AR 17037 (Archival Research)

Thu Jul 18 15:06:48 GMT 2024

Principal Investigator: Ming Sun
PI Institution: University of Alabama in Huntsville
Investigators (xml)

Title: Constraining star formation with the deepest HST images of M87
Cycle: 30

While AGN feedback has emerged as a key ingredient in galaxy formation and suppressing cooling in X-ray cool cores, heating cannot stop cooling at all times and all spatial scales. Indeed, star formation (SF) is still common in X-ray cool cores around the brightest central galaxies (BCGs). SF in BCGs is the final sink term in the energy balance/transfer in the the multi-phase medium. The relation between radio AGN and SF is an important question in AGN feedback. For strong X-ray cool cores associated with strong radio AGN, besides the studies on ones with strong SF, detailed studies on ones with weak SF is also required for a complete understanding of the feedback cycle. We argue that the closest BCG M87 is the best object for such kind of studies and propose an HST archival study of M87 with the deepest HST data available to any BCG, especially taking advantage of the recently available deep WFC3/UV data. SF indeed happens in M87 but at a low level. These deep HST data, combined with the proximity of M87, present a rare opportunity to study low-level SF in X-ray cool cores, which is impossible in more distant cool cores. Some initial analysis has been finished to reveal a population of UV-bright sources resembling young star clusters. Young star clusters will be identified. Their connection with optical emission-line filaments, soft X-ray clumps, recent AGN shocks and outbursts will be probed. We will constrain the recent star formation history in M87 and link it to the recent history of cooling and AGN outbursts in M87 revealed from the radio and X-ray data. The results will also have general implications for the radio AGN feedback cycles in X-ray cool cores.