NASA’s Chandra Identifies an Underachieving Black Hole

This image shows a quasar, a rapidly growing supermassive black hole, which is not achieving what astronomers would expect from it, as reported in our latest press release. Data from NASA’s Chandra X-ray Observatory (blue) and radio data from the NSF’s Karl G. Jansky’s Very Large Array (red) reveal some of the evidence for this quasar’s disappointing impact on its host galaxy.

Known as H1821+643, this quasar is about 3.4 billion light-years from Earth. Quasars are a rare and extreme class of supermassive black holes that are furiously pulling material inwards, producing intense radiation and sometimes powerful jets. H1821+643 is the closest quasar to Earth in a cluster of galaxies.

Quasars are different than other supermassive black holes in the centers of galaxy clusters in that they are pulling in more material at a higher rate. Astronomers have found that non-quasar black holes growing at moderate rates influence their surroundings by preventing the intergalactic hot gas from cooling down too much. This regulates the growth of stars around the black hole.

The influence of quasars, however, is not as well known. This new study of H1821+643 that quasars — despite being so active — may be less important in driving the fate of their host galaxy and cluster than some scientists might expect.

To reach this conclusion the team used Chandra to study the hot gas that H1821+643 and its host galaxy are shrouded in. The bright X-rays from the quasar, however, made it difficult to study the weaker X-rays from the hot gas. The researchers carefully removed the X-ray glare to reveal what the black hole’s influence is, which is reflected in the new composite image showing X-rays from hot gas in the cluster surrounding the quasar. This allowed them to see that the quasar is actually having little effect on its surroundings.

Using Chandra, the team found that the density of gas near the black hole in the center of the galaxy is much higher, and the gas temperatures much lower, than in regions farther away. Scientists expect the hot gas to behave like this when there is little or no energy input (which would typically come from outbursts from a black hole) to prevent the hot gas from cooling down and flowing towards the center of the cluster.

A paper describing these results has been accepted into the Monthly Notices of the Royal Astronomical Society and is available online. The authors are Helen Russell (University of Nottingham, UK), Paul Nulsen (Center for Astrophysics | Harvard & Smithsonian), Andy Fabian (University of Cambridge, UK), Thomas Braben (University of Nottingham), Niel Brandt (Penn State University), Lucy Clews (University of Nottingham), Michael McDonald (Massachusetts Institute of Technology), Christopher Reynolds (University of Maryland), Jeremy Saunders (Max Planck Institute for Extraterrestrial Research), and Sylvain Veilleux (University of Maryland).

NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.

Read more from NASA’s Chandra X-ray Observatory.

For more Chandra images, multimedia and related materials, visit:

https://www.nasa.gov/mission/chandra-x-ray-observatory/

Visual Description:

This composite image shows a quasar, a rare and extreme class of supermassive black hole, that’s located about 3.4 billion light-years from Earth.

At the center of the image is a bright, white, circular light, similar to the beam of a flashlight if it was pointed directly toward you. A fuzzy, bar-shaped structure of red-colored radio light, slightly larger than the width of the white light, surrounds the circular structure. The red bar also extends above and below the white light, stretching in a somewhat straight line from about the one o’clock position to the seven o’clock position on a clock face.

On either side of the red bar, X-ray light is present as blue, wispy clouds of hot gas that are brighter closer to the red and white features. The brighter clouds represent more dense gas.

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998

Jonathan Deal
Marshall Space Flight Center
Huntsville, Ala.
256-544-0034

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Lee Mohon

Contract Specialist Dr. Danielle May

“Not only was I going to school, raising a family, and working a full-time job, but I was also the state director for my sorority [and was responsible for] over 1,200 members at one time. And I think it comes down to perseverance. At the end of the day, you’re going to do what needs to be done if you truly want to get it done. You’re going to make the sacrifices that you need to make in order to be successful.

“I’m a night person. So my big homework hours were between 11 p.m. and 3 a.m. I made the time because it was important. And we all do that — we make the time for what’s important to us. I hear people say, ‘There’s no way I could have done that.’ Well, it’s easy when you truly want something with your whole heart.

“…When I actually defended my dissertation and my family was able to attend, that’s when it hit them. They were like, ‘You did all this while we were asleep? You did all this while we were on family vacation?’ I could feel the pride from them because for them, it seemed like it was seamless. But for me, it was heavy. It was heavy, but necessary.

“I believe in giving people their roses while they’re still here to collect them. A few years before I started my doctorate program, my mother had a medical issue and we thought we were going to lose her. And that was the point that I said, ‘I need to go to school and I need to do this for her, because I want her to see me walk across that stage.’

“[Getting my doctorate] made me sit up a little straighter. It’s made me smile a little bit more. It’s made me feel like I can do anything. Not many people can say that.

“…It is something that at the end of the day, no one could ever take away from me. Ever. No matter how much money I have in the bank, no matter where I live or if I have a roof over my head, no one can ever take that away.”

– Dr. Danielle May, Contract Specialist, NASA’s Langley Research Center

Image Credit: NASA/Mark Knopp
Interviewer: NASA/Thalia Patrinos

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Tahira S. Allen

Five Tips from NASA for Photographing a Total Solar Eclipse

A total solar eclipse creates stunning celestial views for people within the path of the Moon’s shadow. This astronomical event is a unique opportunity for scientists to study the Sun and its influence on Earth, but it’s also a perfect opportunity to capture unforgettable images. Whether you’re an amateur photographer or a selfie master, try out these tips for photographing the eclipse.  

#1 – Safety First

Looking directly at the Sun is dangerous to your eyes and your camera. To take images when the Sun is partially eclipsed, you’ll need to use a special solar filter to protect your camera, just as you’ll need a pair of solar viewing glasses (also called eclipse glasses) to protect your eyes. However, at totality, when the Moon completely blocks the Sun, make sure to remove the filter so you can see the Sun’s outer atmosphere – the corona.

#2 – Any Camera Is a Good Camera

Taking a stunning photo has more to do with the photographer than the camera. Whether you have a high-end DLSR or a camera phone, you can take great photos during the eclipse; after all, the best piece of equipment you can have is a good eye and a vision for the image you want to create. If you don’t have a telephoto zoom lens, focus on taking landscape shots and capture the changing environment.

Having a few other pieces of equipment can also come in handy during the eclipse. Using a tripod can help you stabilize the camera and avoid taking blurry images when there is low lighting. Additionally, using a delayed shutter release timer will allow you to snap shots without jiggling the camera.

#3 – Look Up, Down, All Around

While the Sun is the most commanding element of a solar eclipse, remember to look around you. As the Moon slips in front of the Sun, the landscape will be bathed in eerie lighting and shadows. As light filters through the overlapping leaves of trees, it creates natural pinholes that project miniature eclipse replicas on the ground. Anywhere you can point your camera can yield exceptional imagery, so be sure to compose some wide-angle photos that can capture your eclipse experience.

NASA photographer Bill Ingalls recommends focusing on the human experience of watching the eclipse. “The real pictures are going to be of the people around you pointing, gawking, and watching it,” Ingalls noted. “Those are going to be some great moments to capture to show the emotion of the whole thing.”

#4 – Practice

Be sure you know the capabilities of your camera before eclipse day. Most cameras, and even some camera phones, have adjustable exposures, which can help you darken or lighten your image during the tricky eclipse lighting. Make sure you know how to manually focus the camera for crisp shots.

For DSLR cameras, the best way to determine the correct exposure is to test settings on the uneclipsed Sun beforehand. Using a fixed aperture of f/8 to f/16, try shutter speeds between 1/1000 to 1/4 second to find the optimal setting, which you can then use to take images during the partial stages of the eclipse. During totality, the corona has a wide range of brightness, so it’s best to use a fixed aperture and a range of exposures from approximately 1/1000 to 1 second.

#5 – Share!

Share your eclipse experience with friends and family afterwards. Tag @NASA to connect your photos on social media to those taken around the country and share them with NASA.

While you’re snapping those eclipse photos, don’t forget to stop and look at the eclipse with your own eyes. Just remember to wear your solar viewing glasses (also called eclipse glasses) for all stages of the eclipse before and after totality!

Related Links

• Learn more about the 2024 total solar eclipse
• Eclipse Photographers Will Help Study Sun During Its Disappearing Act

By Mara Johnson-Groh
NASA’s Goddard Space Flight Center, Greenbelt, Md.

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NASA’s Hubble Finds that Aging Brown Dwarfs Grow Lonely

It takes two to tango, but in the case of brown dwarfs that were once paired as binary systems, that relationship doesn’t last for very long, according to a recent survey from NASA’s Hubble Space Telescope.

Brown dwarfs are interstellar objects larger than Jupiter but smaller than the lowest-mass stars. They are born like stars – out of a cloud of gas and dust that collapses – but do not have enough mass to sustain the fusion of hydrogen like a normal star.

Astronomers using Hubble confirm that companions are extremely rare around the lowest-mass and coldest brown dwarfs. Hubble can detect binaries as close to each other as a 300-million-mile separation – the approximate separation between our Sun and the asteroid belt. But they didn’t find any binary pairs in a sample of  brown dwarfs in the solar neighborhood. This implies that a binary pair of dwarfs is so weakly linked by gravity that they drift apart over a few hundred million years due to the pull of bypassing stars.

“Our survey confirms that widely separated companions are extremely rare among the lowest-mass and coldest isolated brown dwarfs, even though binary brown dwarfs are observed at younger ages. This suggests that such systems do not survive over time,” said lead author Clémence Fontanive of the Trottier Institute for Research on Exoplanets, Université de Montréal, Canada.

In a similar survey Fontanive conducted a couple of years ago, Hubble looked at extremely young brown dwarfs and some had binary companions, confirming that star-forming mechanisms do produce binary pairs among low-mass brown dwarfs. The lack of binary companions for older brown dwarfs suggests that some may have started out as binaries, but parted ways over time.

The new Hubble findings, published in The Monthly Notices of the Royal Astronomical Society, further support the theory that brown dwarfs are born the same way as stars, through the gravitational collapse of a cloud of molecular hydrogen. The difference being that they do not have enough mass to sustain nuclear fusion of hydrogen for generating energy, whereas stars do. More than half of the stars in our galaxy have a companion star that resulted from these formation processes, with more massive stars more commonly found in binary systems. “The motivation for the study was really to see how low in mass the trends seen among multiple stars systems hold up,” said Fontanive.

“Our Hubble survey offers direct evidence that these binaries that we observe when they’re young are unlikely to survive to old ages, they’re likely going to get disrupted. When they’re young, they’re part of a molecular cloud, and then as they age the cloud disperses. As that happens, things start moving around and stars pass by each other. Because brown dwarfs are so light, the gravitational hold tying wide binary pairs is very weak, and bypassing stars can easily tear these binaries apart,” said Fontanive.

The team selected a sample of brown dwarfs previously identified by NASA’s Wide-Field Infrared Survey Explorer. It sampled some of the coldest and lowest-mass old brown dwarfs in the solar neighborhood. These old brown dwarfs are so cool (a few hundred degrees warmer than Jupiter in most cases) that their atmospheres contain water vapor that condensed out.

To find the coolest companions, the team used two different near-infrared filters, one in which cold brown dwarfs are bright, and another covering specific wavelengths where they appear very faint due to water absorption in their atmospheres.  

“This is the best observational evidence to date that brown dwarf pairs drift apart over time,” said Fontanive. “We could not have done this kind of survey and confirmed earlier models without Hubble’s sharp vision and sensitivity.”

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. Goddard also conducts mission operations with Lockheed Martin Space based in Denver, Colorado. The Space Telescope Science Institute in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

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Media Contacts:

Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov

Ray Villard
Space Telescope Science Institute, Baltimore, MD

Science Contact:
Clémence Fontanive
Trottier Institute for Research on Exoplanets at Université de Montréal

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