Science

We have long suspected that music has restorative qualities, but Daniel Levitin is now providing rigorous evidence that it can help treat many conditions, including depression, speech loss and Alzheimer's

The long-awaited detection of gravitational waves has opened up a whole new world of astronomy. One of the key efforts is now to tie signals across multiple domains – for example, a gravitational wave and the associated electromagnetic radiation created by that same event, such as a black hole merger or a gamma-ray burst. We’ll need new equipment to detect such “multimodal” signals, especially electromagnetic ones. One such project is the Black Hole Coded Aperture Telescope (BlackCAT), which will be launched early this year by a team led by researchers at Penn State. 

BlackCAT is designed to replace aging equipment already capturing high energy emissions, such as X-rays, in space. Swift and Fermi, two leading such telescopes, will be at least 10 years over their expected design lifetimes when a series of new gravitational wave detectors come online. Their aging capabilities limit their usefulness in finding the electromagnetic analog of the once-weekly gravitational wave events that those new detectors hope to find.

Enter BlackCAT, a mission concept initially proposed in 2019. It is designed as a 6U Cubesat with one particular detector for “soft” X-ray detection. Soft X-rays are the lower-energy versions of “hard” X-rays typically used in X-ray astronomy. However, they have the added advantage of being easier to detect. They are also easier to isolate to a specific location in the sky, which is essential when mapping a particular EM signal to the source of a gravitational wave event.

Fraser discusses the shutdown of Chandra – a previous X-Ray telescope.

To detect those lower-energy X-rays, BlackCAT has two tools in its toolbox—an array of CMOS X-ray cameras and a coded mask imager. The array of cameras, which includes four separate cameras, is called “Speedster-EXD.” It is specifically designed to react quickly to signals but only measures about 2.2 cm2 in size. However, it is still capable of producing a 550×550 pixel image. These cameras have been tested on the ground and have shown sensitivity to the wavelengths of X-rays the mission is designed for.

The coded aperture mask that helps give BlackCAT its name is a tool used to provide a wide field of view for the sensor without needing a focal point – which is hard to design for X-rays that ignore typical focusing devices like lenses and mirrors. Instead, the aperture is a plate designed with a pattern of “open” and “closed” areas that produce shadows on the detector. A computer program can then recreate the original image based on the pattern of shadows that fall across the detector.

This combination of the broad field of view with a highly sensitive X-ray detector seemed right up NASA’s alley, as they funded the project in 2021 to the tune of $5.8M. The detector will interface with an off-the-shelf 6U CubeSat provided by Clyde Space, which includes standardized power, control, and attitude adjustment systems – acting like a platform for the detector. 

Fraser discusses GRBs, one of the things BlackCAT is designed to detect.

PSU’s research team is likely in the final touches of integrating with a launch vehicle, and the plan is to launch BlackCAT early this year. When it gets up there, it can open up a whole new world in X-ray astronomy for a surprisingly low cost. Hopefully, it will show how much can be accomplished by simple, expensive, but very focused CubeSat missions.

Learn More:
Chattopadhyay et al – BlackCAT CubeSat: A Soft X-ray Sky Monitor, Transient Finder, and Burst Detector for High-energy and Multimessenger Astrophysics
Colosimo et al – Current status of the BlackCAT CubeSat
UT – SpIRIT CubeSat Demonstrates a Operational Gamma and X-Ray Detector
UT – A Collection of New Images Reveal X-Rays Across the Universe

Lead Image:
Models of the coded aperture (left) and the BlackCAT Cubesat as a whole (right.
Credit – Colosimo et al.

The post A CubeSat Mission Will Detect X-rays from GRBs and Black-Hole Mergers appeared first on Universe Today.

The tale of Fermat's last theorem took hundreds of years and included tantalising twists, disappointing errors and a contribution from the most unlikely cartoon mathematician imaginable

There are two items of interest in the Big KerFFRFle, the dispute in which the Freedom from Religion Foundation appears to be melting down over an episode in which they removed my post on gender from their website.

The first is an account of the fracas by Yontat Shimron in the Religion News Service (RNS). The piece is pretty objective but has a few glitches. Click below to read it, or find it archived here. The most interesting part is its confirmatio—heretofore only a rumor—that the FFRF has dissolved its entire Honorary Board, the board of 18 honorees from which Richard Dawkins, Stephen Pinker, and I resigned.

I’d heard rumors that the other 15 members of the Honorary Board were also vanished, even though you can still see them at this link, (archived here) found by Googling “FFRF honorary board”. Curiously, you get two links when you Google those words, with the other one, here,  showing only one name, Jeremiah Camara.  But the reporter of the piece below verified that the entire Honorary Board is gone—defunct, sleeping with the fishes and singing with the Choir Invisible.

Click to read or, if the article disappears or changes, the version posted this morning is archived here.

The part that I found most bizarre, but conforming to rumors I’ve heard, is this (also noted in the headline):

The nation’s largest freethought organization has dissolved its honorary board after three of its prominent members resigned in an ideological battle over transgender issues.

And that’s all it said, but if a reporter noted it, she must have had information. I contacted Yonat Shimron, who verified that yes, the honorary board of the FFRF has been dissolved, that this was confirmed to her by one of the co-Presidents of the FFRF, and that it was done at the behest of the FFRF’s governing board.

The conclusion, of course, is that the FFRF does not WANT an honorary board at all. Why? The only conclusion I can reach is that other honorary-board members could, in the future, cause “trouble” in the way that the three of us did, publicly criticizing the organization for its mission creep and adherence to woke gender ideology.  Ditching the other 15 (I hope they’ve been told!) is an often-seen aspect of wokeness: any index of merit that conflicts with “progressive” ideology must be effaced. (Similarly, many American colleges have dropped requirements for applicants to submit standardized test scores, like those from the SAT and ACT.)  It seems that the FFRF doesn’t want to take a chance with people on the honorary board publicly espousing the “wrong ideology.”

A tweet from Colin Wright:

I have internal confirmation that the @FFRF has indeed dissolved their Honorary Board following the public resignations of Dawkins, Pinker, and Coyne.

When your organization has abandoned its core principled, maintaining a Board of principled intellectuals becomes a liability. https://t.co/E1P0OtIoLX

— Colin Wright (@SwipeWright) January 6, 2025

There are a couple of things I am not keen on about the piece, but in general it’s objective and accurate. I do think the sub-headline overly dramatizes my claim that transwomen are more sexually predatory than “other women” (I of course meant biological women). That was certainly not the main point of my piece, which was the definition of “woman”.   But the data certainly support that claim, which shows beyond doubt that, with respect to criminal sexual behavior, trans women are not women. Anyway, this is a quibble; authors and editors have the right to emphasize what they want.

My other beef, however, is more important, as it’s a matter of accuracy. The RNS article says this. I’ve put the contentious bits in bold:

The post, which drew intense backlash, was taken down on Dec. 28, one day after it was published, prompting Coyne, Dawkins and Pinker to resign from the foundation. That led the foundation to dissolve the 14- member honorary board.

The flap offers a peek at a roiling controversy among a select group of New Atheists who have expressed views that are anti-transgender and more generally “anti-woke.” It is a position taken by another atheist group, the Center for Inquiry. But it is also hotly contested by most in the nonbeliever community. In 2021, the American Humanist Association withdrew its “Humanist of the Year” award from Dawkins over his anti-trans comments.

In an interview with RNS, Annie Laurie Gaylor, the co-president of the Freedom From Religion Foundation, took responsibility for publishing and then removing Coyne’s article.

First, I don’t know any New atheist who has expressed views that are “anti-transgender”, only discussing that the rights of transgender people might rarely conflict with the rights of other groups (viz., sports) and need to be adjudicated.  The article makes New Atheists look like people who want to erase trans folks. That ain’t true. (Yes, I suppose you can find a handful of “New Atheist” who are truly bent on curtailing all the rights of transgender people, but they are surely in the minority.)

But the bit about Dawkins is grossly distorted. Below are the purported “anti-trans” comments that Richard tweeted, comments made the AHA withdraw its award, committing a reprehensible act.  As Richard has explained, he was merely posing a question for discussion, a question first raised in 2017 by philosopher Rebecca Tuvel in a published paper (“In defense of transracialism“) that concluded that there was no substantive ethical difference between asking people to accept your non-natal gender and asking them to accept your non-natal “race.”

Tuvel’s paper caused a huge controversy because some people didn’t like the race aspect, though I read Tuvel’s paper and agree with her. Still, the editor of the journal resigned, the journal (Hypatia) apologized, and many scholars called for the paper’s removal. Tuvel, a brave soul, stuck to her guns and the paper is still up. And the question is still worth debating, as Richard noted. Why is there a difference between transgenderism and transracialism?  Isn’t that something to chew on?

Richard noted that he was simply framing the question as one to ponder, as he would with questions posed to his Oxford students to discuss in their weekly essay. You can see his tweet below, and it is certainly not “anti-trans”!  The RNS really should change that, as it borders on defamation.

In another piece, secularist, humanist, and writer Ed Buckner wrote a piece on the kerFFRFle on his Substack site. You can access it by clicking below. It is generally favorable toward the views of Richard, Steve, and I, as well as toward our resignations, but makes one point that I want to emphasize:

Buckner refers to an online essay criticizing my now-defunct essay on the FFRF site (archived here), and to an essay by Aaron Rabinowitz on the Unfriendly Atheist site, to which I’ve added the link:

To turn now more specifically to Aaron Rabinowitz’s essay on Friendly Atheist (link below if you missed it), he criticized Jerry Coyne for allegedly pretending to expertise as an ethicist, for overstepping his status as a pre-eminent biologist. But I reread Coyne’s essay with care and nowhere did he state or imply that he’s an ethicist, expert or otherwise.

And Buckner has rewritten part of what I wrote to make it conform with his own ethical beliefs. In fact I agree with Buckner’s writing, which expresses my real views, views I should expanded on in the original FFRF piece:

Coyne does offer some opinions that are related to ethics, of course.

For example,

Transgender women, for example, should not compete athletically against biological women; should not serve as rape counselors and workers in battered women’s shelters; or, if convicted of a crime, should not be placed in a women’s prison.

My own “ethical” opinion is close to Coyne’s. I would probably—but only after I studied the matter more carefully, including discussions with rape counselors and probably even with women who’ve been victims of rape or of women-batterers, modify some of what Coyne wrote slightly to say:

Neither men or women, cis- or trans-gendered, should serve as rape counselors and as workers in battered women’s shelters, unless the counselors or others working there pass a background check; even then, no one should so serve unless the clients are aware of and accept the status of the counselors/workers.

I can imagine circumstances where there might be an advantage to victims of having a man or a trans woman on hand, but the rights, needs, and wants of the victims, even if sometimes irrational, should be paramount.

I think the second version, expressing Buckner’s views, is better than what I wrote, and it does summarize views I already held (but failed to express). While I still think that at present tranwomen should not compete against biological women in sports, and shouldn’t really be running battered women’s shelters, they should not be completely barred from that job nor from acting as rape counselors—so long as (as Buckner writes), they undergo a background check and the women residents of shelters or women being counseled for rape or sexual assault are made aware that the counselor is a trans woman (a biological man) and are okay with that. This view will, of course still be seen as “transphobic” by some extremists, but there’s a very good case for holding this view in light of the rights of biological women. This involves a conflict between two groups’ “rights”, and in the interests of fairness and the needs of biological women, I come down against sports participation of transwomen and cast a very cold eye on the other two issues.

Buckner’s conclusion (bolding is Buckner’s)

Serious freethinking, requires, in my view, expressing views and understanding and accepting that your views may not be accepted as correct by everyone. Real disagreement can occur, and this should not lead FFRF or anyone else to declare, as it did in (unwisely) removing Coyne’s reply to [Kat] Grant,

We regret any distress caused by this post and are committed to ensuring it doesn’t happen again.

That’s a terrible outcome. Of course FFRF should not publish a hateful, bigoted essay (Coyne’s wasn’t) and then remove it—it should instead post essays that disagree with other essays and promise to keep posting words from people who think freely enough to not always toe anyone’s dogmatic party line—and to say so.

I posted a comment agreeing with Buckner’s rewriting of my views on shelters and counselors, but Richard also posted an excellent related comment (click to enlarge if you’re myopic or reading on a phone):

The fallout from this affair is not quite over, but I think it does constitute a twofold lesson. First, the ideology of Leftist humanists and atheists such as Richard, Steve, and I will sometimes conflict with the ideology of other Leftist humanists and atheists, particularly when it comes to wokeness. We are not a homogenous group.

Second, it is not right for organizations that promote freethought and discussion to censor people whose ideology conflicts with their own, and by “censoring” I mean first allowing the heterodox person to publish material on the organization’s website but subsequently removing it because the publication was “a mistake” that caused “distress”. That is nonsensical behavior, and it does the FFRF no credit. (I hasten to add that I always admired, and still admire, the FFRF’s initiatives to keep religion out of government and educate people about nontheism.)

Anyway, read Buckner’s piece; there’s a lot more in it than I’ve described above.

Industrial waste can make rudimentary batteries. That's likely no good in electric cars etc, but could be ideal for stashing away vast surpluses of renewable power.

When it comes to exploring our planetary neighbours, Mars tends to get a lot of the attention. For one thing its easier to explore as the environment is far less hostile than other planets but it also offers the tantalising possibility of finding evidence of primitive life, past or present! Venus however is still a fascinating world and perhaps one that gives us a glimpse into our future if we don’t do something to check global warming. A team of scientists are proposing an official Venus Exploration Program for NASA similar to the existing Mars program. 

Venus is the second planet from the Sun and has often been referred to as Earth’s twin! This is chiefly due to its similar size and composition however, despite these similarities, Venus and Earth are worlds apart! Its thick carbon dioxide atmosphere traps heat causing the surface temperature to rocket to just under 500 degrees. It’s surface is hidden beneath thick clouds of sulfuric acid, and its atmospheric pressure is about 90 times that of Earth’s. There is no doubt, Venus is not somewhere you would want to go on your cosmic holidays. Despite all of this, and despite the challenges, Venus does remain a fascinating place to study.

Venus

Following a recommendation that NASA should develop scientific exploration strategies as it has for Mars; VEXAG, the Venus Exploration Analysis Group, was established. This community-driven initiative has been established by NASA to facilitate and provide scientific and mission support and planning to the exploration of one of our nearest planetary neighbours. VEXAG is composed of researchers, planners and engineers whose goal is to assess various scientific objectives to inform NASAs future mission to Venus. 

Radar image of Venus created by the Solar System Visualization project and the Magellan science team at the JPL Multimission Image Processing Laboratory. This is a single frame from a video released at the October 29, 1991, JPL news conference. (Credit: NASA/JPL)

The VEXAG mission to develop a new Venus exploration strategy by reflecting upon the 2021 selections of the VERITAS (an orbiter designed to reveal how the paths of Venus and Earth diverged, and how Venus lost its potential as a habitable world,) DAVINCI (to explore whether the inhospitable surface of Venus could once have been a twin of Earth,) and EnVision (studying atmosphere of Venus) missions. 

Illustration of NASA’s DAVINCI probe falling to the surface of Venus. (Credit: NASA GSFC visualization by CI Labs Michael Lentz and others)

There are still lots of unanswered questions surrounding Venus from how it loses heat to  how geologically active it is and how has the atmosphere evolved over time. These and other questions are the focus of the exploration strategy and it is the VEXAG objective to look at the scientific, technological and programmatic advances required to address them. 

The report is comprehensive and offers a much needed assessment of the exploration of Venus. The existing slated and previously highlighted missions to Venus will likely launch during the early part of the next decade provide for an opportunity to address some of the outstanding questions. 

It will take some months before the measurements provide the much needed insight however additional missions are needed to address all of the remaining questions. It is now down to organisations like NASA and its international peers to take the next step to develop a new strategy for the exploration of Venus. 

Source : A New Strategy for the Exploration of Venus

The post Venus is Important. We Should Take its Exploration Seriously. appeared first on Universe Today.

Male flies have been genetically engineered to produce poisonous proteins in their seminal fluid, a technique that could be employed against pests and disease carriers

Whether AI can assist in cancer detection has been subject to much debate, but now a real-world test with almost 200 radiologists shows that the technology can improve success rates

In order to uncover the relationship between structure and function, researchers used microfluidic devices to study neuronal networks.

In order to uncover the relationship between structure and function, researchers used microfluidic devices to study neuronal networks.

Researchers have harnessed artificial intelligence to take a key step toward slashing the time and cost of designing new wireless chips and discovering new functionalities to meet expanding demands for better wireless speed and performance.

A new study has identified 11 genes that may hold the key to understanding the brain's response to these pervasive chemicals commonly found in everyday items.

Taking advantage of a cosmic 'double lens,' astronomers resolved more than 40 individual stars in a galaxy so far away its light dates back to when the universe was only half its present age.

Physicists have proposed a solution to a long-standing puzzle surrounding the GD-1 stellar stream, one of the most well-studied streams within the galactic halo of the Milky Way.

A formula can be used to predict what happens when a new species is introduced into an ecosystem -- whether it will establish itself in the community or fail to gain a foothold and die out.

I’ve used this fact a gazillion times; every atom in your body has been through the core of a star! The carbon in our bones formed through fusion like many other elements and was thrown out into space to seed the cosmos with the elements for life. A team of researchers have been exploring this journey, tracking a giant conveyor belt that surrounds the Galaxy and the results are surprising. 

Carbon is one of the fundamental elements inside our bodies. The first elements that appeared after the Universe formed 13.7 billion years ago was mostly hydrogen and a little helium.  The carbon in our bodies has been synthesised inside stars in a process known as nucleosynthesis. 

As stars evolve, they undergo a series of fusion reactions fusing hydrogen atoms into helium, then helium nuclei into carbon. Three helium-4 atoms combine to create an atom of carbon-12. Temperatures of around 100 million kelvin are needed for this process and, as it progresses, an outward pushing force known as the thermonuclear force is generated. During the main part of a stars life, this is balanced by the inward force of gravity. 

This is an artist’s concept of the early stages of the young star FU Orionis (FU Ori) outburst, surrounded by a disk of material. A team of astronomers has used the Hubble Space Telescope’s ultraviolet capabilities to learn more about the interaction between FU Ori’s stellar surface and the accretion disk that has been dumping gas onto the growing star for nearly 90 years. NASA-JPL, Caltech

At a point in the evolution of the star which is determined by its mass, the material that composes the star is ejected out into space through a planetary nebula or supernova explosion. Ultimately these heavier elements find their way to new stellar nurseries where the next generation of stars and even planets and life may form. 

This colorful web of wispy gas filaments is the Vela Supernova Remnant, an expanding nebula of cosmic debris left over from a massive star that exploded about 11,000 years ago. This image was taken with the Department of Energy-fabricated Dark Energy Camera (DECam), mounted on the US National Science Foundation’s Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab. The striking reds, yellows, and blues in this image were achieved through the use of three DECam filters that each collect a specific color of light. Separate images were taken in each filter and then stacked on top of each other to produce this high-resolution image that contains 1.3 gigapixels and showcases the intricate web-like filaments snaking throughout the expanding cloud of gas.

Scientists from the United States and Canada have shown in their latest research that the liberated carbon atoms don’t just drift aimlessly through space until they find their new home. Instead, their studies reveal that in galaxies like the Milky Way where star formation is still underway, the atoms take a less direct route. Giant currents known as the circumgalactic medium circle the galaxy and extend out into intergalactic space. The currents drag the newly ejected stellar material out and draw it back in to the interior of the galaxy where it forms new stars. 

The Milky Way. This image is constructed from data from the ESA’s Gaia mission that’s mapping over one billion of the galaxy’s stars. Image Credit: ESA/Gaia/DPAC

To reach this conclusion, the team used the Cosmic Origins Spectrograph on the Hubble Space Telescope. This instrument enabled the study of the ultraviolet radiation in detail from nine distant quasars. They explored how they were effected by circumgalactic medium of 11 other galaxies that had active star forming regions. The results showed the absorption of light by carbon. One galaxy showed carbon caught up in the current extending to a distance of nearly 400,000 light years. To put that into context that is around four times the diameter of our own Milky Way Galaxy! 

This image of NASA’s Hubble Space Telescope was taken on May 19, 2009 after deployment during Servicing Mission 4. NASA

It’s quite an eye opening discovery and certainly repaints the picture of stellar evolution. Instead of the gentle drifting through space of elements ejected from stars, the journey is far more tumultuous. As always though, more research is needed to fully understand the circumgalactic medium and to understand its impact on stellar formation. Not only will we get a better understanding of the lives of stars but how galaxies evolve too and why some host active star formation and others are stellar deserts. 

Source : The carbon in our bodies probably left the galaxy and came back on cosmic ‘conveyer belt’

The post You’re Made of Carbon that Took a Journey into Intergalactic Space appeared first on Universe Today.

A person in Louisiana who became severely ill with a bird flu virus known as H5N1 in December has passed away from the infection, marking the first known bird flu death in the US

Nature is filled with examples of extreme life (aka. extremophiles), which are so-called because they can withstand extreme conditions. These include organisms that can survive in extremely dry conditions, extreme temperatures, acidity, pressure, and even the vacuum of space. The study of these organisms not only helps scientists learn more about the kinds of environments life can survive (and even thrive) in. It also helps astrobiologists to speculate about possible life in the Universe. Perhaps the name “tardigrades” (aka. “water bears”) rings a bell, those little creatures that could survive in interstellar space?

Then you have Deinococcus radiodurans (D. radiodurans), which microbiologists call “Conan the Bacterium” due to its ability to tolerate the harshest conditions. This includes radiation doses thousands of times higher than what would kill a human, or any other organism on Earth, for that matter. In a new study, a team of researchers from Northwestern University and the Uniformed Services University (USU) characterized a synthetic organism inspired by Deinococcus radiodurans that could allow humans to withstand the elevated radiation levels in deep space, on the Moon, and Mars.

The research was led by Hao Yang, a Research Assistant Professor at Northwestern University’s Department of Chemistry. He was joined by Ajay Sharma, also a Research Assistant Professor of Chemistry at Northwestern; Michael J. Daly, a Professor of Pathology at the Uniformed Services University (USU); and Brian M. Hoffman, the Charles E. and Emma H. Morrison Professor of Chemistry and molecular biosciences at Northwestern. The paper detailing their findings appeared on November 8th in the Proceedings of the National Academy of Sciences (PNAS).

Image of the Martian atmosphere and surface obtained by the Viking 1 orbiter in June 1976. (Credit: NASA/Viking 1)

Hoffman is the Charles E. and Emma H. Morrison Professor of Chemistry and professor of molecular biosciences and a member of the Chemistry of Life Processes Institute and the Robert H. Lurie Comprehensive Cancer Center at Northwestern University. Daly, an expert on Deinococcus radiodurans, is also a member of the National Academies’ Committee on Planetary Protection. In a previous study, Hoffman and Daly investigated D. radiodurans‘ ability to withstand radiation on Mars. Earlier research has shown that the bacterium can survive 25,000 grays, which is five times the lethal dose for a human.

However, Hoffman and Daly found that D. radiodurans could withstand 140,000 grays when dried or frozen – 28,000 times the lethal dose for a human! This means that frozen microbes beneath the surface of Mars could survive the cosmic and solar radiation the planet is exposed to on a daily basis. The key to its resistance, they determined, is simple metabolites that combine with manganese to form a powerful antioxidant. They also found that the radiation dose a microorganism can survive is directly related to the amount of manganese antioxidants it contains.

In this latest study, the research team describes a synthetic designer antioxidant (MDP) inspired by D. radiodurans that is much more effective at resisting radiation. Building on their previous efforts, Hoffman and Daly’s team investigated a designer decapeptide (DP1) that, when combined with phosphate and manganese, forms the free-radical-scavenging agent MDP, which is even better at protecting against radiation damage than D. radiodurans. As Hoffman explained in a Northwestern Now news release:

“It is this ternary complex that is MDP’s superb shield against the effects of radiation. We’ve long known that manganese ions and phosphate together make a strong antioxidant, but discovering and understanding the ‘magic’ potency provided by the addition of the third component is a breakthrough. This study has provided the key to understanding why this combination is such a powerful — and promising — radioprotectant.”

An artist’s concept of Mars explorers and their habitat on the Red Planet. Courtesy NASA

“This new understanding of MDP could lead to the development of even more potent manganese-based antioxidants for applications in health care, industry, defense, and space exploration,” said Daly. Potential applications include synthetic antioxidants that could help protect astronauts from radiation during long-duration missions to deep space. In another study, Daly and his collaborators found MDP is effective in preparing irradiated polyvalent vaccines. This could also have applications for space medicine, ensuring that vaccines typically rendered inactive by radiation remain effective.

Further Reading: Northwestern Now, PNAS

The post This Superbacteria can Withstand Enough Radiation to Kill a Person appeared first on Universe Today.

In the last couple of decades, it’s become increasingly clear that massive galaxies like our own Milky Way host supermassive black holes (SMBHs) in their centres. How they became so massive and how they affect their surroundings are active questions in astronomy. Astronomers working with the James Webb Space Telescope have discovered an SMBH in the early Universe that is accreting mass at a very low rate, even though the black hole is extremely massive compared to its host galaxy.

What’s going on with this SMBH, and what does it tell astronomers about the growth of these gargantuan black holes?

The black hole, named GN-1001830, was discovered as part of JADES (JWST Advanced Deep Extragalactic Survey). It is one of the most massive SMBHs discovered by the JWST in the early Universe. While most present-day SMBHs account for about 0.1 % of the mass of their host galaxies, this one accounts for about 40% of its host galaxy’s mass.

The puzzling thing is that GN-1001830 is consuming the gas it needs to grow at a very low rate and is basically dormant. Is it taking a break? Did it experience accelerated bursts of growth in the past?

The findings are in new research published in Nature titled “A dormant overmassive black hole in the early Universe.” The lead author is Ignas Juodžbalis. Juodžbalis is a grad student at the Kavli Institute for Cosmology at the University of Cambridge.

“The early universe managed to produce some absolute monsters, even in relatively tiny galaxies.”

Ignas Juodžbalis, Kavli Institute for Cosmology, University of Cambridge

The JWST has found many SMBHs already in place, only a few hundred million years after the Big Bang. Some of them are overmassive yet dormant, like GN-1001830. Researchers have developed multiple different models to explain them.

This image shows the JWST Advanced Deep Extragalactic Survey (JADES) region of study. It’s in the same region as the Hubble’s Ultra Deep Field. Image Credit:

One model is the ‘heavy seed‘ model, where primordial gas clouds directly collapsed into black holes that grew to become SMBHs. Another model proposes light seeds that experience powerful bursts of accretion. Both models hold promise, but there’s no certainty. “Yet, current datasets are unable to differentiate between these various scenarios,” Juodžbalis and his co-authors write in their research article.

These overmassive black holes that appear to be dormant are testing astrophysicists’ understanding of how SMBHs form and grow. It’s likely that they go through bursts of growth, and in between those bursts, they lie dormant. One of the problems is that it’s very difficult to spot an SMBH that isn’t actively accreting gas. They’re visible when accreting because the accretion disk heats up and emits light.

This one was only spotted because it’s so massive.

“Even though this black hole is dormant, its enormous size made it possible for us to detect,” said lead author Juodžbalis. “Its dormant state allowed us to learn about the mass of the host galaxy as well. The early universe managed to produce some absolute monsters, even in relatively tiny galaxies.”

The Eddington Limit (also known as Eddington Luminosity) is an important factor in the growth of SMBHs. It is a theoretical upper limit on the mass and luminosity of stellar objects, explaining the luminosity we observe in accreting black holes. The Eddington limit is reached when the outward pressure of radiation exceeds the object’s gravitational power, and it can’t accrete more matter. Objects can also exceed this limit, and when that happens, it’s called Super Eddington accretion. Some researchers suggest that Super Eddington accretion was more common in the early Universe and that it explains not only this overmassive black hole but all of the other massive black holes the JWST has discovered in the Universe’s early times.

“It’s possible that black holes are ‘born big’, which could explain why Webb has spotted huge black holes in the early universe,” said co-author Professor Roberto Maiolino from the Kavli Institute and Cambridge’s Cavendish Laboratory. “But another possibility is they go through periods of hyperactivity, followed by long periods of dormancy.”

“It’s likely that the vast majority of black holes out there are in this dormant state.”

Professor Roberto Maiolino, Kavli Institute and Cambridge’s Cavendish Laboratory

The research is based on the detection of broad H-alpha emissions from the SMBH. Those emissions showed that the overmassive black hole has an estimated mass of approximately 4 × 10? (40 million) solar masses. That’s extremely massive for an object only about 800 million years after the Big Bang. For comparison, Sagittarius A*, the SMBH in the Milky Way, has an estimated mass of about 4.3 million solar masses.

The SMBH in question is one of the most overmassive objects the JWST has found. Its mass is almost 50% of the stellar mass of its host galaxy. That’s about 1,000 times more massive than the relation in local galaxies.

The researchers conducted computer simulations to probe the issue. Their research suggests that the SMBH’s periods of hyperactivity likely exceed the Eddington Limit. The SMBH’s long periods of dormancy and inactivity can last for 100 million years, where the accretion rate is only 0.02 times the Eddington Limit, and are punctuated by episodes of Super Eddington accretion that last for about five or ten million years.

“It sounds counterintuitive to explain a dormant black hole with periods of hyperactivity, but these short bursts allow it to grow quickly while spending most of its time napping,” said Maiolino.

Since these SMBHs spend far more time dormant than they do active, they’re more likely to be spotted during dormancy. However, they’re far more difficult to spot when they’re not actively accreting and emitting radiation from their accretion rings. That’s part of what makes this detection so valuable.

These results are agnostic when it comes to heavy or light seeds. Instead, they’re all about Super Eddington episodes. “It is tempting to speculate that our result favours light seed models. However, the same result would also hold if the models had started with heavy seeds. The key feature that allows the properties of GN-1001830 to be matched is the fact that accretion goes through super-Eddington phases, regardless of the seeding mechanism,” the authors explain.

This set of illustrations explains how a large black hole can form from the direct collapse of a massive cloud of gas a few hundred million years after the Big Bang. Panel #1 shows a massive gas cloud and a galaxy moving towards each other. If the formation of stars in the gas cloud is stalled by radiation from the incoming galaxy – preventing it from forming a new galaxy — the gas can instead be driven to collapse and form a disk and black hole. Panels #2 and #3 show the beginning of this gas collapse in the center of the cloud. A small black hole forms in the center of the disk (panel #4), and the black hole and disk then continue to grow (panel #5). This massive black hole “seed” and its disk then merge with the galaxy shown in panel #1. For a period of time, the black hole is unusually massive compared to the mass of the stars in the galaxy, making it an Overmassive Black Hole (panel #6). Stars and gas from the galaxy are pulled in by the black hole, causing the black hole and disk to grow even larger. Image Credit: NASA/STScI/Lea Hustak

“This was the first result I had as part of my PhD, and it took me a little while to appreciate just how remarkable it was,” said Juodžbalis. “It wasn’t until I started speaking with my colleagues on the theoretical side of astronomy that I was able to see the true significance of this black hole.”

“It’s likely that the vast majority of black holes out there are in this dormant state—I’m surprised we found this one—but I’m excited to think that there are so many more we could find,” said Maiolino.

The post An Early Supermassive Black Hole Took a Little Break Between Feasts appeared first on Universe Today.

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