ESO captures the ghost of a giant star

PR Image eso2214a
The Vela supernova remnant imaged by the VLT Survey Telescope

PR Image eso2214b
Highlights of the Vela supernova remnant

PR Image eso2214c
VST image processing workflow

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Videos

PR Video eso2214a

Flying through the remnants of a dead star

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A spooky spider web, magical dragons or wispy trails of ghosts? What do you see in this image of the Vela supernova remnant? This beautiful tapestry of colours shows the ghostly remains of a gigantic star, and was captured here in incredible detail with the VLT Survey Telescope, hosted at the European Southern Observatory’s (ESO’s) Paranal site in Chile.

The wispy structure of pink and orange clouds is all that remains of a massive star that ended its life in a powerful explosion around 11 000 years ago. When the most massive stars reach the end of their life, they often go out with a bang, in an outburst called a supernova. These explosions cause shock waves that move through the surrounding gas, compressing it and creating intricate thread-like structures. The energy released heats the gaseous tendrils, making them shine brightly, as seen in this image.

In this 554-million-pixel image, we get an extremely detailed view of the Vela supernova remnant, named after the southern constellation Vela (The Sails). You could fit nine full Moons in this entire image, and the whole cloud is even larger. At only 800 light-years away from Earth, this dramatic supernova remnant is one of the closest known to us.

As it exploded, the outermost layers of the progenitor star were ejected into the surrounding gas, producing the spectacular filaments that we observe here. What remains of the star is an ultra-dense ball in which the protons and electrons are forced together into neutrons — a neutron star. The neutron star in the Vela remnant, placed slightly outside of this image to the upper left, happens to be a pulsar that spins on its own axis at an incredible speed of more than 10 times per second.

This image is a mosaic of observations taken with the wide-field camera OmegaCAM at the VLT Survey Telescope (VST), hosted at ESO’s Paranal Observatory in Chile. The 268-million-pixel camera can take images through several filters that let through light of different colours. In this particular image of the Vela remnant, four different filters were used, represented here by a combination of magenta, blue, green and red.

The VST is owned by The National Institute for Astrophysics in Italy, INAF, and with its 2.6-metre mirror it is one of the largest telescopes dedicated to surveying the night sky in visible light. This image is an example from such a survey: the VST Photometric Hα Survey of the Southern Galactic Plane and Bulge (VPHAS+). For over seven years, this survey has mapped a considerable portion of our home galaxy, allowing astronomers to better understand how stars form, evolve and eventually die.

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More Information

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration in astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as survey telescopes such as VISTA. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates APEX and ALMA on Chajnantor, two facilities that observe the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society.

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Links

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Contact:

Juan Carlos Muñoz Mateos
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Garching bei München, Germany
Tel: +49 89 3200 6176
Email: press@eso.org

Source: ESO/News

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Rare Earth Element Synthesis Confirmed in Neutron Star Mergers

Artist’s conception of a neutron star merger and the resulting kilonova.
Credit: Tohoku University) Original size (5.3MB)

A group of researchers has, for the first time, identified rare earth elements produced by neutron star mergers.

When two neutron stars spiral inwards and merge, the resulting explosion produces a large amount of the heavy elements that make up our Universe. The first confirmed example of this process was an event in 2017 named GW 170817. Yet, even now 5 years later, identifying the specific elements created in neutron star mergers has eluded scientists, except for strontium identified in the optical spectra.

A research group led by Nanae Domoto, a graduate student at the Graduate School of Science at Tohoku University and a research fellow at the Japan Society for the Promotion of Science (JSPS), has systematically studied the spectra from this kilonova—bright emissions caused by the radioactive decay of freshly synthesized nuclei that were ejected during the GW 170817 merger. Based on comparisons of detailed kilonovae spectra simulations produced by the supercomputer “ATERUI II” at the National Astronomical Observatory of Japan, the team found that the rare earth elements lanthanum and cerium can reproduce the near-infrared spectral features seen in 2017.

Until now, the existence of rare earth elements has only been hypothesized based on the overall evolution of the brightness of the kilonova, but not confirmed from the spectral features.

“This is the first direct identification of rare elements in the spectra of neutron star mergers, and it advances our understanding of the origin of elements in the Universe,” Dotomo said.

“This study used a simple model of ejected material. Looking ahead, we want to factor in multi-dimensional structures to grasp a bigger picture of what happens when stars collide,” Dotomo added.

These results appeared as Domoto et al. “Lanthanide Features in Near-infrared Spectra of Kilonovae” in The Astrophysical Journal on October 26, 2022.

Source: National Astronomical Observatory of Japan (NAOJ)/New/Science

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Related Links

• Rare Earth Element Synthesis Confirmed in Neutron Star Mergers (Center for Computational Astrophysics)
• Rare Earth Elements Synthesis Confirmed in Neutron Star Mergers (Tohoku University)

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Haunting Portrait: NASA’s Webb Reveals Dust, Structure in Pillars of Creation

Pillars of Creation (MIRI Image)
Credits: Science: NASA, ESA, CSA, STScI
Image Processing: Joseph DePasquale (STScI), Alyssa Pagan (STScI)
Release Images | Release Videos

This is not an ethereal landscape of time-forgotten tombs. Nor are these soot-tinged fingers reaching out. These pillars, flush with gas and dust, enshroud stars that are slowly forming over many millennia. NASA’s James Webb Space Telescope has snapped this eerie, extremely dusty view of the Pillars of Creation in mid-infrared light – showing us a new view of a familiar landscape.

Why does mid-infrared light set such a somber, chilling mood in Webb’s Mid-Infrared Instrument (MIRI) image? Interstellar dust cloaks the scene. And while mid-infrared light specializes in detailing where dust is, the stars aren’t bright enough at these wavelengths to appear. Instead, these looming, leaden-hued pillars of gas and dust gleam at their edges, hinting at the activity within.

Thousands and thousands of stars have formed in this region. This is made plain when examining Webb’s recent Near-Infrared Camera (NIRCam) image. In MIRI’s view, the majority of the stars appear missing. Why? Many newly formed stars are no longer surrounded by enough dust to be detected in mid-infrared light. Instead, MIRI observes young stars that have not yet cast off their dusty “cloaks.” These are the crimson orbs toward the fringes of the pillars. In contrast, the blue stars that dot the scene are aging, which means they have shed most of their layers of gas and dust.

Mid-infrared light excels at observing gas and dust in extreme detail. This is also unmistakable throughout the background. The densest areas of dust are the darkest shades of gray. The red region toward the top, which forms an uncanny V, like an owl with outstretched wings, is where the dust is diffuse and cooler. Notice that no background galaxies make an appearance – the interstellar medium in the densest part of the Milky Way’s disk is too swollen with gas and dust to allow their distant light to penetrate. How vast is this landscape? Trace the topmost pillar, landing on the bright red star jutting out of its lower edge like a broomstick. This star and its dusty shroud are larger than the size of our entire solar system.

This scene was first captured by NASA’s Hubble Space Telescope in 1995 and revisited in 2014, but many other observatories, like NASA’s Spitzer Space Telescope, have also gazed deeply at the Pillars of Creation. With every observation, astronomers gain new information, and through their ongoing research build a deeper understanding of this star-forming region. Each wavelength of light and advanced instrument delivers far more precise counts of the gas, dust, and stars, which inform researchers’ models of how stars form. As a result of the new MIRI image, astronomers now have higher resolution data in mid-infrared light than ever before, and will analyze its far more precise dust measurements to create a more complete three-dimensional landscape of this distant region.

The Pillars of Creation is set within the vast Eagle Nebula, which lies 6,500 light-years away.

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

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Credits:

Media Contact:

Claire Blome
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Source: NASA's James Webb Space Telescope/News

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Researchers Find Hot, Dense Water Vapor in a Protoplanetary Disk

Artist's impression of a protoplanetary disk around a young star.
Credit: A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO); CC BY 4.0

Recent observations of the protoplanetary disks hosted by a pair of young stars suggest the presence of hot, turbulent water vapor. Though many possibilities exist, researchers propose that a compact disk around a young planet could be the source of this rare spectral signature.

llustration of the protoplanetary disks around stars in a binary system.
Credit: R. Hurt (NASA/JPL-Caltech/IPAC)

Planet Formation Locations

Protoplanetary disks are the sites of planet formation, and studies of these disks hold the key to understanding the origins of the planets in our solar system and beyond. However, protoplanetary disks are complex, and teasing out the promised planetary origins relies on understanding the interconnected facets of disk chemistry, structure, and kinematics.

To make matters more complicated, throw another star into the mix: by studying the disks around young binary stars, which are expected to form at the same time from the same material, researchers can probe other aspects of disk development. For example, it’s not yet known whether disk evolution is deterministic (meaning that two disks with the same initial properties will evolve in the same way) or random (meaning that the evolution of identical disks will diverge). In a recent research article, astronomers set out to study dual disk development in a binary system — and found something unusual along the way.

Spectrum of VV CrA A (black) overlaid with models of water vapor emission at different temperatures (green, orange, and blue). Credit: Adapted fromSalyk et al. 2022

Infrared Investigation

Colette Salyk (Vassar College) and collaborators analyzed high-resolution infrared spectra of the two disks in VV Corona Australis (VV CrA), a two-million-year-old binary system containing stars roughly half the Sun’s mass. The disk around one of the stars, VV CrA A, showed an unusually large number of emission lines due to the presence of water vapor — and only one other protoplanetary disk is known to show water emission lines at such long wavelengths.

The second disk in the binary system, VV CrA B, has some of the same spectral features, but emission from water vapor was detected only weakly. This doesn’t necessarily mean that the disk lacks water; instead, water vapor might be present at a lower temperature or density.

Diagrams of the emitting geometry for VV CrA A’s disk and the modeled emission for each scenario.

Credit: Salyk et al. 2022

Disks Find Themselves in Hot Water

Salyk and collaborators modeled VV CrA A’s spectrum and found that the emission likely arises from water vapor that is hot (1500K), dense, turbulent, and spans an area of just 0.003 au2. Intriguingly, further modeling showed that the emission could arise from a water-rich ring circling the central star or a compact ring surrounding a planet in the process of formation — a circumplanetary disk. Detections of circumplanetary disks are rare and often tentative, so being able to identify them via their water emission would be exciting. However, the only stellar systems in which this water feature has been identified are young, which could mean that the presence of hot water vapor is instead tied to a process at work in young disks, like accretion or disk winds.

As is often the case in the study of protoplanetary disks, delving into one question prompts many others. The authors suggest several avenues for future work, including observing VV CrA at near-infrared or submillimeter wavelengths and expanding their modeling of emission from circumplanetary disks. Hopefully, further analysis will illuminate the cause of this unusual water feature!

Citation

“An Unusual Reservoir of Water Emission in the VV CrA A Protoplanetary Disk,” Colette Salyk et al 2022 AJ 164 136. doi:10.3847/1538-3881/ac8878

Source: American Astronomical Society - AAS Nova

LOFAR detects gigantic radio sources in the universe

Artistic representation of the large-scale structure of the Universe above the core of the LOFAR telescope. The inset shows a zoom into a galaxy cluster where a megahalo is observed (orange emission, from LOFAR observations).

An international research team, led by the Observatory of Universität Hamburg has, using LOFAR, discovered four radio sources of up to ten million light years in size: megahalos.

Seen from a great distance, the universe is not evenly distributed; it actually resembles a net-like structure, somewhat similar to the way neurons are connected to one another in the brain. At the nodes of this so-called cosmic web hundreds, sometimes even thousands of galaxies are crowded together into galaxy clusters. Sometimes, two galaxy clusters collide with each other and merge into a single cluster. In the process, they release enormous amounts of energy, so large that they are the most powerful events happening in our Universe after the Big Bang. During these collisions, tiny, charged particles are accelerated to near-lightspeed, emitting radio waves that can be detected with radio telescopes.

Using the Low Frequency Array (LOFAR), scientists have now discovered four galaxy clusters where a faint radio emission envelopes the entire clusters even reaching their outskirts. Dr. Virginia Cuciti led the international research team: “Megahalos extend up to ten million light years) in size, which means that they cover a volume that is about 30 times larger than the volume of the radio sources known so far in galaxy clusters. This implies that with megahalos we can now observe the peripheral regions of galaxy clusters which were previously almost inaccessible.”

Computer simulation of the large-scale structure of the Universe. The inset shows a zoom into a galaxy cluster where a megahalo is observed (orange emission, from LOFAR observations).

Cuciti’s team used LOFAR Two-metre Sky Survey (LoTSS) observations of these four galaxy clusters. While analysing the data of one of the clusters, she and her teammates saw some significant hints of radio emission on exceptionally large scales, Cuciti says. “So, we decided to re-inspect all the images of a sample of 310 clusters that we were studying with the aim of looking for similar emission. When we discovered that three other clusters of this sample showed emission on similar scales and with similar characteristics, it became clear that we discovered a new type of cosmic phenomenon that opens the possibility to explore the external region of galaxy clusters through radio observations.”

This discovery could not have been made without LOFAR, Cuciti says. “It is not by chance that megahalos have been discovered with LOFAR. They are very large, and their emission is very faint. Moreover, the synchrotron spectrum of megahalos is steep, which basically means that they are brighter at low radio frequency, therefore a sensitive radio telescope operating at low radio frequency, such as LOFAR, is the ideal instrument to detect them.”

But even then, it was not easy, co-author and astronomer at ASTRON Timothy Shimwell says: “Even in the very sensitive and wide area LOFAR surveys dataset these objects were very hard to find because they are so faint and a very careful analysis of large quantities of data was required to identify them.”

LOFAR2.0

A region of the LOFAR core seen from above. The two antenna types of LOFAR are visible.

With LOFAR currently undergoing an upgrade to LOFAR2.0, making it an even more sensitive instrument, even more valuable information can be found about megahalos. Cuciti: “With more sensitive observations we could be able to detect megahalos in a much larger number of clusters. This is actually one of the most interesting aspects of this work, because it means that, if megahalos are present in a large fraction of clusters, if not all of them, we are opening a new field of research, a new way to systematically explore the periphery of galaxy clusters with radio observations. The LOFAR 2.0 upgrade will increase the sensitivity of LOFAR, especially in the LBA (at 50 MHz), and will therefore allow us to answer to the question: how many clusters host megahalos?"

The Nature-article Galaxy clusters enveloped by vast volumes of relativistic electrons can be found here.

Source: ASTRON-Netherlands Institute for Radio Astronomy

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NASA’s Webb Uncovers Dense Cosmic Knot in the Early Universe

Motions of Gas Around an Extremely Red Quasar (NIRSpec IFU)
Credits: Image: NASA, ESA, CSA, STScI
Science: Dominika Wylezalek (ZAH), Andrey Vayner (JHU), Nadia Zakamska (JHU), Q-3D Team
Image Processing: Leah Hustak (STScI)

Astronomers looking into the early universe have made a surprising discovery using NASA’s James Webb Space Telescope: a cluster of massive galaxies in the process of forming around an extremely red quasar. The result will expand our understanding of how galaxy clusters in the early universe came together and formed the cosmic web we see today.

A quasar, a special type of active galactic nucleus (AGN), is a compact region with a supermassive black hole at the center of a galaxy. Gas falling into a supermassive black hole makes the quasar bright enough to outshine all the galaxy’s stars.

The quasar Webb explored, called SDSS J165202.64+172852.3, existed 11.5 billion years ago. It is unusually red not just because of its intrinsic red color, but also because the galaxy’s light has been redshifted by its vast distance. That made Webb, having unparalleled sensitivity in infrared wavelengths, perfectly suited to examine the galaxy in detail.

This quasar is one of the most powerful known galactic nuclei that’s been seen at such an extreme distance. Astronomers had speculated that the quasar’s extreme emission could cause a “galactic wind,” pushing free gas out of its host galaxy and possibly greatly influencing future star formation there.

To investigate the movement of the gas, dust, and stellar material in the galaxy, the team used the telescope’s Near Infrared Spectrograph (NIRSpec). This powerful instrument uses a technique called spectroscopy to look at the movement of various outflows and winds surrounding the quasar. NIRSpec can simultaneously gather spectra across the telescope’s whole field of view, instead of just from one point at a time, enabling Webb to simultaneously examine the quasar, its galaxy, and the wider surroundings.

Previous studies by NASA’s Hubble Space Telescope and other observatories called attention to the quasar’s powerful outflows, and astronomers had speculated that its host galaxy could be merging with some unseen partner. But the team was not expecting Webb’s NIRSpec data to clearly indicate it was not just one galaxy, but at least three more swirling around it. Thanks to spectra over a broad area, the motions of all this surrounding material could be mapped, resulting in the conclusion that the red quasar was in fact part of a dense knot of galaxy formation.

“There are few galaxy protoclusters known at this early time. It’s hard to find them, and very few have had time to form since the big bang,” said astronomer Dominika Wylezalek of Heidelberg University in Germany, who led the study with Webb. “This may eventually help us understand how galaxies in dense environments evolve. It’s an exciting result.”

Using the observations from NIRSpec, the team was able to confirm three galactic companions to this quasar and show how they are connected. Archival data from Hubble hint that there may be even more. Images from Hubble’s Wide Field Camera 3 had shown extended material surrounding the quasar and its galaxy, prompting its selection for this study into its outflow and the effects on its host galaxy. Now, the team suspects they could have been looking at the core of a whole cluster of galaxies – only now revealed by Webb’s crisp imaging.

"Our first look at the data quickly revealed clear signs of major interactions between the neighboring galaxies,” shared team member Andrey Vayner of Johns Hopkins University in Baltimore, Maryland. “The sensitivity of the NIRSpec instrument was immediately apparent, and it was clear to me that we are in a new era of infrared spectroscopy."

The three confirmed galaxies are orbiting each other at incredibly high speeds, an indication that a great deal of mass is present. When combined with how closely they are packed into the region around this quasar, the team believes this marks one of the densest known areas of galaxy formation in the early universe. “Even a dense knot of dark matter isn’t sufficient to explain it,” Wylezalek says. “We think we could be seeing a region where two massive halos of dark matter are merging together.” Dark matter is an invisible component of the universe that holds galaxies and galaxy clusters together, and is thought to form a “halo” that extends beyond the stars in these structures.

The study conducted by Wylezalek’s team is part of Webb’s investigations into the early universe. With its unprecedented ability to look back in time, the telescope is already being used to investigate how the first galaxies were formed and evolved, and how black holes formed and influenced the structure of the universe. The team is planning follow-up observations into this unexpected galaxy proto-cluster, and hope to use it to understand how dense, chaotic galaxy clusters like this one form, and how it’s affected by the active, supermassive black hole at its heart.

These results will be published in the The Astrophysical Journal Letters. This research was completed as part of Webb’s Early Release Science program #1335.

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

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Credits:

Media Contact:

Bethany Downer
European Space Agency, Paris, France

Ninja Menning
European Space Agency, Paris, France

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Science Contact:

Dominika Wylezalek
Center for Astronomy of Heidelberg University, Heidelberg, Germany

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents:

• Science Paper: The science paper by D. Wylezalek et al., PDF (3.62 MB)

Source: NASA's James Webb Space Telescope/News

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Black hole discovered firing jet at neighbouring galaxy

Image of the black hole within galaxy RAD12 spewing a large unipolar radio bubble on to its merging companion galaxy.
Credit: Dr Ananda Hota, GMRT, CFHT, MeerKAT. Licence type: Attribution (CC BY 4.0)

With the help of citizen scientists, a team of astronomers has discovered a unique black hole spewing a fiery jet at another galaxy. The black hole is hosted by a galaxy around one billion light years away from Earth named RAD12. The work was published today in Monthly Notices of the Royal Astronomical Society (Letters).

Galaxies are typically divided into two major classes based on their morphology: spirals and ellipticals. Spirals have optically-blue looking spiral arms with an abundance of cold gas and dust. In spiral galaxies, new stars form at an average rate of one Sun-like star per year. In contrast elliptical galaxies appear yellowish and lack distinct features such as spiral arms.

Star formation in elliptical galaxies is very scarce; it is still a mystery to astronomers as to why the elliptical galaxies we see today have not been forming new stars for billions of years. Evidence suggests that supermassive or ‘monster’ black holes are responsible. These ‘monster’ black holes spew gigantic jets made of electrons moving at very high speeds at other galaxies, depleting the fuel required for future star formation: cold gas and dust.

The unique nature of RAD12 had been observed in 2013 using optical data from the Sloan Digitised Sky Survey (SDSS) and radio data from the Very Large Array (FIRST survey). However, follow-up observation with the Giant Meterwave Radio Telescope (GMRT) in India was required to confirm its truly exotic nature: The black hole in RAD12 appears to be ejecting the jet only towards a neighbouring galaxy, named RAD12-B. In all cases, jets are ejected in pairs, moving in opposite directions at relativistic speeds. Why only one jet is seen coming from RAD12 remains a puzzle to astronomers.

A conical stem of young plasma is seen being ejected from the centre and reaches far beyond the visible stars of RAD12. The GMRT observations revealed that the fainter and older plasma extends far beyond the central conical stem and flares out like the cap of a mushroom (seen in red in the tricolour image). The whole structure is 440 thousand light years long, which is much larger than the host galaxy itself.

RAD12 is unlike anything known so far; this is the first time a jet has been observed to collide with a large galaxy like RAD12-B. Astronomers are now one step closer to understanding the impact of such interactions on elliptical galaxies, which may leave them with little cold gas for future star formation.

Research lead Dr Ananda Hota says, "We are excited to have spotted a rare system that helps us understand radio jet feedback of supermassive black holes on star formation of galaxies during mergers.  Observations with the GMRT and data from various other telescopes such as the MeerKAT radio telescope strongly suggest that the radio jet in RAD12 is colliding with the companion galaxy. An equally important aspect of this research is the demonstration of public participation in making discoveries through the RAD@home Citizen Science research collaboratory."

Source: Royal Astronomical Society (RAS)

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Contacts:

Gurjeet Kahlon
Royal Astronomical Society
Mob: +44 (0)7802 877 700
press@ras.ac.uk

Dr Robert Massey
Royal Astronomical Society
Mob: +44 (0)7802 877699
press@ras.ac.uk

Science Contacts

Dr Ananda Hota
UM-DAE Centre for Excellence in Basic Sciences
RAD@home Astronomy Collaboratory
University of Mumbai hotaananda@gmail.com

Dr Pratik Dabhade
Observatoire de Paris (College de France)
pratikdabhade13@gmail.com

Dr Sravani Vaddi
Arecibo Observatory
sravani.vaddi@gmail.com

Ms Megha Rajoria
RAD@home Astronomy Collaboratory
megharajoria3@gmail.com

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Futher Information

The RAD@home Collaboratory welcomes collaboration with other astronomers for future investigation in multiple wavelength campaigns with multiple telescopes. The Collaboratory invites not only professional astronomers but also interested citizens with university-level science degrees to participate in this citizen Science research program. RAD12 Discovery is a beautiful example of how the public (particularly University science students) can directly participate in real astronomy discovery sitting at home.

Other than Dr Hota, Dr Dabhade and Dr Vaddi, the team includes astronomers Dr Chiranjib Konar (Amity University), Dr Sabyasachi Pal (Midnapore City College), Dr Mamta Gulati (Thapar Institute of Engineering and Technology), Dr C S. Stalin (Indian Institute of Astrophysics) and Mr Ck Avinash, Mr Avinash Kumar, Ms Megha Rajoria, Ms Arundhati Purohit from RAD@home Collaboratory.

The research appears in ‘RAD@home citizen science discovery of an AGN spewing a large unipolar radio bubble onto its merging companion galaxy’, Ananda Hota et al.,published in Monthly Notices of the Royal Astronomical Society, in press.

Animation: https://www.youtube.com/watch?v=BwnfUq5mCEE

Caption: Animation of an AGN (Active Galactic Nucleus) spewing a large unipolar radio bubble on to its merging companion galaxy.
Credit: Dr Ananda Hota, Dr Pratik Dabhade, Dr Sravani Vaddi

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Notes for Editors

The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognises outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4,000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.

The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.

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Multiwavelength View of a Turbulent Stellar Nursery

Image description: Two wispy, gaseous clouds occupy the corners of this image, HH 1 in the upper right, and HH 2 in the lower left. Both are light blue and surrounded by dimmer multi-coloured clouds, while the background is dark black due to dense gas. A very bright orange star lies just to the lower left of HH 1, and beyond that star is a narrow jet, emerging from the dark centre of the field. Credit: ESA/Hubble & NASA, B. Reipurth, B. Nisini.  Hi-res image

The lives of newborn stars are tempestuous, as this image of the Herbig–Haro objects HH 1 and HH 2 from the NASA/ESA Hubble Space Telescope depicts. Both objects are in the constellation Orion and lie around 1250 light-years from Earth. HH 1 is the luminous cloud above the bright star in the upper right of this image, and HH 2 is the cloud in the bottom left. While both Herbig–Haro objects are visible, the young star system responsible for their creation is lurking out of sight, swaddled in the thick clouds of dust at the centre of this image. However, an outflow of gas from one of these stars can be seen streaming out from the central dark cloud as a bright jet. Meanwhile, the bright star between that jet and the HH 1 cloud was once thought to be the source of these jets, but it is now known to be an unrelated double star that formed nearby.

Herbig–Haro objects are glowing clumps found around some newborn stars, and are created when jets of gas thrown outwards from these young stars collide with surrounding gas and dust at incredibly high speeds. In 2002 Hubble observations revealed that parts of HH 1 are moving at more than 400 kilometres per second!

This scene from a turbulent stellar nursery was captured with Hubble’s Wide Field Camera 3 using 11 different filters at infrared, visible, and ultraviolet wavelengths. Each of these filters is sensitive to just a small slice of the electromagnetic spectrum, and they allow astronomers to pinpoint interesting processes that emit light at specific wavelengths.

In the case of HH 1/2, two groups of astronomers requested Hubble observations for two different studies. The first delved into the structure and motion of the Herbig–Haro objects visible in this image, giving astronomers a better understanding of the physical processes occurring when outflows from young stars collide with surrounding gas and dust. The second study instead investigated the outflows themselves to lay the groundwork for future observations with the NASA/ESA/CSA James Webb Space Telescope. Webb, with its ability to peer past the clouds of dust enveloping young stars, will revolutionise the study of outflows from young stars.

[Image description: Two wispy, gaseous clouds occupy the corners of this image, HH 1 in the upper right, and HH 2 in the lower left. Both are light blue and surrounded by dimmer multi-coloured clouds, while the background is dark black due to dense gas. A very bright orange star lies just to the lower left of HH 1, and beyond that star is a narrow jet, emerging from the dark centre of the field.]

Link

• Video of Multiwavelength View of a Turbulent Stellar Nursery

Source: ESA/Hubble/potw 

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Cassiopeia A: NASA's IXPE Helps Unlock the Secrets of Famous Exploded Star

Cassiopeia A
Credit: X-ray: Chandra: NASA/CXC/SAO, IXPE: NASA/MSFC/J. Vink et al.; Optical: NASA/STScI

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For the first time, astronomers have measured and mapped polarized X-rays from the remains of an exploded star, using NASA’s Imaging X-ray Polarimetry Explorer (IXPE). The findings, which come from observations of a stellar remnant called Cassiopeia A, shed new light on the nature of young supernova remnants, which accelerate particles close to the speed of light.

Launched on Dec. 9, 2021, IXPE, a collaboration between NASA and the Italian Space Agency, is the first satellite that can measure the polarization of X-ray light with this level of sensitivity and clarity.

All forms of light — from radio waves to gamma rays — can be polarized. Unlike the polarized sunglasses we use to cut the glare from sunlight bouncing off a wet road or windshield, IXPE’s detectors maps the tracks of incoming X-ray light. Scientists can use these individual track records to figure out the polarization, which tells the story of what the X-rays went through.

Cassiopeia A (Cas A for short) was the first object IXPE observed after it began collecting data. One of the reasons Cas A was selected is that its shock waves — like a sonic boom generated by a jet — are some of the fastest in the Milky Way. The shock waves were generated by the supernova explosion that destroyed a massive star after it collapsed. Light from the blast swept past Earth more than three hundred years ago.

“Without IXPE, we have been missing crucial information about objects like Cas A,” said Pat Slane at the Center for Astrophysics | Harvard & Smithsonian, who leads the IXPE investigations of supernova remnants. “This result is teaching us about a fundamental aspect of the debris from this exploded star — the behavior of its magnetic fields.”

Magnetic fields, which are invisible, push and pull on moving charged particles like protons and electrons. Closer to home, they are responsible for keeping magnets stuck to a kitchen fridge. Under extreme conditions, such as an exploded star, magnetic fields can boost these particles to near-light-speed.

Despite their super-fast speeds, particles swept up by shock waves in Cas A do not fly away from the supernova remnant because they are trapped by magnetic fields in the wake of the shocks. The particles are forced to spiral around the magnetic field lines, and the electrons give off an intense kind of light called “synchrotron radiation,” which is polarized.

By studying the polarization of this light, scientists can “reverse engineer” what’s happening inside Cas A at very small scales — details that are difficult or impossible to observe in other ways. The angle of polarization tells us about the direction of these magnetic fields. If the magnetic fields close to the shock fronts are very tangled, the chaotic mix of radiation from regions with different magnetic field directions will give off a smaller amount of polarization.

Previous studies of Cas A with radio telescopes have shown that the radio synchrotron radiation is produced in regions across almost the entire supernova remnant. Astronomers found that only a small amount of the radio waves were polarized — about 5%. They also determined that the magnetic field is oriented radially, like the spokes of a wheel, spreading out from near the center of the remnant towards the edge.

Data from NASA’s Chandra X-ray Observatory, on the other hand, show that the X-ray synchrotron radiation mainly comes from thin regions along the shocks, near the circular outer rim of the remnant, where the magnetic fields were predicted to align with the shocks. Chandra and IXPE use different kinds of detectors and have different levels of angular resolution, or sharpness. Launched in 1999, Chandra’s first science image was also of Cas A.

Before IXPE, scientists predicted X-ray polarization would be produced by magnetic fields that are perpendicular to magnetic fields observed by radio telescopes.

Instead, IXPE data show that the magnetic fields in X-rays tend to be aligned in radial directions even very close to the shock fronts. The X-rays also reveal a lower amount of polarization than radio observations showed, which suggests that the X-rays come from turbulent regions with a mix of many different magnetic field directions.

Cassiopeia A Polarization Vectors
Credit: Chandra: NASA/CXC/SAO; IXPE: NASA/MSFC

"These IXPE results were not what we expected, but as scientists we love being surprised,” says Dr. Jacco Vink of the University of Amsterdam and lead author of the paper describing the IXPE results on Cas A. “The fact that a smaller percentage of the X-ray light is polarized is a very interesting — and previously undetected — property of Cas A.”

The IXPE result for Cas A is whetting the appetite for more observations of supernova remnants that are currently underway. Scientists expect each new observed object will reveal new answers — and pose even more questions — about these important objects that seed the Universe with critical elements.

“This study enshrines all the novelties that IXPE brings to astrophysics,” said Dr. Riccardo Ferrazzoli with the Italian National Institute for Astrophysics/Institute for Space Astrophysics and Planetology in Rome. “Not only did we obtain information on X-ray polarization properties for the first time for these sources, but we also know how these change in different regions of the supernova. As the first target of the IXPE observation campaign, Cas A provided an astrophysical 'laboratory' to test all the techniques and analysis tools that the team has developed in recent years.”

“These results provide a unique view of the environment necessary to accelerate electrons to incredibly high energies," said co-author Dmitry Prokhorov, also of the University of Amsterdam. “We are just at the beginning of this detective story, but so far the IXPE data are providing new leads for us to track down.”

IXPE is a collaboration between NASA and the Italian Space Agency with partners and science collaborators in 12 countries. Ball Aerospace, headquartered in Broomfield, Colorado, manages spacecraft operations together with the University of Colorado's Laboratory for Atmospheric and Space sciences, which operates IXPE for NASA’s Marshall Space Flight Center in Huntsville, Alabama.

Source: NASA’s Chandra X-ray Observatory

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Fast Facts for Cassiopeia A:

Scale: Main image is about 8.91 arcmin (29 light-years) across.
Category: Supernovas & Supernova Remnants
Coordinates (J2000): RA 23h 23m 26.7s | Dec +58° 49' 03.00"
Constellation: Cassiopeia
Observation Date: 16 pointings between Jan 2000-Nov 2010
Observation Time: 353 hours (14 days, 17 hours)
Obs. ID: 114, 1952, 4634-4639, 5196, 5319, 5320, 6690, 10935, 10936, 12020, 13177
Instrument: ACIS
Also Known As: Cas A
References: Vink, J. et al., 2022, ApJ, 938, 40; arXiv:2206.06713
Color Code: X-ray: Chandra (blue/cyan), IXPE (turquoise); Optical: gold;
Distance Estimate: About 11,000 light-years

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NASA’s Webb Takes Star-Filled Portrait of Pillars of Creation

Pillars of Creation (NIRCam Image)
Credits: Science: NASA, ESA, CSA, STScI
Image Processing: Joseph DePasquale (STScI), Anton M. Koekemoer (STScI), Alyssa Pagan (STScI)

Pillars of Creation (Hubble and Webb Images Side by Side)
Credits: Science: NASA, ESA, CSA, STScI, Hubble Heritage Project (STScI, AURA)
Image Processing: Joseph DePasquale (STScI), Anton M. Koekemoer (STScI), Alyssa Pagan (STScI)

Release Images | Release Videos

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NASA’s James Webb Space Telescope has captured a lush, highly detailed landscape – the iconic Pillars of Creation – where new stars are forming within dense clouds of gas and dust. The three-dimensional pillars look like majestic rock formations, but are far more permeable. These columns are made up of cool interstellar gas and dust that appear – at times – semi-transparent in near-infrared light.

Webb’s new view of the Pillars of Creation, which were first made famous when imaged by NASA’s Hubble Space Telescope in 1995, will help researchers revamp their models of star formation by identifying far more precise counts of newly formed stars, along with the quantities of gas and dust in the region. Over time, they will begin to build a clearer understanding of how stars form and burst out of these dusty clouds over millions of years.

Newly formed stars are the scene-stealers in this image from Webb’s Near-Infrared Camera (NIRCam). These are the bright red orbs that typically have diffraction spikes and lie outside one of the dusty pillars. When knots with sufficient mass form within the pillars of gas and dust, they begin to collapse under their own gravity, slowly heat up, and eventually form new stars.

What about those wavy lines that look like lava at the edges of some pillars? These are ejections from stars that are still forming within the gas and dust. Young stars periodically shoot out supersonic jets that collide with clouds of material, like these thick pillars. This sometimes also results in bow shocks, which can form wavy patterns like a boat does as it moves through water. The crimson glow comes from the energetic hydrogen molecules that result from jets and shocks. This is evident in the second and third pillars from the top – the NIRCam image is practically pulsing with their activity. These young stars are estimated to be only a few hundred thousand years old.

Although it may appear that near-infrared light has allowed Webb to “pierce through” the clouds to reveal great cosmic distances beyond the pillars, there are no galaxies in this view. Instead, a mix of translucent gas and dust known as the interstellar medium in the densest part of our Milky Way galaxy’s disk blocks our view of the deeper universe.

This scene was first imaged by Hubble in 1995 and revisited in 2014, but many other observatories have also stared deeply at this region. Each advanced instrument offers researchers new details about this region, which is practically overflowing with stars.

 

This tightly cropped image is set within the vast Eagle Nebula, which lies 6,500 light-years away.

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

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Credits:

Release: NASA, ESA, CSA, STScI

Media Contact:

Claire Blome
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Source: NASA's James Webb Space Telescope/News

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Record-Breaking Gamma-Ray Burst Possibly Most Powerful Explosion Ever Recorded

PR Image noirlab2224a

Record-breaking Gamma-Ray Burst Caught With Gemini

PR Image noirlab2224b

Record-breaking Gamma-Ray Burst Caught With Gemini (no annotations) 

 

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Near-simultaneous observations with Gemini South in Chile of GRB221009A thanks to rapid-response teams of observers and staff

In the early-morning hours of today, 14 October 2022, astronomers using the Gemini South telescope in Chile operated by NSF’s NOIRLab observed the unprecedented aftermath of one of the most powerful explosions ever recorded, Gamma-Ray Burst GRB221009A. This record-shattering event, which was first detected on 9 October 2022 by orbiting X-ray and gamma-ray telescopes, occurred 2.4 billion light-years from Earth and was likely triggered by a supernova explosion giving birth to a black hole.

A titanic cosmic explosion triggered a burst of activity from astronomers around the world as they raced to study the aftermath from what is one of the nearest and possibly the most-energetic gamma-ray burst (GRB) ever observed. Just-released observations by two independent teams using the Gemini South telescope in Chile — one of the twin telescopes of the International Gemini Observatory operated by NSF’s NOIRLab — targeted the bright, glowing remains of the explosion, which likely heralded a supernova giving birth to a black hole.

The GRB, identified as GRB 221009A, occurred approximately 2.4 billion light-years away in the direction of the constellation Sagitta. It was first detected the morning of 9 October by X-ray and gamma-ray space telescopes, including NASA's Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and the Wind spacecraft. 

As word of this detection quickly spread, two teams of astronomers worked closely with staff at the Gemini South to obtain the earliest-possible observations of the afterglow of this historic explosion. 

In the early-morning hours of Friday, 14 October, two Rapid Target of Opportunity imaging  observations [1] were conducted by two independent teams of observers led by graduate students Brendan O'Connor (University of Maryland/George Washington University) and Jillian Rastinejad (Northwestern University). The observations occurred mere minutes apart. The first observation used the FLAMINGOS-2 instrument, a near-infrared imaging spectrograph. The other observation used the Gemini Multi-Object Spectrograph (GMOS). 

The teams now have access to both datasets for their analyses of this energetic and evolving event. 

“The exceptionally long GRB 221009A is the brightest GRB ever recorded and its afterglow is smashing all records at all wavelengths,” said O'Connor. “Because this burst is so bright and also nearby, we think this is a once-in-a-century opportunity to address some of the most fundamental questions regarding these explosions, from the formation of black holes to tests of dark matter models.” 

Thanks to the fast reaction of observers and staff, combined with the use of Gemini Director's Discretionary Time and efficient data-reduction software like Gemini’s DRAGONS “FIRE" (Fast Initial Reduction Engine), this image was quickly produced soon after the observations.  

“The agility and responsiveness of Gemini’s infrastructure and staff are hallmarks of our observatory and have made our telescopes go-to resources for astronomers studying transient events,” said Gemini Chief Scientist Janice Lee.

Already communications have gone out to fellow astronomers through the NASA Gamma-ray Coordinates Network [2], the archive of which is now filling up with reports from around the world. Astronomers think it represents the collapse of a star many times the mass of our Sun, which in turn launches an extremely powerful supernova and gives  birth to a black hole 2.4 billion light-years from Earth. 

“In our research group, we’ve been referring to this burst as the ‘BOAT’, or Brightest Of All Time, because when you look at the thousands of bursts gamma-ray telescopes have been detecting since the 1990s, this one stands apart,” said Rastinejad. “Gemini’s sensitivity and diverse instrument suite will help us to observe GRB221009A’s  optical counterparts to much later times than most ground-based telescopes can observe. This will help us understand what made this gamma-ray burst so uniquely bright and energetic."

When black holes form, they drive powerful jets of particles that are accelerated to nearly the speed of light. These jets then piece through what remains of the progenitor star, emitting X-rays and gamma rays as they stream into space. If these jets are pointed in the general direction of Earth, they are observed as bright flashes of X-rays and gamma rays. 

Another gamma-ray burst this bright may not appear for decades or even centuries and the case is still evolving. Of note are other extraordinary reports of disturbances in the Earth’s ionosphere affecting long wave radio transmissions from the energetic radiation from the GRB221009A event. Scientists are also wondering how very-high-energy 18 TeV (tera-electron-volt) photons [3] observed with the Chinese Large High Altitude Air Shower Observatory could defy our standard understanding of physics and survive their 2.4 billion year journey to Earth. 

This event, because of its relative proximity to Earth, is also a unique opportunity to better understand the origin of the elements heavier than iron and whether they all come solely from neutron-star mergers or also from collapsing stars that trigger GRBs. 

“The Gemini observations will allow us to utilize this nearby event to the fullest and seek out the signatures of heavy elements formed and ejected in the massive star collapse,” said O’Connor.

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Notes

[1] The “Target of Opportunity” observing mode allows observation of targets that cannot be specified in advance but have a well defined external trigger. Examples include following up newly detected supernovae or gamma-ray burst afterglows or observing a particular class of objects from an ongoing imaging survey.

[2] Rapid short “telegram-style” communications from the two teams through the NASA Gamma-ray Coordinates Network from Jillian Rastinejad & W Fong (Northwestern Univ) on behalf of a larger collaboration and from Brendan O'Connor (UMD/GWU), E. Troja (UTV/ASU)), S. Dichiara (PSU), J. Gillanders (UTV), S. B. Cenko (NASA/GSFC).

[3] For comparison, the most powerful collision in the Large Hadron Collider at CERN so far had an energy of only 13 TeV.

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More Information

NSF’s NOIRLab (National Optical-Infrared Astronomy Research Laboratory), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O'odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

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Links

• NASA Gamma-ray Coordinates Network Circular 32749 (Jillian Rastinejad & W Fong (Northwestern Univ)): https://gcn.gsfc.nasa.gov/gcn3/32749.gcn3 
• NASA Gamma-ray Coordinates Network Circular 32750 (Brendan O'Connor (UMD/GWU) et al.): https://gcn.gsfc.nasa.gov/gcn3/32750.gcn3 
• Photos of the Gemini South telescope
• Videos of the Gemini South telescope

 

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Contacts:

Jillian Rastinejad
Northwestern University
Email: jillianrastinejad2024@u.northwestern.edu

Brendan O'Connor
University of Maryland/George Washington University
Email: oconnorb@umd.edu

Charles Blue
Public Information Officer
NSF’s NOIRLab
Tel: +1 202 236 6324
Email: charles.blue@noirlab.edu

 Source:  NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab)/News

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Abell 98: NASA's Chandra Finds Galaxy Cluster Collision on a "WHIM"

Abell 98
Credit: X-ray: NASA/CXC/CfA/A. Sarkar; Optical: NSF/NOIRLab/WIYN

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A Tour of Abell 98 -More Animations

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This image features Abell 98, a system of galaxy clusters that includes a pair in the early stages of a collision. Astronomers have used data from NASA’s Chandra X-ray Observatory (shown as blue and purple with optical data from the WIYN telescope on Kitt Peak in Arizona appearing white and red) to identify key structures and look for "missing" matter in the Universe.

This missing material is not dark matter, which is invisible, of an unknown nature, and thought to constitute most of the matter in the universe, but "normal" matter found in familiar objects like stars, planets, and humans. About a third of this matter that was created in the first billion years or so after the Big Bang has yet to be detected by observations of the local universe, that is, in regions less than a few billion light-years from Earth.

Scientists have proposed that at least some of this unaccounted-for mass could be hidden in gigantic strands, or filaments, of warm to hot (temperatures of 10,000 to 10 million Kelvin) gas in the space in between galaxies and clusters of galaxies. They have dubbed this the "warm-hot intergalactic medium," or WHIM.

A team of astronomers examined Chandra data of Abell 98, which is about 1.4 billion light-years from Earth, and said they have likely found evidence of this WHIM residing in the space between the two galaxy clusters. The Chandra data reveal a bridge of X-ray emission (shown in a labeled version) between two of the colliding clusters containing gas at a temperature of about 20 million Kelvin and relatively cooler gas with a temperature of about 10 million Kelvin. The hotter gas in the bridge is likely from gas in the two clusters overlapping with each other. The temperature and density of the cooler gas agree with predictions for the hottest and densest gas in the WHIM.

In addition, the Chandra data show the presence of a shock wave, which is similar to a sonic boom from a supersonic plane. The location of the shock wave is labeled and is identified by sudden decreases in the brightness of the X-rays and the gas temperature, measured from the northern to southern side of the shock. This shock wave is driven by and located ahead of one of the galaxy clusters as it is starting to collide with another cluster. This would be the first time that astronomers have found such a shock wave in the early stages of a galaxy cluster collision, before the centers of the cluster pass by one another. This shock wave may be directly connected to the discovery of the WHIM in Abell 98 because it has heated the gas in between the clusters as they collide. This may have raised the temperature of the gas in the WHIM filament — estimated to contain some 400 billion times the mass of the Sun — high enough to be detected with Chandra data.

Abell 98 (Labeled)
Credit: X-ray: NASA/CXC/CfA/A. Sarkar; Optical: NSF/NOIRLab/WIYN

A paper describing this result by Arnab Sarkar et al was published in The Astrophysical Journal Letters and is available at https://arxiv.org/abs/2208.03401. Other authors on the paper include Scott Randall (Center for Astrophysics | Harvard & Smithsonian), Yuanyuan Su (University of Kentucky), Gabriella E. Alvarez (CfA), Craig Sarazin (University of Virginia, Charlottesville, Virginia), Paul Nulsen (CfA), Elizabeth Blanton (Boston University, Boston, Massachusetts), William Forman (CfA), Christine Jones (CfA), Esra Bulbul (Max Planck Institute for Extraterrestrial Physics, Garching, Germany), John Zuhone (CfA), Felipe Andrade-Santos (CfA), Ryan Johnson (Gettysburg College, Gettysburg, Pennsylvania), and Priyanka Chakraborty (CfA).

Additional evidence for the WHIM filament between these two clusters was found with the Japan Aerospace Exploration Agency’s Suzaku, in a new paper led by Gabriella Alvarez, also of CfA. Their paper also gives evidence for the WHIM on the opposite side of the cluster that is leading the collision. (The general location and direction of this Suzaku-detected filament is labeled, but the filament itself is not visible in the Chandra data, despite the field of view extending further to the north than shown here.) These two detections of the WHIM indicate that the clusters are located along a colossal structure that is 13 million light-years long. The paper by Alvarez was recently accepted for publication in The Astrophysical Journal and is available at https://arxiv.org/abs/2206.08430.

NASA's Marshall Space Flight Center 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.

Quick Look: NASA's Chandra Finds Galaxy Cluster Collision on a "WHIM"

Source: NASA’s Chandra X-ray Observatory

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Fast Facts for Abell 98:

Scale: Image is about 6.14 arcmin (2.3 million light-years) across.
Category: Groups & Clusters of Galaxies
Coordinates (J2000): RA 00h 46m 30.78s | Dec +20° 30´ 11.45"
Constellation: Pisces
Observation Date: 10 Observations from Sep 17, 2009 to Feb 19, 2019
Observation Time: 63 hours 40 minutes (2 days 15 hours 40 minutes)
Obs. ID: 11876-11877, 21534-21535, 21856-21857, 21880, 21893-21895
Instrument: ACIS
References: Sarkar, A., et al., 2022, ApJL, 935, L23; arXiv:2208.03401
Color Code: X-ray: blue, purple; Optical: red, green, blue
Distance Estimate: About 1.36 billion light-years (z=0.104)

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