When a Black Hole Fails to do its Job

• Main Author: Rhea, Carter
• Format: Conference Object
• Language: unknown
• Published: Zenodo 2021
• Subjects: Galaxy Cluster; South Pole; South pole
• Online Access: https://dx.doi.org/10.5281/zenodo.4985648; https://zenodo.org/record/4985648

The study of Stellar Formation Rates has long been at the heart of galactic/extragalactic astrophysics. Recent galaxy cluster surveys, such as the South Pole Telescope Survey, have revealed that high redshift (z>1) galaxy clusters, unlike their local counterparts, are regions of intense star formation. Previous studies suggest the buildup of stellar mass through positive feedback mechanisms such as major mergers and ram pressure stripping; however our recent investigation of the massive galaxy cluster SpARCS104922.6+564032.5 reveals a new and unexpected mechanism -- an unrestrained cooling flow. More precisely, the cluster stands out as harboring a still assembling brightest cluster galaxy (BCG) undergoing extreme stellar formation at z=1.7091 (~850 M☉/yr). Here, we present 170 ks (~50 hours) of new Chandra observations. Using several techniques for calculating galactic substructure and proxies of cooling flows, we develop a more coherent image of the mechanism responsible for the rampant stellar formation of the BCG. Our results show the presence of a strong cooling flow cospatial with the region of intense star formation ~50 kpc from the BCG indicating a lack of AGN feedback in the system -- in direct contrast to local counterparts. Moreover, the lack of a mechanism to suppress star formation appears to be providing the ideal environment for a buildup of intracluster light. This demonstrates a novel mechanism for the formation of stellar mass in galaxy clusters.