyxCZbkh8uOafeAU06ngc_vHP0M5mF5Jbz0tLFnx6vh2q3Y1avTrq86BUDjTiCm75Nw=w326-h407" width="326" /></a></div><br /><p></p><blockquote><p>Figure 2: Comparison of data on GeS and corresponding data purportedly measured on MnS... However, if we restrict our view to only the data below 120 K (right panels), we find that the data are essentially identical, within the precision of the extraction process. No transformations have been applied to the data. </p></blockquote><blockquote><p>Considering only the data below 120 K, there is essentially perfect agreement of the shapes of three different pairs of curves within the limitations of the digitization methods. It can not be reasonably concluded that this could occur by coincidence across three different data sets appearing in two different figures. Can the authors please check if an error led to the GeSe data being used in the MnS paper? </p></blockquote><p>A big problem with confirming their results is that it can be challenging to ensure a recipe is followed exactly. Confirmation could be provided if Dias and his team shared the actual material, but they are unwilling to do so for proprietary reasons.</p><p><a href="https://www.science.org/content/article/revolutionary-blue-crystal-resurrects-hope-room-temperature-superconductivity">Science</a>:</p><blockquote><p>To solve the riddle, the U of R team “should do everything they can to help other groups reproduce it,” says Mikhail Eremets, a physicist at the Max Planck Institute for Chemistry, whose team discovered the first hydride superconductor in 2015 but failed to replicate the CSH results. “If they will not it will be a disaster.” But this level of cooperation doesn’t appear to be in the cards. Dias says Unearthly Materials, a company he and Salamat founded, is trying to commercialize the new hydride. <b>“We are not going to distribute this material considering the proprietary nature of our process and the intellectual property rights that exist,” </b>Dias said via email.</p></blockquote><blockquote><p>Other physicists aren’t pleased. “It’s a completely unscientific behavior,” Boeri says. Hamlin says he won’t commit a student to replicating the work unless the U of R group shares samples and raw data. Salamat says the raw data are available online. As for sharing samples, the paper provides a detailed recipe, he says. “People can go ahead and make it for themselves.” [emphasis added]</p></blockquote><p>It's quite disappointing that they are unwilling to share the actual material, as that would silence most if not all of the controversy and let the discovery gain the prominence it deserves. Personally, I don't understand the difference between sharing the material for verification purposes versus sharing a detailed recipe that will allow for exact reproduction. This would be concerning regardless of the past history of the group. We've also seen this exact response from this group before: in 2020, when their last claimed room-temperature superconductor fell apart. It took a bit of digging, but I found Hirsch's original pre-print "Anatomy of a Probable Scientific Fraud". In it, he attaches emails he sent to Dias' team asking for access to their raw data, in order to help verify their results. </p><p><a href="https://jorge.physics.ucsd.edu/abstracts/pre-proof.pdf">UCSD</a>:</p><blockquote><p>It is also relevant to this story that independently Dr. Evgueni F. Talantsev had requested resistivity raw data as well as a a time track record for each measurement from Dias directly and through Nature editor Dr. Luke Fleet on October 21, 2020 [25] and again directly and through Nature editor Dr. Roedel on or about November 10. On November 16, Dias responded:</p></blockquote><p></p><blockquote><i>Dear Dr. Talantsev, We acknowledge your request for data relating to our recent Nature article entitled “Room temperature Superconductivity on carbonaceous sulfur hydrides”. We have discussed the request with counsel and unfortunately, <b>we are not able to provide you with the data for a number of reasons</b>, including the following. <b>The data may contain patentable inventions for which patent applications have not been updated or filed</b>. We have been advised that disclosure of the data may impair our ability to file patent applications in the future. <b>We cannot anticipate when we may have the authorization to share the data</b>. Regards, Ranga</i></blockquote><p></p><p>This is the same justification they are using today to deny other researchers access to the material, for verification. As a reminder, the "patentable inventions" they used to justify the lack of transparency ended up falling through, as even their own analysis was unable to reproduce them:</p><p><a href="https://www.nytimes.com/2023/03/08/science/room-temperature-superconductor-ranga-dias.html">New York Times</a>:</p><blockquote><p>A preprint redoing measurements of the carbon-sulfur-hydrogen material from the retracted 2020 paper is now circulating, but even that raises questions. “They’re significantly different from the original measurements,” Dr. Strobel said. “One could argue they haven’t even reproduced results themselves.”</p></blockquote><p><a href="https://www.nytimes.com/2023/03/08/science/room-temperature-superconductor-ranga-dias.html">Scientific American</a>:</p><blockquote><p>Hamlin went on to analyze a paper that Dias and Salamat published in Physical Review Letters (PRL) in 2021 in which they and their colleagues measured another hydride called manganese sulfide. Hamlin noted similarities between the electrical resistance data in the 2021 paper and those in Dias’s 2013 Ph.D. thesis, which had involved a completely different superconducting material. He shared these concerns with the journal and the paper’s authors. Salamat has since responded, suggesting that even though the two data sets may appear similar, the resemblance is not indicative of copied data. “We’ve shown that if you just overlay other people’s data qualitatively, a lot of things look the same,” he says. “This is a very unfair approach.”</p></blockquote><blockquote><p>This did not satisfy at least one of Salamat’s co-authors on the PRL paper: Simon A. J. Kimber, a former researcher, was disturbed to hear about the potential problem with the data and agrees with Hamlin’s conclusions. “I’ve been at this game for a long time, and I couldn’t think of a single reasonable explanation as to why those data sets should overlap like that,” he says. “I replied to everybody, to PRL’s editors, and said, ‘I think this should be retracted. I can’t think of any logical reason why this should be—retract, retract, retract.’” </p></blockquote><p><a href="https://www.nytimes.com/2023/03/08/science/room-temperature-superconductor-ranga-dias.html">New York Times</a>:</p><blockquote><p>However, the “if” part of that sentiment swirls around Dr. Dias, who has been dogged by doubts and criticism, and even accusations by a few scientists that he has fabricated some of his data. The results of the 2020 Nature paper have yet to be reproduced by other research groups, and critics say that Dr. Dias has been slow to let others examine his data or perform independent analyses of his superconductors.</p></blockquote><blockquote><p>The editors of Nature retracted the earlier paper last year over the objections of Dr. Dias and the other authors.</p></blockquote><blockquote><p>“I’ve lost some trust in what’s coming from that group,” said James Hamlin, a professor of physics at the University of Florida.</p></blockquote><blockquote><p>Dr. Dias’s main antagonist is Jorge Hirsch, a theoretical physicist at the University of California, San Diego...The plot in the paper seemed too neat, and the scientists did not explain how they had subtracted out background effects in the plot. When Dr. Dias released the underlying raw data, Dr. Hirsch said, his analysis indicated that it had been generated by a mathematical formula and could not be actually measured in an experiment. </p></blockquote><p>I found this passage later in the article interesting (though admittedly not particularly relevant):</p><blockquote><p>Dr. Hamlin was also disturbed when he found that several passages from his doctoral thesis, written in 2007, had appeared, word for word, in Dr. Dias’s dissertation...Of the copying of text from Dr. Hamlin’s doctoral thesis, Dr. Dias said he should have included citations. “It was my mistake,” Dr. Dias said.</p></blockquote><p>Generally scientific writing is paraphrased for citation, not copied exactly. Even self-plagiarism is extremely discouraged, so I can't imagine any train of thought that would lead to actually copying someone else's work word-for-word in an original thesis. A citation arguably wouldn't have made that okay.</p><p>It is important to note that while Hirsch is not the only scientist to point out issues with the results (past and present) from Dias' team, he may have a bias as Dias' results would support a theory that he is somewhat infamous for opposing:</p><p><a href="https://www.science.org/content/article/breakthrough-or-bust-claim-room-temperature-superconductivity-draws-fire">Science</a>:</p><blockquote><p>Ranga Dias, an applied physicist at the University of Rochester, who with his colleagues made the room-temperature superconductivity claim, rejects Hirsch’s allegations. He asserts that Hirsch isn’t an expert in high-pressure physics and that he has a history of claiming that the Nobel Prize–winning “BCS theory” underlying superconductivity is incorrect. Dias says Hirsch relentlessly badgers superconductivity researchers. “Hirsch is a troll,” Dias says. “We are not going to feed this troll” by providing the data. </p></blockquote><blockquote><p>Dias and others say they don’t trust Hirsch to appraise the data fairly. “Unfortunately, sometimes he is not objective,” says Vasily Minkov, a chemist at the Max Planck Institute for Chemistry who synthesizes hydride superconductors and says Hirsch has cherry-picked data from the Max Planck experiments for his critiques.</p></blockquote><p>This back-and-forth has resulted in moderation as the claims from each about the other have grown less and less professional.</p><p><a href="https://www.science.org/content/article/preprint-server-removes-inflammatory-papers-superconductor-controversy">Science</a>: </p><blockquote><p>A debate over claims of room temperature superconductivity has now boiled over into the realm of scientific publishing. Administrators of arXiv, the widely used physics preprint server, recently removed or refused to post several papers from the opposing sides, saying their manuscripts include inflammatory content and unprofessional language. ArXiv has also banned one of the authors, Jorge Hirsch, a theoretical physicist at the University of California, San Diego (UCSD), from posting papers for 6 months.</p></blockquote><p>While Hirsch may have been somewhat abrasive (Daniel Arovas amusingly referred to the exchange as "distasteful accusations") he was far from the only person who shared the concerns--including some of the authors of the 2020 paper.</p><blockquote><p>One of [the 2009] study’s authors, James Hamlin, a physicist now at the University of Florida, who participated in the europium study as a graduate student, recently determined, he says, that “there are alterations to the data.” The study’s senior author, James Schilling, an emeritus physicist at Washington University in St. Louis, says he shares that concern. Now, some of the co-authors are redoing the measurements, and if they don’t hold up, the team will retract the [2020] paper, Hamlin says. </p></blockquote><p>The paper was eventually retracted. </p><p><a href="https://www.science.org/content/article/breakthrough-or-bust-claim-room-temperature-superconductivity-draws-fire">Science</a>:</p><blockquote><p>Given the questions, several scientists say Dias should make his data public. “I am unhappy that Dias is supposedly not cooperating with researchers who are questioning his data,” says Marvin Cohen, a theoretical physicist at UC Berkeley. Schilling is blunt: “I told Dias to give [Hirsch] the raw data, for heaven’s sake.”</p></blockquote><blockquote><p>In his email [responding to Hirsch's request for the raw data], Dias wrote, “Given that you have an active comment on our work, we consider such a request would not be reasonable.” Frustrated, Hirsch requested the data from Nature and the National Science Foundation (NSF), which funded the work. On 30 August, Nature appended an editor’s note to Dias’s paper saying: “The editors of Nature have been alerted to undeclared access restrictions relating to the data behind this paper. We are working with the authors to correct the data availability statement.” NSF and the University of Rochester both tell Science they cannot comment on possible investigative matters.</p></blockquote><p>A theoretical analysis on the theoretical feasibility of superconductivity in lutetium hydride was published. The results add an interesting dimension to the controversy.</p><p><a href="https://pubs.aip.org/aip/mre/article/8/3/038402/2887777/First-principles-study-on-the-conventional">AIP</a>:</p><blockquote><p>Recently, room-temperature superconductivity has been reported in a nitrogen-doped lutetium hydride at near-ambient pressure [Dasenbrock-Gammon et al., Nature 615, 244 (2023)]. </p></blockquote><blockquote><p>Here, we systematically study the phase diagram of Lu–N–H at 1 GPa using first-principles calculations, and we do not find any thermodynamically stable ternary compounds.</p></blockquote><blockquote><p>Our theoretical results show that the Tc values of N-doped LuH3 estimated using the Allen–Dynes-modified McMillan equation are much lower than room temperature.</p></blockquote><p>The conclusion seems to be that, based on existing theory, it is not possible to form a stable combination of lutetium, nitrogen, and hydrogen. </p><blockquote><p>Notably, all predicted potential ternary compounds lie above the convex hull at 1 GPa. Thus, no ternary Lu–N–H compounds can remain thermodynamically stable at this pressure, which is consistent with the main results of Xie et al.26</p></blockquote><p>And even if it were, it seems it would superconduct at far lower than room temperature, in line with existing experiments. </p><blockquote><p>Our simulations show that the lowest T_c is 4 K for LuH3 without doping. In addition, T_c increases with increasing N-doping concentration; thus, doping N atoms into LuH3 will increase T_c. However, the highest T_c in this VCA calculation is 22 K, obtained with 1% N-doping at 30 GPa, which is much lower than room temperature.</p></blockquote><p>It's worth noting that 30 GPa is about 300 kbar, which is 30 times higher than the pressures reported in Dias et al. (2023). Further investigation is needed, but it seems theoretically unlikely to produce a material like the doped LuNH3 at the reported temperatures and pressures. Certainly even less likely for it to superconduct at room temperatures. This is based on existing theory, so the possibility remains that Dias et al. have discovered an exciting new effect that will require more advanced models to explain. <br /></p><p>I've been posting occasional updates as I've followed this and other
superconductor stories with great interest. This one took an interesting
turn with a series of retractions from <i>Nature</i>.</p><p><i><a href="https://www.nature.com/articles/s41586-020-2801-z">Nature</a>: </i></p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">RETRACTED ARTICLE: Room-temperature superconductivity in a carbonaceous sulfur hydride</p><p style="text-align: left;">The
editors of Nature have been alerted to concerns regarding the manner in
which the data in this paper have been processed and interpreted.
Nature is working with the authors to investigate these concerns and
establish what (if any) impact they will have on the paper’s results and
conclusions. In the meantime, readers are advised to use caution when
using results reported therein. </p></blockquote><p style="text-align: left;"></p><p style="text-align: left;">This is their second retracted paper.<br /></p><p><i><a href="https://www.nature.com/articles/d41586-023-03398-4">Nature News</a>:</i></p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Nature
has retracted a controversial paper claiming the discovery of a
superconductor — a material that carries electrical currents with zero
resistance — capable of operating at room temperature and relatively low
pressure.</p><p style="text-align: left;"> “They have expressed the view as researchers who contributed to the
work that the published paper does not accurately reflect the provenance
of the investigated materials, the experimental measurements undertaken
and the data-processing protocols applied,” [the retraction report] says, adding that these
co-authors “have concluded that these issues undermine the integrity of
the published paper”.</p><p style="text-align: left;">“It
is at this point hardly surprising that the team of Dias and Salamat
has a third high-profile paper being retracted,” says Paul Canfield, a
physicist at Iowa State University in Ames and at Ames National
Laboratory. Many physicists had seen the Nature retraction as inevitable
after the other two, and especially since The Wall Street Journal and
Science reported in September that 8 of the 11 authors of the paper —
including Salamat — had requested it in a letter to the journal.</p><p style="text-align: left;">One
lab says it has partially reproduced Dias and Salamat’s results using a
sample provided by the Rochester team. But many others, which tried
creating their own samples and running tests, could not. And in the
meantime, other causes for concern have arisen. An investigation
launched by Physical Review Letters before it retracted its paper by
Dias and Salamat found “apparent data fabrication”.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><a href="https://www.science.org/content/article/another-retraction-looms-embattled-physicist-behind-blockbuster-superconductivity">Science.org</a>:</p><p style="text-align: left;"><i> </i></p><blockquote><p style="text-align: left;">Facing
a mutiny by his co-authors, Ranga Dias, the University of Rochester (U
of R) physicist embroiled in controversy over his superconductivity
research and allegations of scientific misconduct, is set to have a
third paper retracted.</p><p style="text-align: left;">If
the paper is retracted, it will follow retractions of two other
superconducting claims from Dias’s teams: one last month from Physical
Review Letters (PRL), and one in September 2022 of a different Nature
paper.</p><p style="text-align: left;">In
a 14 September email to the co-authors, Nature Senior Editor Tobias
Rödel says a postpublication review revealed issues that are “mostly
unaddressed.” Rödel added, “We are in absolute agreement with your
request that the paper be retracted.”</p><p style="text-align: left;">Questions
about the March paper’s results appeared online immediately after its
publication. On 2 May, two researchers submitted an anonymous critique
of the paper to Nature. These researchers disclosed their identities to
Science: They are James Hamlin, a high-pressure experimentalist at the
University of Florida, and Brad Ramshaw, an expert in superconductivity
at Cornell University.</p><p style="text-align: left;">In
their letter to Nature the co-authors allege they had raised concerns
about the study prior to publication, but that Dias dismissed them. </p><p style="text-align: left;">After
seeing the postpublication review, the co-authors used their access to
the raw data to corroborate Hamlin and Ramshaw’s concerns about the
zero-resistance measurement. </p></blockquote><p style="text-align: left;"></p><p style="text-align: left;"><a href="https://www.nytimes.com/2023/08/15/science/retraction-ranga-dias-rochester.html">New York Times</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">A prominent physics journal on Tuesday retracted a materials science paper that has garnered scrutiny. </p><p style="text-align: left;">The
retracted paper did not involve superconductivity, but it added to
accusations against Dr. Dias of research misconduct, including the
fabrication and falsification of data. </p><p style="text-align: left;">Nine
of the 10 authors of the paper, which was published in Physical Review
Letters, agreed to the retraction. Dr. Dias was the lone holdout, and he
has maintained that the paper accurately portrays the research
findings. However, he said on Tuesday that his collaborators, working in
the laboratory of Ashkan Salamat, a professor of physics at the
University of Nevada, Las Vegas, introduced errors when producing charts
of the data using Adobe Illustrator, software not typically used to
make scientific charts.</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;">This took me pretty massively by surprise. I can only speak from my own personal experience, but nobody--I mean<i> nobody</i>--makes
charts by hand anymore. We've had programmatic tools to ensure
precision for literally decades. Most plots these days are done using
scripts that access plotting libraries; for example, I make my plots in
Python using <a href="https://matplotlib.org/">matplotlib</a>.
I just can't understand what part of the process one would use Adobe
Illustrator of all things for--I wish Dr. Dias had elaborated on this
more. The problems identified were found in the background subtraction
procedure and potentially claims of duplicated data; without commenting
on the truth of these allegations, how could one "accidentally" do these
things or something similar in Adobe Illustrator of all things? And why
would this affect the raw data files that were shared with the
investigators and coauthors, which ultimately were found to be flawed as
well? </p><p style="text-align: left;"><a href="https://www.nature.com/articles/d41586-023-02401-2">Nature News</a>:<br /></p><p style="text-align: left;"></p><blockquote>As part of the investigation, co-author Ashkan Salamat, a physicist at
the University of Nevada, Las Vegas, and a long-time collaborator of
Dias, supplied what he claimed was raw data used to create figures in
the <i>PRL</i> paper. But all four investigators found that the data Salamat provided did not match the figures in the paper.</blockquote><p></p><p style="text-align: left;">Ignoring
everything else, the raw data didn't match the figures. But Dr. Dias
necessarily needs the figures to be correct if his superconductor is
legitimate--the figures showed the proof. </p><p style="text-align: left;"><a href="https://www.sciencenews.org/article/room-temperature-superconductor-retracted-ranga-dias">Science News</a>:</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">A
stunning claim of a room-temperature superconductor that grabbed
headlines has fizzled. The paper was retracted November 7 from the
journal Nature, making for a trio of high-profile retractions for
physicist Ranga Dias of the University of Rochester.</p><p style="text-align: left;">The
retraction is no surprise to the scientific community, many of whom had
expressed hefty skepticism about Dias’ work, following the earlier
retractions and many other researchers’ failures to reproduce Dias’
results. </p><p style="text-align: left;">Compared
to the previous retractions, “this is much more worrying,” Boeri says.
“This is not just somebody who is doing some honest mistakes.”</p></blockquote><p style="text-align: left;">Ranga Dias (via <a href="https://twitter.com/rdias495/status/1748168980353691998">Twitter</a>):</p><p style="text-align: left;"></p><blockquote><p style="text-align: left;">Meissner effect on N- doped Lutetium Hydride! </p><p style="text-align: left;">[mic drop gif] <br /></p><p style="text-align: left;">The Meissner effect is considered the definitive proof of superconductivity!</p></blockquote><p style="text-align: left;"></p><p style="text-align: left;">I
look forward to the submission of that result. At the end of the day,
everyone only benefits if Dr. Dias is correct and room-temperature
superconductivity is achieved. <br /></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-28915999594525706112023-03-14T19:42:00.003-07:002023-03-14T19:42:22.156-07:00Photometry and spectroscopy of the Type Icn supernova 2021ckj: The diverse properties of the ejecta and circumstellar matter of Type Icn SNe<p><a href="https://arxiv.org/abs/2303.07721">arXiv</a>:</p><blockquote><p>Spectral modeling of SN 2021ckj reveals that its composition is dominated by oxygen, carbon and iron group elements, and the photospheric velocity at peak is ~10000 km/s. From the light curve (LC) modeling applied to SNe 2021ckj, 2019hgp, and 2021csp, we find that the ejecta and CSM properties of Type Icn SNe are diverse.</p></blockquote><blockquote><p>The similarity of the emission components of these lines implies that the emitting regions of SNe 2021ckj and 2021csp have similar ionization states, and thus suggests that they have similar properties of the ejecta and CSM, which is inferred also from the LC modeling. Taking into account the difference in the strength of the absorption features, this heterogeneity may be attributed to viewing angle effects in otherwise common aspherical ejecta.</p></blockquote><p><br /></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-6328685254190645232023-03-14T19:39:00.003-07:002023-05-18T00:00:20.228-07:00The core degenerate scenario for the type Ia supernova SN 2020eyj<p><a href="https://arxiv.org/abs/2211.04353">arXiv</a>:</p><blockquote><p>We argue that the core degenerate (CD) scenario of type Ia supernovae (SNe Ia) can explain the compact helium-rich circumstellar material (CSM) of SN 2020eyj...We follow the evolution of two stellar models with initial masses of 5Mo and 7Mo to their asymptotic giant branch phase when they are supposed to engulf the WD companion. We find that there is a sufficiently massive CO core to merge with the WD in the frame of the CD scenario as well as a massive helium-rich layer, ~0.3-1Mo, to account for the helium-rich CSM of SN 2020eyj.</p></blockquote><blockquote><p>The motivation of our study is the new observations of SN 2020eyj, a SN Ia-CSM with a helium-rich CSM (Kool et al. 2022) and the need to consider all SN Ia scenarios when analysing observations, as the long list of recent papers that study different scenarios suggests.</p></blockquote><blockquote><p>Building on earlier papers that argue for the CD scenario for SNe Ia-CSM (section 2) we propose the CD scenario also for SN 2020eyj, but we consider a new channel that accounts for the helium-rich CSM (section 3).</p></blockquote><p><br /></p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0tag:blogger.com,1999:blog-7986907640848514702.post-85311013162375851272023-03-07T21:45:00.000-08:002023-03-07T21:45:46.491-08:00LCO Data Confirm the Success of NASA’s DART Mission<p><a href="https://lco.global/news/lco-data-confirm-the-success-of-nasas-dart-mission/">Las Cumbres Observatory</a>: </p><blockquote><p>The NASA Double Asteroid Redirection Test mission — the first test mission for NASA’s Planetary Defense Coordination Office — launched a spacecraft in November of 2021 with the aim to crash into the binary near-Earth asteroid system Didymos. </p></blockquote><blockquote><p>LCO scientists Dr. Tim Lister, Dr. Joey Chatelain, and Dr. Edward Gomez are coauthors on this paper. Dr. Lister heads the LCO group studying Near-Earth Objects, which employed data taken from LCO 1-m telescopes in South Africa and Chile for analysis. The data from the LCO telescopes, along with two others in Chile and planetary radar observations from Goldstone, CA, were used to measure the new period of Dimorphos after the DART impact. </p></blockquote><blockquote><p>Dr. Tim Lister is pleased that LCO played a vital role in the DART mission, “It’s been a great privilege to be involved with and contribute to such an important mission for planetary defense. Having LCO telescopes in both Chile and South Africa allowed us to compare with other telescopes in Chile and also capture parts of Dimorphos’s orbit that other telescopes couldn’t. LCO’s extensive telescope network in the Southern Hemisphere was important in being able to measure the period change so soon after the impact.”</p></blockquote><p>DART is a really exciting project--it's really fun to watch these results unfold from a front row seat. Tim, Edward and Joey are awesome scientists, and Tim's talks about DART are phenomenal. I had the privilege and misfortune of speaking following a DART talk he gave at our local <a href="https://lco.global/aot/november-30-2022/">Astronomy on Tap</a>; very tough act to follow. </p>Joseph Farahhttp://www.blogger.com/profile/02015681266731807825noreply@blogger.com0