# astro: runaway cooling of intracluster gas during a silent black hole

<< supermassive black holes play a fundamental role in regulating the formation of stars throughout cosmic time. This has been clearly demonstrated in the case of galaxy clusters in which powerful feedback from the central black hole is  preventing the hot intracluster gas from cooling catastrophically, thus reducing the expected star formation rates by orders of magnitude. >>

AA << present the first observational evidence for massive, runaway cooling occurring in the absence of supermassive black hole feedback in the high-redshift galaxy cluster SpARCS104922.6+564032.5 (..) The hot intracluster gas appears to be fueling a massive burst of star formation >>

<< Intracluster stars are therefore not only produced by tidal stripping and the disruption of cluster galaxies, but can also be produced by runaway cooling of hot intracluster gas at early times. Overall, these observations show the dramatic impact when supermassive black hole feedback fails to operate in clusters. They indicate that in the highest overdensities such as clusters and proto-clusters, runaway cooling may be a new and important mechanism for fueling massive bursts of star formation in the early universe. >>

J. Hlavacek-Larrondo, C.L. Rhea, et al. Evidence of runaway gas cooling in the absence of supermassive black hole feedback at the epoch of cluster formation. arXiv:2007.15660v1 [astro-ph.GA]. Jul 30, 2020.

https://arxiv.org/abs/2007.15660   

<< It reminds me of the old expression of 'when the cat's away, the mice will play,' (..) Here the cat, or black hole, is quiet and the mice, or stars, are very busy. >> Julie Hlavacek

Black hole fails to do its job. Chandra X-ray Center. Aug 3, 2020. 

https://phys.org/news/2020-08-black-hole-job.html