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NASA’s Chandra Releases Deep Cut From Catalog of Cosmic Recordings

By: Lee Mohon
23 January 2026 at 13:02
5 Min Read

NASA’s Chandra Releases Deep Cut From Catalog of Cosmic Recordings

This image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively.

Like a recording artist who has had a long career, NASA’s Chandra X-ray Observatory has a “back catalog” of cosmic recordings that is impossible to replicate. To access these X-ray tracks, or observations, the ultimate compendium has been developed: the Chandra Source Catalog (CSC).

The CSC contains the X-ray data detected up to the end of 2020 by Chandra, the world’s premier X-ray telescope and one of NASA’s “Great Observatories.” The latest version of the CSC, known as CSC 2.1, contains over 400,000 unique compact and extended sources and over 1.3 million individual detections in X-ray light.

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This image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively.
This image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively.
NASA/CXC/SAO; Image Processing: NASA/CXC/SAO/N. Wolk
This image is the sum of 86 observations added together, representing over three million seconds of Chandra observing time. It spans just about 60 light-years across, which is a veritable pinprick on the entire sky. The underlying image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively. The annotations on the image show where Chandra has detected over 3,300 individual sources in this field of view over a 22-year timeframe.
This image is the sum of 86 observations added together, representing over three million seconds of Chandra observing time. It spans just about 60 light-years across, which is a veritable pinprick on the entire sky. The underlying image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively. The annotations on the image show where Chandra has detected over 3,300 individual sources in this field of view over a 22-year timeframe.
NASA/CXC/SAO; Image Processing: NASA/CXC/SAO/N. Wolk
This image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively.
This image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively.
NASA/CXC/SAO; Image Processing: NASA/CXC/SAO/N. Wolk
This image is the sum of 86 observations added together, representing over three million seconds of Chandra observing time. It spans just about 60 light-years across, which is a veritable pinprick on the entire sky. The underlying image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively. The annotations on the image show where Chandra has detected over 3,300 individual sources in this field of view over a 22-year timeframe.
This image is the sum of 86 observations added together, representing over three million seconds of Chandra observing time. It spans just about 60 light-years across, which is a veritable pinprick on the entire sky. The underlying image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively. The annotations on the image show where Chandra has detected over 3,300 individual sources in this field of view over a 22-year timeframe.
NASA/CXC/SAO; Image Processing: NASA/CXC/SAO/N. Wolk
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Before and After

X-ray Images of Sagittarius A*

1999 – 2021

This image is the sum of 86 observations added together, representing over three million seconds of Chandra observing time. It spans just about 60 light-years across, which is a veritable pinprick on the entire sky. The underlying image contains lower-, medium-, and higher-energy X-rays in red, green, and blue respectively. The annotations on the image show where Chandra has detected over 3,300 individual sources in this field of view over a 22-year timeframe.

Within the CSC, there is a wealth of information gleaned from the Chandra observations — from precise positions on the sky to information about the the X-ray energies detected. This allows scientists using other telescopes — both on the ground and in space including NASA’s James Webb and Hubble Space Telescopes — to combine this unique X-ray data with information from other types of light.

The richness of the Chandra Source Catalog is illustrated in a new image of the Galactic Center, the region around the supermassive black hole at the center of the Milky Way galaxy called Sagittarius A*. In this image that spans just about 60 light-years across, a veritable pinprick on the entire sky, Chandra has detected over 3,300 individual sources that emit X-rays. This image is the sum of 86 observations added together, representing over three million seconds of Chandra observing time.

Another new representation of the vast scope of the Chanda Source Catalog is found in a just-released sonification, the translation of astronomical data into sound. This sonification encompasses the new map that includes 22 years of Chandra observations across the sky, beginning from its launch through its observations in 2021. Because many X-ray sources have been observed multiple times over the life of the Chandra mission, this sonification represents those repeat X-ray sightings over time through different notes.

Chandra Source Catalog Sonification.
NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida

In the view of the sky, projected in a similar way to how the Earth is often depicted in world maps, the core of the Milky Way is in the center and the Galactic plane is horizontal across the middle of the image. A circle appears at the position of each detection and the size of the circle is determined by the number of detections in that location over time. A year counter appears at the top of the frame. Since Chandra continues to be fully operational, the text changes to “… and beyond” after 2021 as the telescope continues to collect observations. During the video, a collage of images produced by Chandra fades in as a background. In the final frames of the video, thumbnail images representing the thousands of Chandra observations taken over the lifetime of the mission appear behind the sky map.

The most recent version of the Chandra Source Catalog can be accessed at https://cxc.cfa.harvard.edu/csc/

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

To learn more about Chandra, visit:

https://science.nasa.gov/chandra

Read more from NASA’s Chandra X-ray Observatory

Learn more about the Chandra X-ray Observatory and its mission here:

https://www.nasa.gov/chandra

https://chandra.si.edu

Visual Description

A very deep Chandra X-ray Observatory image around the Sagittarius A* supermassive black hole, located in the center of the Milky Way galaxy, is shown. The image is dominated by burnt orange, deep gold and blue hues, with a sprinkling of rich green. The area looks both intricate and full, with a dense population of tiny dots, along with larger clumps and diffuse areas and nebulous areas peeking through.

At the center of the image, there is a bright, lumpy area in pale gold showing the intense X-ray radiation emanating from the Sagittarius A* black hole. In the surrounding area, there are more smaller lumps layered throughout, feathering out to a large almost butterfly shape filling much of the screen. The image appears textured, like dozens of blue and orange glow worms are paused in their wriggling.

The image offers an unprecedented view of lobes of hot gas extending for a dozen light years on either side of the black hole. These lobes provide evidence for powerful eruptions occurring several times over the last ten thousand years. The image also contains several mysterious X-ray filaments, some of which may be huge magnetic structures interacting with streams of energetic electrons produced by rapidly spinning neutron stars. Such features are known as pulsar wind nebulas. Chandra has detected over 3,300 individual sources that emit X-rays in this field of view. This image is the sum of 86 observations added together, representing over three million seconds of Chandra observing time.

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov

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Last Updated
Jan 23, 2026
Editor
Lee Mohon
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NASA’s IXPE Measures White Dwarf Star for First Time

By: Lee Mohon
5 January 2026 at 16:58
This artist’s concept depicts a smaller white dwarf star pulling material from a larger star, right, into an accretion disk. Earlier this year, scientists used NASA’s IXPE (Imaging X-ray Polarization Explorer) to study a white dwarf star and its X-ray polarization.
This artist’s concept depicts a smaller white dwarf star pulling material from a larger star, right, into an accretion disk. Earlier this year, scientists used NASA’s IXPE (Imaging X-ray Polarization Explorer) to study a white dwarf star and its X-ray polarization.
MIT/Jose-Luis Olivares

By Michael Allen 

For the first time, scientists have used NASA’s IXPE (Imaging X-ray Polarization Explorer) to study a white dwarf star. Using IXPE’s unique X-ray polarization capability, astronomers examined a star called the intermediate polar EX Hydrae, unlocking the geometry of energetic binary systems. 

In 2024, IXPE spent nearly one week focused on EX Hydrae, a white dwarf star system located in the constellation Hydra, approximately 200 light-years from Earth. A paper about the results published in the Astrophysical Journal. Astrophysics research scientists based at the Massachusetts Institute of Technology in Cambridge led the study, along with co-authors at the University of Iowa, East Tennessee State University, University of Liége, and Embry Riddle Aeronautical University. 

A white dwarf star occurs after a star runs out of hydrogen fuel to fuse in its core but is not massive enough to explode as core-collapse supernovae. What remains is very dense, roughly the same diameter as Earth with as much mass as our Sun.  

EX Hydrae is in a binary system with a main sequence companion star, from which gas is continuously falling onto the white dwarf. How exactly the white dwarf is accumulating, or accreting, this matter and where it arrives on the white dwarf depends on the strength of the white dwarf star’s magnetic field. 

In the case of EX Hydrae, its magnetic field is not strong enough to focus matter completely at the star’s poles. But, it is still rapidly adding mass to the accretion disk, earning the classification “intermediate polars. 

In an intermediate polar system, material forms an accretion disk while also being pulled towards its magnetic poles. During this phenomenon, matter reaches tens of millions of degrees Fahrenheit, bouncing off other material bound to the white dwarf star, creating large columns of gas that emit high-energy X-rays – a cosmic situation perfect for IXPE to study.

“NASA IXPE’s one-of-a-kind polarimetry capability allowed us to measure the height of the accreting column from the white dwarf star to be almost 2,000 miles high – without as many assumptions required as past calculations,” said Sean Gunderson, MIT scientist and lead author on the paper. “The X-rays we observed likely scattered off the white dwarf’s surface itself. These features are far smaller than we could hope to image directly and clearly show the power of polarimetry to ‘see’ these sources in detail never before possible.”

Information from IXPE’s polarization data of EX Hydrae will help scientists understand other highly energetic binary systems.

More about IXPE 

 The IXPE mission, which continues to provide unprecedented data enabling groundbreaking discoveries about celestial objects across the universe, is a joint NASA and Italian Space Agency mission with partners and science collaborators in 12 countries. It is led by NASA’s Marshall Space Flight Center in Huntsville, Alabama. BAE Systems, Inc., headquartered in Falls Church, Virginia, manages spacecraft operations together with the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder. Learn more about IXPE’s ongoing mission here: 

https://www.nasa.gov/ixpe

NASA’s Chandra Rings in New Year With Champagne Cluster

By: Lee Mohon
30 December 2025 at 11:45
This release features a composite image of a galaxy cluster first discovered on New Year's Eve day, 2020. The cluster appears here as a large collection of brilliant white lights, each a distinct galaxy. A neon purple cloud stretches across the cluster's crowded core. Many of the hundred-plus galaxies in the cluster are in two clumps of galaxies towards the top and bottom of center. Some are encircled by a faint glowing haze, while a few foreground stars gleam with diffraction spikes. Some of the smaller galaxies are tinted blue, orange, or red, and some appear more oblong than round, suggesting spiral shapes viewed edge-on. The neon purple cloud sits at the heart of the image, surrounding the most densely-packed part of the cluster. This cloud, which spreads vertically across the cluster, is multimillion-degree gas observed by Chandra. The two clumps of observable galaxies, and the spread of superheated gas, reveal that the Champagne Cluster is in fact two clusters in the process of colliding. With the two clusters of sparkling light clinking together, and the auspicious discovery date, astronomers have dubbed the merged cosmic structure "The Champagne Cluster".
X-ray: NASA/CXC/UCDavis/F. Bouhrik et al.; Optical:Legacy Survey/DECaLS/BASS/MzLS; Image Processing: NASA/CXC/SAO/P. Edmonds and L. Frattare

Celebrate the New Year with the “Champagne Cluster,” a galaxy cluster seen in this new image from NASA’s Chandra X-ray Observatory and optical telescopes.

Astronomers discovered this galaxy cluster Dec. 31, 2020. The date, combined with the bubble-like appearance of the galaxies and the superheated gas seen with Chandra observations (represented in purple), inspired the scientists to nickname the galaxy cluster the Champagne Cluster, a much easier-to-remember name than its official designation of RM J130558.9+263048.4.

The new composite image shows that the Champagne Cluster is actually two galaxy clusters in the process of merging to form an even larger cluster. Multimillion-degree gas in galaxy clusters usually takes on an approximately circular or moderately oval shape in images, but in the Champagne Cluster it is more widely spread from top to bottom, revealing the presence of the two colliding clusters. Two clumps of individual galaxies making up the colliding clusters can be seen toward the top and bottom of center. (The image has been rotated clockwise by 90 degrees so that North points to the right.)

The hot gas outweighs the combined mass in all of the hundred-plus individual galaxies in the newly forming cluster. The clusters also contain even larger amounts of unseen dark matter, the mysterious substance that pervades the universe.

In addition to the Chandra data, this new image contains optical data from the Legacy Surveys (red, green, and blue), which consists of three individual and complementary surveys from various telescopes in Arizona and Chile.

The Champagne Cluster is a member of a rare class of merging clusters, which includes the well-known Bullet Cluster, where the hot gas in each cluster has collided and slowed down, and there is a clear separation between the hot gas and the most massive galaxy in each cluster.

By comparing the data with computer simulations, astronomers came up with two possibilities for the history of the Champagne Cluster. One is that the two clusters already collided with each other over two billion years ago. After the collision the two clusters traveled outward and then were pulled back toward each other by gravity, and are now heading into a second collision. The other idea is that a single collision occurred about 400 million years ago, and the two clusters are now traveling away from each other after that collision. Researchers think further studies of the Champagne Cluster can potentially teach them how dark matter reacts to a high-speed collision.

A paper describing these results recently appeared in The Astrophysical Journal and is available online. The authors of the paper are Faik Bouhrik, Rodrigo Stancioli, and David Wittman, all from the University of California, Davis.

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


Read more from NASA’s Chandra X-ray Observatory

Learn more about the Chandra X-ray Observatory and its mission here:

https://www.nasa.gov/chandra

https://chandra.si.edu

Visual Description

This release features a composite image of a galaxy cluster discovered on New Year’s Eve day, 2020.

The cluster appears here as a large collection of brilliant white lights, each a distinct galaxy. A neon purple cloud stretches across the cluster’s crowded core. Many of the hundred-plus galaxies in the cluster are in two clumps of galaxies towards the top and bottom of center. Some are encircled by a faint glowing haze, while a few foreground stars gleam with diffraction spikes. Some of the smaller galaxies are tinted blue, orange, or red, and some appear more oblong than round, suggesting spiral shapes viewed edge-on.

The neon purple cloud sits at the heart of the image, surrounding the most densely-packed part of the cluster. This cloud, which spreads vertically across the cluster, is multimillion-degree gas observed by Chandra. The two clumps of observable galaxies, and the spread of superheated gas, reveal that the Champagne Cluster is in fact two clusters in the process of colliding.

With the two clusters of sparkling light clinking together, and the auspicious discovery date, astronomers have dubbed the merged cosmic structure “The Champagne Cluster”.

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov

NASA IXPE’s Longest Observation Solves Black Hole Jets Mystery

By: Lee Mohon
16 December 2025 at 16:23

4 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

The Perseus Cluster. Left: Imaging X-ray Polarimetry Explorer (IXPE); Right: Chandra X-ray Observatory.
Two composite images show side-by-side observations of the Perseus Cluster from NASA’s IXPE (Imaging X-Ray Polarimetry Explorer) and Chandra X-ray Observatory. Scientists used data from both observatories, along with data from Nuclear Spectroscopic Telescope Array (NuSTAR), and Neil Gehrels Swift Observatory, to confirm measurements of the galaxy cluster.
X-ray: (Chandra) NASA/CXC/SAO, (IXPE) NASA/MSFC; Image Processing: NASA/CXC/SAO/N. Wolk and K. Arcand

Written by Michael Allen

An international team of astronomers using NASA’s IXPE (Imaging X-ray Polarimetry Explorer) has identified the origin of X-rays in a supermassive black hole’s jet, answering a question that has been unresolved since the earliest days of X-ray astronomy. Their findings are described in a paper published in The Astrophysical Journal Letters, by the American Astronomical Society, Nov. 11.

The IXPE mission observed the Perseus Cluster, the brightest galaxy cluster observable in X-rays, for more than 600 hours over a 60-day period between January and March. Not only is this IXPE’s longest observation of a single target to date, it also marks IXPE’s first time observing a galaxy cluster.

Specifically, the team of scientists studied the polarization properties of 3C 84, the massive active galaxy located at the very center of the Perseus Cluster. This active galaxy is a well-known X-ray source and a common target for X-ray astronomers because of its proximity and brightness.

Because the Perseus Cluster is so massive, it hosts an enormous reservoir of X-ray emitting gas as hot as the core of the Sun. The use of multiple X-ray telescopes, particularly the high-resolution imaging power of NASA’s Chandra X-ray Observatory was essential to disentangle the signals in the IXPE data. Scientists combined these X-ray measurements with data from the agency’s Nuclear Spectroscopic Telescope Array (NuSTAR) mission and Neil Gehrels Swift Observatory.

Fast facts

  • Polarization measurements from IXPE carry information about the orientation and alignment of emitted X-ray light waves. The more X-ray waves traveling in sync, the higher the degree of polarization.
  • X-rays from an active galaxy like 3C 84 are thought to originate from a process known as inverse Compton scattering, where light bounces off particles and gains energy. The polarization measurements from IXPE allow us to identify the presence of either inverse Compton scattering or other scenarios.
  • “Seed photons” is the term for the lower-energy radiation undergoing the energizing process of inverse Compton scattering.
  • You may remember the Perseus Cluster from this sonification replicating what a Black Hole sounds like from May 2022.

“While measuring the polarization of 3C 84 was one of the key science goals, we are still searching for additional polarization signals in this galaxy cluster that could be signatures of more exotic physics,” said Steven Ehlert, project scientist for IXPE and astronomer at NASA’s Marshall Space Flight Center in Huntsville.

Chandra & IXPE composite image of the Perseus Cluster.
Chandra & IXPE composite image of the Perseus Cluster.
X-ray: (Chandra) NASA/CXC/SAO, (IXPE) NASA/MSFC; Image Processing: NASA/CXC/SAO/N. Wolk and K. Arcand

“We’ve already determined that for sources like 3C 84, the X-rays originated from inverse Compton scattering,” said Ioannis Liodakis, a researcher at the Institute of Astrophysics – FORTH in Heraklion, Greece, and lead author on the paper. “With IXPE observations of 3C 84 we had a unique chance to determine the properties of the seed photons.”

The first possible origin scenario for the seed photons is known as synchrotron self-Compton, where lower-energy radiation originates from the same jet that produces the highly energetic particles.

In the alternative scenario known as external Compton, seed photons originate from background radiation sources unrelated to the jet.

“The synchrotron self-Compton and external Compton scenarios have very different predictions for their X-ray polarization,” said Frederic Marin, an astrophysicist at the Strasbourg Astronomical Observatory in France and co-author of the study. “Any detection of X-ray polarization from 3C 84 almost decisively rules out the possibility of external Compton as the emission mechanism.”

Throughout the 60-day observation campaign, optical and radio telescopes around the world turned their attention to 3C 84 to further test between the two scenarios.

NASA’s IXPE measured a net polarization of 4% in the X-rays spectrum, with comparable values measured in the optical and radio data. These results strongly favor the synchrotron self-Compton model for the seed photons, where they come from the same jet as the higher-energy particles.

“Separating these two components was essential to this measurement and could not be done by any single X-ray telescope, but by combining the IXPE polarization data with Chandra, NuSTAR, and Swift, we were able to confirm this polarization measurement was associated specifically with 3C 84,” said Sudip Chakraborty, a researcher at the Science and Technology Institute of the Universities Space Research Association in Huntsville, Alabama, and co-author on the paper.

Scientists will continue to analyze IXPE’s data from different locations in the Perseus Cluster for different signals.

More about IXPE

NASA’s IXPE, which continues to provide unprecedented data enabling groundbreaking discoveries about celestial objects across the universe, is a joint NASA and Italian Space Agency mission with partners and science collaborators in 12 countries. The IXPE mission is led by NASA’s Marshall Space Flight Center in Huntsville, Alabama. BAE Systems, Inc., headquartered in Falls Church, Virginia, manages spacecraft operations together with the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder.

Learn more about IXPE’s ongoing mission here:

https://www.nasa.gov/ixpe

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