. 24/7 Space News .
Cosmic filaments exposed near huge cluster
by Staff Writers
Paris (ESA) Dec 03, 2015

Components of the galaxy cluster Abell 2744, also known as the Pandora Cluster: galaxies (white), hot gas (red) and dark matter (blue). Galaxy clusters are the most massive cosmic structures held together by gravity, consisting of galaxies, hot gas and dark matter. They sit in the densest hubs of the filamentary 'cosmic web' that pervades the Universe. Using ESA's XMM-Newton X-ray observatory, astronomers have detected three massive filaments flowing towards the core of Abell 2744 and connecting it with the cosmic web. The filaments also consist of galaxies, hot gas and dark matter. One of them can be seen as the elongated structure on the left side of the image, another one is visible towards the upper right, and the third one below the cluster, slightly towards the right. (These are indicated with ellipses in this image.) There are also two structures - one on the lower left of the cluster, the other in the upper central part of the image - which are not physically linked to the cluster but are the projection of more distant structures viewed along the same line of sight. The astronomers detected the hot gas in the cluster and filaments with X-ray observations and the galaxies with optical observations. To reconstruct the distribution of dark matter, they used the gravitational lensing effect that the mass of the cluster and filaments exerts on more distant galaxies. Abell 2744 has a mass of almost two million billion times the mass of our Sun. Light from the cluster galaxies and gas travelled for over 3 billion years to reach Earth. The image measures about half a degree across. The image is sprinkled with foreground stars belonging to our Galaxy, the Milky Way, which are visible as the roundish objects with diffraction spikes. Image courtesy ESA/XMM-Newton (X-rays); ESO/WFI (optical); NASA/ESA and CFHT (dark matter). For a larger version of this image please go here.

ESA's XMM-Newton X-ray observatory has revealed three massive filaments of hot gas flowing towards a cluster of galaxies, uncovering a portion of the cosmic skeleton that pervades the entire Universe.

Galaxies tend to congregate, forming groups and even larger agglomerates called clusters. These clusters are the most massive cosmic structures held together by gravity. As well as galaxies, they contain large amounts of hot gas and even larger amounts of invisible dark matter.

On a grander scale, galaxies and galaxy clusters appear to be linked in a gigantic filamentary network, with the most massive clusters sitting in the densest hubs of this 'cosmic web'.

Computer simulations indicate that the cosmic web, which consists primarily of dark matter and some ordinary matter, behaves as the scaffolding of the cosmos, providing the framework for stars, galaxies and clusters to form and evolve.

In the past few decades, astronomers have detected the threadlike structure of the cosmic web in the large-scale distribution of galaxies, and found hints that diffuse gas is arranged in a similar way.

A new study using ESA's XMM-Newton X-ray observatory has now uncovered a handful of filaments made of galaxies, gas and dark matter that are flowing towards one of the most massive galaxy clusters in the Universe, obtaining the first, unambiguous detection of gas in the cosmic web.

"This was an unexpected and most welcome discovery," says Dominique Eckert of the University of Geneva, Switzerland, lead author of the paper reporting the new results in the journal Nature this week.

The object of the study is Abell 2744, which has been nicknamed the Pandora Cluster owing to its complex and jumbled structure. It is composed of at least four smaller components that are merging.

"We knew that this is an incredibly massive cluster hosting active processes at its core, and seeing its direct connection to the cosmic web confirms our picture of how structures form in the Universe," adds Dr Eckert.

From 30 hours of observations by XMM-Newton in December 2014, the astronomers detected five large structures of hot gas that seem to be linked to the core of Abell 2744.

Comparing the X-ray data with optical observations, they identified the galaxies that belong to the various filaments, recognising that three of them are physically connected to the cluster, while the other two are the projection of more distant structures viewed along the same line of sight.

Just like the cluster, the filaments also contain plenty of dark matter. The astronomers have reconstructed its distribution by studying the 'gravitational lensing' effect that the mass of the cluster and filaments exerts on distant galaxies, modifying the path of their light and so increasing their brightness and twisting their shapes as seen by us.

"We initially looked at the inner core of Abell 2744 with the Hubble Space Telescope, with the aim of using the cluster as a strong magnifying lens to detect background galaxies that would be otherwise too faint to observe," explains co-author Mathilde Jauzac from the University of Durham, UK.

"After the discovery of X-ray gas in these filaments, we decided to look at the gravitational lensing effect also in the outskirts of the cluster, where background galaxies are only weakly distorted and magnified, but still enable us to study the dark matter distribution near the cluster as well as in the nearby filaments."

The combination of observations at different wavelengths revealed how the various components of Abell 2744 and its surroundings coexist.

From the X-ray data, the astronomers measured the density and temperature of the gas and compared it with the predictions from theory. With gas temperatures of 10-20 million degrees celsius, the filaments are much colder than the centre of the cluster, where the gas reaches 100 million degrees, but hotter than the average temperature in the cosmic web, estimated to be several million degrees.

The gas and galaxies in the filaments amount to about a tenth of the total mass - the rest being dark matter - which also agrees with expectations.

While the measurements match well with the astronomers' theoretical scenario, caution is always in order when drawing conclusions about the Universe as a whole.

"What we observed is a very special configuration of dense filaments close to an exceptionally massive cluster. We need a much larger sample of less-dense filaments to investigate the nature of the cosmic web in greater detail," says Dr Eckert.

For more in-depth investigations, astronomers will have to wait for ESA's Athena X-ray telescope, planned for launch in 2028. Athena's extraordinary sensitivity will make it possible to survey hot gas in the cosmic web across the sky, detecting faint and diffuse filaments and even identifying some of the atomic elements in the gas.

"With the discovery of filaments around Abell 2744, we are witnessing the build-up of the cosmic web in one of the busiest places in the known Universe, a crucial step in the study of the formation of galaxies and galaxy clusters," says Norbert Schartel, ESA XMM-Newton Project Scientist.

"Warm-hot baryons comprise 5-10 per cent of filaments in the cosmic web," by D. Eckert et al. is published in the 3 December 2015 issue of the journal Nature.

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only


Related Links
XMM-Newton at ESA
Understanding Time and Space

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
Machine learning could solve riddles of galaxy formation
Champaign IL (SPX) Nov 15, 2015
A new machine-learning simulation system developed at the University of Illinois promises cosmologists an expanded suite of galaxy models - a necessary first step to developing more accurate and relevant insights into the formation of the universe. The feasibility of this method has been laid out in two recent papers written by astronomy, physics and statistics professor Robert Brunner, hi ... read more

Gaia's sensors scan a lunar transit

SwRI scientists explain why moon rocks contain fewer volatiles than Earth's

All-female Russian crew starts Moon mission test

Russian moon mission would need 4 Angara-A5V launches

ExoMars has historical, practical significance for Russia, Europe

European payload selected for ExoMars 2018 surface platform

ExoMars prepares to leave Europe for launch site

Tracking down the 'missing' carbon from the Martian atmosphere

Orion's power system to be put to the test

The Ins and Outs of NASA's First Launch of SLS and Orion

Aerojet Rocketdyne tapped for spacecraft's crew module propulsion

Brits Aim for the Stars with Big Bucks on Offer to Conquer Final Frontier

China launches Yaogan-29 remote sensing satellite

China's indigenous SatNav performing well after tests

China's scientific satellites to enter uncharted territory

China to launch Dark Matter Satellite in mid-December

Getting Into the Flow on the ISS

Russian-US Space Collaboration Intact Despite Chill in Bilateral Ties

ISS EarthKAM ready for student imaging request

Partners in Science: Private Companies Conduct Valuable Research on the Space Station

"Cyg"-nificant Science Launching to Space Station

Aerojet Rocketdyne completes AJ60 solid booster for Atlas V launcher

Flight teams prepare for LISA Pathfinder liftoff

Rocket launch demonstrates new capability for testing technologies

Neptune-size exoplanet around a red dwarf star

Exiled exoplanet likely kicked out of star's neighborhood

Retro Exo and Its Originators

How DSCOVR Could Help in Exoplanet Hunting

Creating a new vision for multifunctional materials

Cryogenic testing from 1964 to the James Webb Space Telescope

SSL selected to provide new high throughput satellite to Telesat

Satellite Spectrum Is Central To Future Vision For Global Connectivity

The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.