ESA's Euclid celebrates first science with sparkling cosmic views

This image of the spiral galaxy NGC 6744 is released as part of the Early Release Observations from ESA’s Euclid space mission. It’s a typical example of the type of galaxy currently forming most of the stars in the nearby Universe, making it a wonderful archetype to study with Euclid. © Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi; CC BY-SA 3.0 IGO or ESA Standard Licence.

In this image the faint diffuse emission around the center of the Perseus galaxy cluster has been highlighted in black and white. Even though this ‘intra-cluster light’ is much fainter than the bright cluster galaxies it contributes 20% to the overall luminosity. © Euclid consortium, MPE

Some dwarf galaxies survive the strong tidal forces in the Perseus galaxy cluster, shown here as zoom-ins. In total, the Euclid researchers found 1100 dwarf galaxies, many are much fainter than ever seen before in the Perseus galaxy cluster. © Euclid consortium, LMU, MPE

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Analysis of the early release observations provides insights into the evolution of the Perseus galaxy cluster

Today, ESA’s Euclid space mission releases five unprecedented new views of the Universe. The never-before-seen images demonstrate Euclid’s ability to unravel the secrets of the cosmos and enable scientists to hunt for rogue planets, use lensed galaxies to study mysterious matter, and explore the evolution of the Universe. The new images accompany the mission’s first scientific data, also made public today, and several science papers, including one led by the Max Planck Institute for Extraterrestrial Physics in Garching, with an unprecedented analysis of the faint intra-cluster light of the Perseus cluster of galaxies.

The full set of Euclid’s early observations targeted 17 astronomical objects, from nearby clouds of gas and dust to distant clusters of galaxies, ahead of Euclid’s main survey. Euclid will trace the hidden web-like foundations of the cosmos, map billions of galaxies across more than one-third of the sky, explore how our Universe formed and evolved over cosmic history, and study the most mysterious of its fundamental components: dark energy and dark matter.

While visually stunning, the images are far more than beautiful snapshots; they reveal new physical properties of the Universe thanks to Euclid’s novel and unique observing capabilities. These scientific secrets are detailed further in a number of accompanying papers released by the Euclid collaboration, together with five key reference papers about the Euclid mission (see link to the ESA press release on the left). Euclid produced this early catalogue in just a single day, revealing over 11 million objects in visible light and 5 million more in infrared light.

Euclid’s image of the Perseus cluster of galaxies was published as one of the first images of the space telescope, just six months ago. Perseus is one of the most spectacular objects in our cosmic neighborhood: It is located at a distance of “only” 240 million light years (at a redshift of z = 0.018) and is the brightest X-ray cluster. With its high total mass of 650 trillion solar masses, its gravity ties thousands of galaxies together.

For the first time, a team led by the Max Planck Institute for Extraterrestrial Physics (MPE) has now been able to analyze the diffuse light from the Perseus galaxy cluster to far-out regions. “The high sensitivity at optical and near-infrared wavelengths over a huge field of view allows us to capture the extended faint light in the Perseus cluster,” says Matthias Kluge, lead author of the study, which is now being published together with 14 other papers. “This light is more than 100,000 times fainter in the infrared than the darkest night sky on Earth. Nevertheless, due to its large volume, it accounts for about 20% of the luminosity of the entire cluster.”

In addition, the team also used Euclid's excellent visible light imaging capabilities - comparable to the Hubble Space Telescope - to detect 50,000 free-flying globular clusters. The characteristics of the globular clusters and the bluish color of the diffuse light indicate their common origin: On the one hand, they originate from the low-metallicity outer regions of massive cluster galaxies that have been stripped away by the tidal forces of the cluster. On the other hand, there is an increasing contribution of dwarf galaxies, which were also completely torn apart by the strong tidal forces, with increasing distance from the cluster center.

In a further study, numerous surviving dwarf galaxies were detected in the Perseus cluster. Raphael Zöller from MPE and LMU was significantly involved in the measurements: “Euclid is located at the second Lagrange point far outside the Earth's atmosphere. Thanks to the dark image background, the excellent image resolution and the large field of view, we were able to detect 1100 dwarf galaxies, including hundreds with much fainter luminosity than ever before in the Perseus galaxy cluster.”

Background information

Euclid is a space mission of the European Space Agency (ESA) with contributions from the National Aeronautics and Space Administration (NASA). It is the second M-class mission in ESA's Cosmic Vision programme.

VIS and NISP were developed and built by a consortium of scientists and engineers from 17 countries, many from Europe, but also from the USA, Canada and Japan. From Germany, the Max Planck Institute for Astronomy (MPIA) in Heidelberg, the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, the Ludwig Maximilian University (LMU) in Munich, the University of Bonn (UB), the Ruhr University Bochum (RUB) and the German Space Agency at the German Aerospace Centre (DLR) in Bonn are participating. As partner of the Euclid project, MPE is responsible for the optical components of the NISP instrument as well as for the optical design and modelling of the image quality and is hosting one of Euclid's nine Science Data Centers.

The German Space Agency at DLR coordinates the German ESA contributions and also provides funding of 60 million euros from the National Space Programme for the participating German research institutes.

With around 21%, Germany is the largest contributor to the ESA science programme.

Source: Max Planck Institute for Extraterrestrial Physics (MPE)

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Contacts:

Matthias Kluge
postdoc
tel:+49 89 30000-3576
fax:+49 89 30000-
mkluge@mpe.mpg.de

Raphael Zöller
phd student
fax:+49 89-
rzoeller@mpe.mpg.de

Ralf Bender
director
tel:+49 89 30000-3702
fax:+49 89 30000-3351
bender@mpe.mpg.de

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Original publications with main contributions from authors at MPE

(public on 24.05.2024)

1. M. Kluge et al.
Euclid: Early Release Observations – The intracluster light and intracluster globular clusters of the Perseus cluster
submitted

Source

2. Marleau et al.
Euclid: Early Release Observations – Dwarf galaxies in the Perseus galaxy cluster
submitted

Source

3. Cuillandre et al.
Euclid: Early Release Observations – Programme overview and pipeline for compact- and diffuse-emission photometry
submitted

Source

4. Cuillandre et al.

Euclid: Early Release Observations – Overview of the Perseus cluster and analysis of its luminosity & stellar mass functions submitted

Source:

5. Atek et al.
Euclid: Early Release Observations – A preview of the Euclid era through a magnifying lens
submitted

Source

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More Information

Euclid @ MPE

Information on Euclid at ESA

ESA's Euclid celebrates first science with sparkling cosmic views

ESA Press Release with further images, information and Iinks

LMU Press Release

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A Bent Radio Jet in a Galaxy Cluster

This stunning composite image (click for the full view!) reveals the radio emission (shown in red) from a bent jet that was launched from the galaxy NGC 1272, the bright source just to the right of the image center. The 12’ x 12’ image of the Perseus galaxy cluster is captured by the Sloan Digital Sky Survey; the brightest central galaxy of the cluster, NGC 1275, can be seen to NGC 1272’s left. A new publication led by Marie-Lou Gendron-Marsolais (European Southern Observatory) presents high-resolution Very Large Array images of the detailed radio structures in the Perseus cluster. The authors use these new data to study how the galaxy’s movement as it falls into the cluster, as well as the bulk motions of the intracluster gas, shape the powerful radio jet into the dramatic shapes we see here. For more information, check out the original article below. Hi-res Image

Citation

“VLA Resolves Unexpected Radio Structures in the Perseus Cluster of Galaxies,” M.-L. Gendron-Marsolais et al 2021 ApJ 911 56. doi:10.3847/1538-4357/abddbb

By Susanna Kohler

 Source: American Astronomical Society - ASS (NOVA)

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Hitomi Mission Glimpses Cosmic 'Recipe' for the Nearby Universe

The Perseus galaxy cluster, located about 240 million light-years away, is shown in this composite of visible light (green and red) and near-infrared images from the Sloan Digital Sky Survey. Unseen here is a thin, hot, X-ray-emitting gas that fills the cluster. Credit: Robert Lupton and the Sloan Digital Sky Survey Consortium.  Hi-res image

 

Hitomi's Soft X-ray Spectrometer (SXS) instrument captured data from two overlapping areas of the Perseus galaxy cluster (blue outlines, upper right) in February and March 2016. The resulting spectrum has 30 times the detail of any previously captured, revealing many X-ray peaks associated with chromium, manganese, nickel and iron. Dark blue lines in the insets indicate the actual X-ray data points and their uncertainties.Credits: NASA's Goddard Space Flight Center. Hi-res image

 

Illustration of Hitomi, an X-ray astronomy observatory

Credits: Japan Aerospace Exploration Agency (JAXA).  Hi-res image

The Soft X-ray Spectrometer (SXS) on Hitomi, photographed Nov. 27, 2015, at Tsukuba Space Center in Japan. The SXS permitted scientists to observe the detailed motions and chemical composition of gas permeating the Perseus galaxy cluster. Credits: JAXA.  Hi-res image

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Before its brief mission ended unexpectedly in March 2016, Japan's Hitomi X-ray observatory captured exceptional information about the motions of hot gas in the Perseus galaxy cluster. Now, thanks to unprecedented detail provided by an instrument developed jointly by NASA and the Japan Aerospace Exploration Agency (JAXA), scientists have been able to analyze more deeply the chemical make-up of this gas, providing new insights into the stellar explosions that formed most of these elements and cast them into space.

The Perseus cluster, located 240 million light-years away in its namesake constellation, is the brightest galaxy cluster in X-rays and among the most massive near Earth. It contains thousands of galaxies orbiting within a thin hot gas, all bound together by gravity. The gas averages 90 million degrees Fahrenheit (50 million degrees Celsius) and is the source of the cluster's X-ray emission.

Using Hitomi's high-resolution Soft X-ray Spectrometer (SXS) instrument, researchers observed the cluster between Feb. 25 and March 6, 2016, acquiring a total exposure of nearly 3.4 days. The SXS observed an unprecedented spectrum, revealing a landscape of X-ray peaks emitted from various chemical elements with a resolution some 30 times better than previously seen.

In a paper published online in the journal Nature on Nov. 13, the science team shows that the proportions of elements found in the cluster are nearly identical to what astronomers see in the Sun.

"There was no reason to expect that initially," said coauthor Michael Loewenstein, a University of Maryland research scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "The Perseus cluster is a different environment with a different history from our Sun's. After all, clusters represent an average chemical distribution from many types of stars in many types of galaxies that formed long before the Sun.

One group of elements is closely tied to a particular class of stellar explosion, called Type Ia supernovas. These blasts are thought to be responsible for producing most of the universe's chromium, manganese, iron and nickel — metals collectively known as "iron-peak" elements.

Type Ia supernovas entail the total destruction of a white dwarf, a compact remnant produced by stars like the Sun. Although stable on its own, a white dwarf can undergo a runaway thermonuclear explosion if it's paired with another object as part of a binary system. This occurs either by merging with a companion white dwarf or, when paired with a nearby normal star, by stealing some of partner's gas. The transferred matter can accumulate on the white dwarf, gradually increasing its mass until it becomes unstable and explodes.

An important open question has been whether the exploding white dwarf is close to this stability limit — about 1.4 solar masses — regardless of its origins. Different masses produce different amounts of iron-peak metals, so a detailed tally of these elements over a large region of space, like the Perseus galaxy cluster, could indicate which kinds of white dwarfs blew up more often.

"It turns out you need a combination of Type Ia supernovas with different masses at the moment of the explosion to produce the chemical abundances we see in the gas at the middle of the Perseus cluster," said Hiroya Yamaguchi, the paper's lead author and a UMD research scientist at Goddard. "We confirm that at least about half of Type Ia supernovas must have reached nearly 1.4 solar masses." 

Taken together, the findings suggest that the same combination of Type Ia supernovas producing iron-peak elements in our solar system also produced these metals in the cluster's gas. This means both the solar system and the Perseus cluster experienced broadly similar chemical evolution, suggesting that the processes forming stars — and the systems that became Type Ia supernovas — were comparable in both locations. 

"Although this is just one example, there’s no reason to doubt that this similarity could extend beyond our Sun and the Perseus cluster to other galaxies with different properties," said coauthor Kyoko Matsushita, a professor of physics at the Tokyo University of Science.  

Although short-lived, the Hitomi mission and its revolutionary SXS instrument —developed and built by Goddard scientists working closely with colleagues from several institutions in the United States, Japan and the Netherlands — have demonstrated the promise of high-resolution X-ray spectrometry. 

"Hitomi has permitted us to delve deeper into the history of one of the largest structures in the universe, the Perseus galaxy cluster, and explore how particles and materials behave in the extreme conditions there," said Goddard's Richard Kelley, the U.S. principal investigator for the Hitomi collaboration. "Our most recent calculations have provided a glimpse into how and why certain chemical elements are distributed throughout galaxies beyond our own."

JAXA and NASA scientists are now working to regain the science capabilities lost in the Hitomi mishap by collaborating on the X-ray Astronomy Recovery Mission (XARM), expected to launch in 2021. One of its instruments will have capabilities similar to the SXS flown on Hitomi.

Hitomi launched on Feb. 17, 2016, and suffered a mission-ending spacecraft anomaly 38 days later. Hitomi, which translates to "pupil of the eye," was known before launch as ASTRO-H. The mission was developed by the Institute of Space and Astronautical Science, a division of JAXA. It was built jointly by an international collaboration led by JAXA, with contributions from Goddard and other institutions in the United States, Japan, Canada and Europe.

For more information about ASTRO-H, visit:  http://www.nasa.gov/astro-h​

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By Raleigh McElvery and Francis Reddy
NASA's Goddard Space Flight Center, Greenbelt, Md.

Editor: Rob Garner

Source: NASA/Hitomi

NASA's Fermi Mission Expands its Search for Dark Matter

Top: Gamma rays (magenta lines) coming from a bright source like NGC 1275 in the Perseus galaxy cluster should form a particular type of spectrum (right). Bottom: Gamma rays convert into hypothetical axion-like particles (green dashes) and back again when they encounter magnetic fields (gray curves). The resulting gamma-ray spectrum ((lower curve at right) would show unusual steps and gaps not seen in Fermi data, which means a range of these particles cannot make up a portion of dark matter. Credits: SLAC National Accelerator Laboratory/Chris Smith. Download additional visuals at NASA's Scientific Visualization Studio

Dark matter, the mysterious substance that constitutes most of the material universe, remains as elusive as ever. Although experiments on the ground and in space have yet to find a trace of dark matter, the results are helping scientists rule out some of the many theoretical possibilities. Three studies published earlier this year, using six or more years of data from NASA's Fermi Gamma-ray Space Telescope, have broadened the mission's dark matter hunt using some novel approaches.

“We've looked for the usual suspects in the usual places and found no solid signals, so we've started searching in some creative new ways," said Julie McEnery, Fermi project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "With these results, Fermi has excluded more candidates, has shown that dark matter can contribute to only a small part of the gamma-ray background beyond our galaxy, the Milky Way, and has produced strong limits for dark matter particles in the second-largest galaxy orbiting it."

Dark matter neither emits nor absorbs light, primarily interacts with the rest of the universe through gravity, yet accounts for about 80 percent of the matter in the universe. Astronomers see its effects throughout the cosmos -- in the rotation of galaxies, in the distortion of light passing through galaxy clusters, and in simulations of the early universe, which require the presence of dark matter to form galaxies at all.

The leading candidates for dark matter are different classes of hypothetical particles. Scientists think gamma rays, the highest-energy form of light, can help reveal the presence of some of types of proposed dark matter particles. Previously, Fermi has searched for tell-tale gamma-ray signals associated with dark matter in the center of our galaxy and in small dwarf galaxies orbiting our own.

Although no convincing signals were found, these results eliminated candidates within a specific range of masses and interaction rates, further limiting the possible characteristics of dark matter particles.

Among the new studies, the most exotic scenario investigated was the possibility that dark matter might consist of hypothetical particles called axions or other particles with similar properties. An intriguing aspect of axion-like particles is their ability to convert into gamma rays and back again when they interact with strong magnetic fields. These conversions would leave behind characteristic traces, like gaps or steps, in the spectrum of a bright gamma-ray source.

Manuel Meyer at Stockholm University led a study to search for these effects in the gamma rays from NGC 1275, the central galaxy of the Perseus galaxy cluster, located about 240 million light-years away. High-energy emissions from NGC 1275 are thought to be associated with a supermassive black hole at its center. Like all galaxy clusters, the Perseus cluster is filled with hot gas threaded with magnetic fields, which would enable the switch between gamma rays and axion-like particles. This means some of the gamma rays coming from NGC 1275 could convert into axions -- and potentially back again -- as they make their way to us.

"While we don't yet know what dark matter is, our results show we can probe axion-like models and provide the strongest constraints to date for certain masses," Meyer said. "Remarkably, we reached a sensitivity we thought would only be possible in a dedicated laboratory experiment, which is quite a testament to Fermi."

Another broad class of dark matter candidates are called Weakly Interacting Massive Particles (WIMPs). In some versions, colliding WIMPs either mutually annihilate or produce an intermediate, quickly decaying particle. Both scenarios result in gamma rays that can be detected by the LAT.

Regina Caputo at the University of California, Santa Cruz, sought these signals from the Small Magellanic Cloud (SMC), which is located about 200,000 light-years away and is the second-largest of the small satellite galaxies orbiting the Milky Way. Part of the SMC's appeal for a dark matter search is that it lies comparatively close to us and its gamma-ray emission from conventional sources, like star formation and pulsars, is well understood. Most importantly, astronomers have high-precision measurements of the SMC's rotation curve, which shows how its rotational speed changes with distance from its center and indicates how much dark matter is present. In a paper published in Physical Review D on March 22, Caputo and her colleagues modeled the dark matter content of the SMC, showing it possessed enough to produce detectable signals for two WIMP types.

The Small Magellanic Cloud (SMC), at center, is the second-largest satellite galaxy orbiting our own. This image superimposes a photograph of the SMC with one half of a model of its dark matter (right of center). Lighter colors indicate greater density and show a strong concentration toward the galaxy's center. Ninety-five percent of the dark matter is contained within a circle tracing the outer edge of the model shown. In six years of data, Fermi finds no indication of gamma rays from the SMC's dark matter. Credits: Dark matter, R. Caputo et al. 2016; background, Axel Mellinger, Central Michigan University

"The LAT definitely sees gamma rays from the SMC, but we can explain them all through conventional sources," Caputo said. "No signal from dark matter annihilation was found to be statistically significant."

In the third study, researchers led by Marco Ajello at Clemson University in South Carolina and Mattia Di Mauro at SLAC National Accelerator Laboratory in California took the search in a different direction. Instead of looking at specific astronomical targets, the team used more than 6.5 years of LAT data to analyze the background glow of gamma rays seen all over the sky.

The nature of this light, called the extragalactic gamma-ray background (EGB) has been debated since it was first measured by NASA's Small Astronomy Satellite 2 in the early 1970s. Fermi has shown that much of this light arises from unresolved gamma-ray sources, particularly galaxies called blazars, which are powered by material falling toward gigantic black holes. Blazars constitute more than half of the total gamma-ray sources seen by Fermi, and they make up an even greater share in a new LAT catalog of the highest-energy gamma rays.

This animation switches between two images of the gamma-ray sky as seen by Fermi's Large Area Telescope (LAT), one using the first three months of LAT data, the other showing a cumulative exposure of seven years. The blue color, representing the fewest gamma rays, includes the extragalactic gamma-ray background. Blazars make up most of the bright sources shown (colored red to white). With increasing exposure, Fermi reveals more of them. A new study shows blazars are almost completely responsible for the background glow.Credits: NASA/DOE/Fermi LAT Collaboration

Some models predict that EGB gamma rays could arise from distant interactions of dark matter particles, such as the annihilation or decay of WIMPs. In a detailed analysis of high-energy EGB gamma rays, published April 14 in Physical Review Letters, Ajello and his team show that blazars and other discrete sources can account for nearly all of this emission.

"There is very little room left for signals from exotic sources in the extragalactic gamma-ray background, which in turn means that any contribution from these sources must be quite small," Ajello said. "This information may help us place limits on how often WIMP particles collide or decay."

Although these latest studies have come up empty-handed, the quest to find dark matter continues both in space and in ground-based experiments. Fermi is joined in its search by NASA's Alpha Magnetic Spectrometer, a particle detector on the International Space Station.

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

For more information about NASA's Fermi Gamma-ray Space Telescope, visit:  www.nasa.gov/fermi

By Francis Reddy
NASA's Goddard Space Flight Center, Greenbelt, Md.

Editor: Ashley Morrow

 Source: NASA/Dark Energy/Matter

Puzzling X-rays point to dark matter

Perseus galaxy cluster

Copyright: Chandra: NASA/CXC/SAO/E.Bulbul, et al.; XMM: ESA)

A new study of the Perseus galaxy cluster, shown in this image, and others using Chandra and XMM-Newton has revealed a mysterious X-ray signal in the data. The signal is also seen in over 70 other galaxy clusters using XMM-Newton. This unidentified signal requires further investigation to confirm both its existence and nature, but one possibility is that it represents the decay of ‘sterile neutrinos’, one proposed candidate to explain dark matter.

Mysterious signal in the Perseus galaxy cluster
Copyright: NASA/CXC/SAO/E.Bulbul, et al.

A new study of the Perseus galaxy cluster, shown in this image, and others using Chandra and XMM-Newton has revealed a mysterious X-ray signal in the data. This signal is represented in the circled data points in the inset, which is a plot of X-ray intensity as a function of X-ray energy. The signal is also seen in over 70 other galaxy clusters using XMM-Newton. This unidentified X-ray emission line – a spike of intensity centred on about 3.56 keV – requires further investigation to confirm both the signal’s existence and nature. One possibility is this signal is the decay of ‘sterile neutrinos’, one proposed candidate to explain dark matter.

Astronomers using ESA and NASA high-energy observatories have discovered a tantalising clue that hints at an elusive ingredient of our Universe: dark matter. 

Although thought to be invisible, neither emitting nor absorbing light, dark matter can be detected through its gravitational influence on the movements and appearance of other objects in the Universe, such as stars or galaxies. 

Based on this indirect evidence, astronomers believe that dark matter is the dominant type of matter in the Universe – yet it remains obscure. 

Now a hint may have been found by studying galaxy clusters, the largest cosmic assemblies of matter bound together by gravity. 

Galaxy clusters not only contain hundreds of galaxies, but also a huge amount of hot gas filling the space between them. 

However, measuring the gravitational influence of such clusters shows that the galaxies and gas make up only about a fifth of the total mass – the rest is thought to be dark matter. 

The gas is mainly hydrogen and, at over 10 million degrees celsius, is hot enough to emit X-rays. Traces of other elements contribute additional X-ray ‘lines’ at specific wavelengths. 

Examining observations by ESA’s XMM-Newton and NASA’s Chandra spaceborne telescopes of these characteristic lines in 73 galaxy clusters, astronomers stumbled on an intriguing faint line at a wavelength where none had been seen before.  

“If this strange signal had been caused by a known element present in the gas, it should have left other signals in the X-ray light at other well-known wavelengths, but none of these were recorded,” says Dr Esra Bulbul from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, USA, lead author of the paper discussing the results. 

“So we had to look for an explanation beyond the realm of known, ordinary matter.” 

The astronomers suggest that the emission may be created by the decay of an exotic type of subatomic particle known as a ‘sterile neutrino’, which is predicted but not yet detected. 

Ordinary neutrinos are very low-mass particles that interact only rarely with matter via the so-called weak nuclear force as well as via gravity. Sterile neutrinos are thought to interact with ordinary matter through gravity alone, making them a possible candidate as dark matter.  

“If the interpretation of our new observations is correct, at least part of the dark matter in galaxy clusters could consist of sterile neutrinos,” says Dr Bulbul. 

 The surveyed galaxy clusters lie at a wide range of distances, from more than a hundred million light-years to a few billion light-years away. The mysterious, faint signal was found by combining multiple observations of the clusters, as well as in an individual image of the Perseus cluster, a massive structure in our cosmic neighbourhood. 

The implications of this discovery may be far-reaching, but the researchers are being cautious. Further observations with XMM-Newton, Chandra and other high-energy telescopes of more clusters are needed before the connection to dark matter can be confirmed. 

“The discovery of these curious X-rays was possible thanks to the large XMM-Newton archive, and to the observatory’s ability to collect lots of X-rays at different wavelengths, leading to this previously undiscovered line,” comments Norbert Schartel, ESA’s XMM-Newton Project Scientist. 

“It would be extremely exciting to confirm that XMM-Newton helped us find the first direct sign of dark matter. 

“We aren't quite there yet, but we’re certainly going to learn a lot about the content of our bizarre Universe while getting there.” 

More information

 

“Detection of an unidentified emission line in the stacked X-ray spectrum of galaxy clusters,” by E. Bulbul et al. is published in the 1 July 2014 issue of the Astrophysical Journal. 

For further information, please contact:

 

Markus Bauer 



ESA Science and Robotic Exploration Communication Officer




Tel: +31 71 565 6799





Mob: +31 61 594 3 954





Email: markus.bauer@esa.int




Esra Bulbul
Harvard-Smithsonian Center for Astrophysics
Cambridge, MA, USA
Phone: +1-617-496-7565
Email: ebulbul@cfa.harvard.edu

Norbert Schartel




XMM-Newton Project Scientist




Tel: +34 91 8131 184




Email: Norbert.Schartel@sciops.esa.int

Source: ESA