Abstract
The enormous sizes and masses of Brightest Cluster Galaxies (BCGs) always posed a peculiar challenge to our understanding of galaxy growth evolution. The understanding of BCG growth begins with the ancestral massive quiescent galaxies at redshift of 2 (about 10 billion years ago), having half the mass of local BCGs and sizes nearly 1/5 of those of the current ones. The conventional view of subsequent growth has been described by the successive minor mergers with gas poor cluster member galaxies. Nonetheless, the low estimated minor merger rates at higher redshifts, along with the observed excess UV continuum seemly raise questions on this model, leaving star formation as a possible additional growth mechanism for BCGs. In this talk, I will be discussing the role of star formation in growth of BCGs, primarily through the case study of NGC 1275. This is a BCG in the Perseus cluster hosting luminous emission line nebula, and prominent star formation activity primarily in forms of sustained formation of blue star clusters (BSCs). From our work, we will show the importance of such tidally disrupted BSCs in contributing to the growth of NCG 1275. I will then further delve into the study of evolutionary growth and current state of galaxy clusters in Cluster Lensing And Supernova survey with Hubble (CLASH) sample, investigating their possible imprints on the intra-cluster medium’s thermodynamical properties and their relations with BCG star formation activity.
Anyone interested is welcome to attend.