These pictures of the galaxy cluster Abell 1775 reveal X-rays from Chandra, optical information from the Pan-STARRS telescope in Hawaii, and radio information from the LOw Frequency Variety (LOFAR) in the Netherlands. A tail from the merged cluster is seen, together with an area of gas with a curved edge, called a “cold front”, that is denser and cooler than the gas it is raking into (see identified variation). The tail and the cold front all curve in the very same instructions, producing a spiral look. These functions are the outcome of 2 galaxy clusters — the biggest structures held together by gravity — crashing into one another, among the most energetic occasions in the Universe. Credit: X-ray: NASA/CXC/Leiden Univ./A. Botteon et al.; Radio: LOFAR/ASTRON; Optical/IR: PanSTARRS
- Abell 1775 is a system where a smaller sized galaxy cluster has actually raked into a bigger one.
- Using X-rays from Chandra and information from other telescopes astronomers are piecing together information of this crash.
- Features in the information, consisting of a curving tail of hot gas and a “cold front,” are hints.
- Scientists will likely require more observations and modeling to get the complete photo of Abell 1775.
When the titans of area — galaxy clusters — clash, remarkable things can take place. A brand-new research study utilizing NASA’s Chandra X-ray Observatory analyzes the effects after 2 galaxy clusters clashed.
Galaxy clusters are the biggest structures in the Universe held together by gravity, consisting of hundreds or perhaps countless specific galaxies immersed in huge oceans of superheated gas. In galaxy clusters, the regular matter — like the atoms that comprise the stars, worlds, and whatever on Earth — is mainly in the type of hot gas and stars. The mass of the hot gas in between the galaxies is far higher than the mass of the stars in all of the galaxies. This regular matter is bound in the cluster by the gravity of an even higher mass of dark matter.
Because of the substantial masses and speeds included, accidents and mergers in between galaxy clusters are amongst the most energetic occasions in the Universe.
In a brand-new research study of the galaxy cluster Abell 1775, situated about 960 million light-years from Earth, a group of astronomers led by Andrea Botteon from Leiden University in the Netherlands revealed that they discovered a spiral-shaped pattern in Chandra’s X-ray information. These results suggest a rough past for the cluster.
When 2 galaxy clusters of various sizes have a grazing crash, the smaller sized cluster will start to rake through the bigger one. (Because of its remarkable mass, the larger cluster has the upper hand when it concerns gravitational pull.) As the smaller sized cluster relocations through, its hot gas is removed off due to friction. This leaves a wake, or tail, that routes behind the cluster. After the center of the smaller sized cluster goes by the center of the bigger one, the gas in the tail begins to experience less resistance and overshoots the center of its cluster. This can trigger the tail to “slingshot” as it flies to the side, curving as it extends far from the cluster’s center.
The latest Chandra information includes proof — consisting of the brightness of the X-rays and the temperature levels they represent — for among these curving “slingshot” tails. Previous research studies of Abell 1775 with Chandra and other telescopes hinted, however did not verify, that there was a continuous crash in this system.
A brand-new picture of Abell 1775 includes X-rays from Chandra (blue), optical information from the Pan-STARRS telescope in Hawaii (blue, yellow, and white), and radio information from the LOw Frequency Variety (LOFAR) in the Netherlands (red). The tail is identified in this image together with an area of gas with a curved edge, called a “cold front,” that is denser and cooler than the gas it is raking into. The tail and the cold front all curve in the very same instructions, producing a spiral look. A different labeled image (listed below) reveals the field of vision of the Chandra information.
Labeled Multiwavelength Image of Abell 1775. Credit: X-ray: NASA/CXC/Leiden Univ./A. Botteon et al.; Radio: LOFAR/ASTRON; Optical/IR: PanSTARRS
Astronomers formerly discovered that Abell 1775 includes a massive jet and radio source, which is likewise seen in this brand-new composite image. This jet is powered by a supermassive great void in a big elliptical galaxy in the cluster’s center. New information from LOFAR and the Giant Metrewave Radio Telescope (GMRT) in India exposes that the radio jet is in fact 2.6 million light-years long. This has to do with two times as long as astronomers believed it was previously and makes it among the longest ever observed in a galaxy cluster. The structure of the jet modifications quickly as it crosses into the lower density gas in the upper part of the image, throughout the edge of the cold front, indicating that the crash has actually impacted it.
According to the brand-new research study, the gas movements inside the cluster might be accountable for other structures spotted by observing Abell 1775 in radio waves, such as 2 filaments situated near the origin of the jet (among these is identified). The LOFAR and Chandra information have actually likewise allowed the scientists to study in terrific information the phenomena that add to speeding up electrons both in this galaxy’s jet and in the radio emission near the center of the bigger cluster.
There is an alternate description for the look of the cluster. As a little cluster approaches a bigger one, the thick hot gas of the bigger cluster will be drawn in to it by gravity. After the smaller sized cluster passes the center of the other cluster, the instructions of movement of the cluster gas reverses, and it takes a trip back towards the cluster center. The cluster gas relocations through the center once again and “sloshes” backward and forward, comparable to red wine sloshing in a glass that was jerked sideways. The sloshing gas winds up in a spiral pattern since the crash in between the 2 clusters was off-center.
The Botteon group prefers the slingshot tail circumstance, however a different group of astronomers led by Dan Hu of Shanghai Jiao Tong University in China prefers the sloshing description based upon information from Chandra and ESA’s XMM-Newton. Both the slingshot and sloshing circumstances include an accident in between 2 galaxy clusters. Eventually, the 2 clusters will totally combine with each other to form a single, bigger galaxy cluster.
Further observations and modeling of Abell 1775 are needed to assist choose in between these 2 circumstances.
A paper explaining the outcomes by Botteon’s group has actually been released in the journal Astronomy and Astrophysics. The different deal with the “sloshing” theory led by Dan Hu has actually been accepted for publication in The Astrophysical Journal.
References:
“Nonthermal phenomena in the center of Abell 1775: An 800 kpc head-tail, restored fossil plasma and slingshot radio halo” by A. Botteon, S. Giacintucci, F. Gastaldello, T. Venturi, G. Brunetti, R. J. van Weeren, T. W. Shimwell, M. Rossetti, H. Akamatsu, M. Brüggen, R. Cassano, V. Cuciti, F. de Gasperin, A. Drabent, M. Hoeft, S. Mandal, H. J. A. Röttgering and C. Tasse, 11 May 2021, Astronomy and Astrophysics.
DOI: 10.1051/0004-6361/202040083
“The Merger Dynamics of the Galaxy Cluster A1775: New Insights from Chandra and XMM-Newton for a Cluster Simultaneously Hosting a Wide-angle Tail and a Narrow-angle Tail Radio Source” by Dan Hu, Haiguang Xu, Zhenghao Zhu, Chenxi Shan, Yongkai Zhu, Shida Fan, Yuanyuan Zhao, Chengze Liu, Hoongwah Siew, Zhongli Zhang, Liyi Gu, Melanie Johnston-Hollitt, Xi Kang, Qinghua Tan, Jiang Chang and Xiang-ping Wu, 18 May 2021, The Astrophysical Journal.
DOI: 10.3847/1538-4357/abf09e
NASA’s Marshall Space Flight Center handles the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center manages science from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.
