Artist’s depiction of works seen in observations. Credit: NAOJ
Radio astronomers a. Has found a jet of hot gas emitted by Black hole In the galaxy in the center of the Phoenix galaxy cluster, located 9.9 billion light-years away in the constellation Phoenix. This is an important consequence for understanding the covolution of galaxies, gases and black holes in galaxy clusters.
Galaxies do not distribute randomly in space. By mutual gravitational attraction, galaxies come together to form a collection called clusters. The space between the galaxies is not completely empty. A cluster contains a very thin gas that can be detected by X-ray observations.
If this intra-cluster gas cools, it will condense under its own gravity, forming stars in the center of the cluster. However, cooled gases and stars are not usually found in the heart of nearby clusters, indicating that some method is heating up intra-cluster gases and preventing star formation. One potential candidate for the heat source is a jet of high-speed gas accelerated by a super-giant black hole in the central galaxy.
The phoenix cluster is unusual in that it shows signs of cooling gas and massive star formation around the central galaxy. The question is, “Is there a black hole jet in the central galaxy?”
Radio observations of the center of the Phoenix galaxy cluster, showing jet formations extending from the central structure. Credit: Akahori et al.
A team led by Takaya Akahori at Japan’s National Astronomical Observatory has used the Australia Telescope Compact Array (ATCA) to search for a black hole jet in the Phoenix Galaxy cluster, the highest resolution to date. They found matching formations extending from opposite sides of the central galaxy. Comparison of region observations taken from lunar X-ray observatory archive data shows that the formations detected by the ATCA correspond to low-density gas cavities, indicating that they are a pair of bipolar planes mitted out of the galaxy’s black hole. Therefore, the team found the first example in which intra-cluster gas cooling and black hole jets coexist in the interstellar universe.
Further details of galaxies and jets can be clarified by high-resolution observations with next-generation observation features such as the Square Kilometer Array, scheduled to begin in the late 2020s.
These results t. Appeared as Akahori et al. “Radio Jet Discovered at Phoenix Galaxy Cluster Center” Japan August 2020 Publications of the Astronomical Society of Japan in August 2020.
References: Takuya Akahori, Tetsu Kitayama, Shutaro Uda, Takuma Izumi, Qianhong Lee, Ryohi Kawabe, Kotoro Kohno, Masamune Oguri and Motokazu Takizawa, 27 May 2020, “Discovery of Radio Jet at Phoenix Galaxy Cluster Center” Publications of the Astronomical Society of Japan.
DOI: 10.1093 / pasj / psaa039
