2017/01/31 by Kevin Fogarty, Marc Postman, Rebecca Larson +2 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Cluster (spacecraft) #Cooling flow #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Intracluster medium #RADIUS #Scaling #Star formation #Stellar mass #astro-ph.GA
paper · pdf · doi:10.3847/1538-4357/aa82b9
Accepted for publication in the Astrophysical Journal; 31 pages, 16 figures. Revised X-ray data analysis; minor revisions to reporting of dust masses and burst durations. Discussion section revised. Text edited for clarity
openalex created_date 2017/02/03 · arxiv created 2017/07/20 · openalex publication_date 2017/09/06 · arxiv updated 2017/09/13 · openalex updated_date 2026/08/05
Abstract We study the nature of feedback mechanisms in the 11 CLASH brightest cluster galaxies (BCGs) that exhibit extended ultraviolet and nebular line emission features. We estimate star formation rates (SFRs), dust masses, and starburst durations using a Bayesian photometry-fitting technique that accounts for both stellar and dust emission from the UV through far-IR. By comparing these quantities to intracluster medium (ICM) cooling times and freefall times derived from X-ray observations and lensing estimates of the cluster mass distribution, we discover a tight relationship between the BCG SFR and the ICM cooling time to freefall time ratio, , with an upper limit on the intrinsic scatter of 0.15 dex. Furthermore, starburst durations may correlate with ICM cooling times at a radius of , and the two quantities converge upon reaching the gigayear regime. Our results provide a direct observational link between the thermodynamical state of the ICM and the intensity and duration of BCG star formation activity, and appear consistent with a scenario where active galactic nuclei induce condensation of thermally unstable ICM overdensities that fuel long-duration (>1 Gyr) BCG starbursts. This scenario can explain (a) how gas with a low cooling time is depleted without causing a cooling flow and (b) the scaling relationship between SFR and . We also find that the scaling relation between SFR and dust mass in BCGs with SFRs yr −1 is similar to that in star-forming field galaxies; BCGs with large ( yr −1 ) SFRs have dust masses comparable to extreme starbursts.