Language
Country/Area
No result found
The surprising discovery of the Phoenix cluster: How was this cosmic beast observed for the first time?
In the deep universe revealed for the first time by satellite images, the Phoenix Cluster (SPT-CL J2344-4243) is like a pearl among the stars, attracting the attention of astronomers. This group of galaxies, located in the southern constellation Phoenix, is one of the brightest astronomical objects in the universe today due to its large size and unique features. Since it was first observed by the South Pole Telescope in 2010, the Phoenix Cluster has been one of the most massive and brightest X-ray galaxy groups known.
The mass of the Phoenix cluster is about 2×1015 M☉ and it is about 8.61 billion light-years away from Earth.
Discovery process
The first report of the Phoenix cluster was by R. Williamson and colleagues in a survey of 2500 square degrees of the southern sky using the South Pole Telescope. According to the report, the Phoenix Cluster is one of 26 identified galaxy groups and is noted for its outstanding X-ray brightness.
This group is described in the survey as having the "greatest X-ray brightness".
In the center of the cluster, a bright type 2 Seyfert galaxy named Phoenix A attracted the researchers' attention. This galaxy is only 19 arc seconds from the center of the cluster and is key to understanding the Phoenix Cluster.
Characteristics and Behavior
Due to its extreme physical properties, the Phoenix Cluster has become a focus of study. Multi-band observations by M. McDonald and his team showed that its cooling flow rate is as high as about 3,280 M☉ per year, making it one of the strongest cooling flows in the galaxy group. This phenomenon is different from other galaxy groupings because in the Phoenix Cluster the cooling mechanism has not yet been fully established.
The active galactic nucleus at its center fails to generate enough energy to ionize the gas within the galaxy.
Phoenix A is forming an astonishing number of stars, with a star formation rate of 740 M☉ per year, which is much higher than the Milky Way, which only forms 1 M☉ per year, making it particularly outstanding among the central galaxies of galaxy groups.
Composition
Central Galaxy
The central star system of the Phoenix Cluster is Phoenix A, which has a supermassive black hole driving its active galactic nucleus. Due to its unique morphology, Phoenix A has an angular diameter of 16.20 arc seconds and possesses more biomass than all other galaxies in the group combined.
The cooling rate of its central region is as high as 3,820 M☉ per year, the highest value ever recorded.
Supermassive black hole
At the heart of it all is the Phoenix cluster's central black hole, driving Phoenix A's galactic activity. By modeling the density of stars and their heat flow inside the galaxy, scientists speculate that the mass of the black hole may be as high as 100 billion M☉, and this high-quality black hole may even have the potential to become one of the most massive black holes known in the universe. .
This mass puts it at around 24,100 times the mass of the black hole at the centre of our Milky Way galaxy, and could raise deeper cosmological questions.
Such a high mass puts it into the category of possible "supermassive black holes" and suggests something peculiar about its early formation. The discovery of the Phoenix Cluster not only helped scientists better understand the evolution of galaxies, but also triggered a series of heated discussions on black holes and their causes.
Will the process of discovering these astonishing truths change our understanding of the universe, and what secrets are hidden behind the galaxies?