Post date: Aug 28, 2017 1:11:54 AM
Monday's meeting, at 11am.
Location: Auditorio Novo 1 in the Instituto de Fisica of USP. Please notice the unusual room in USP.
Antonio Montero Dorta is going to tell us about his recent work on the observational evidence of galaxy assembly bias (see below for title and abstract).
We will also have time for the paper discussion, so, please upload your favourite papers to discuss on our CosmoCoffee page
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"THE DEPENDENCE OF GALAXY CLUSTERING ON STELLAR-MASS ASSEMBLY HISTORY FOR LRGS"
(Observational evidence of galaxy assembly bias?)
We analyze the spectra of 300,000 luminous red galaxies (LRGs) with stellar masses M_* > 10^11 solar masses from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS).
By studying their star-formation histories, we find two main evolutionary paths converging into the same quiescent galaxy population at z~0.55. Fast-growing LRGs assemble 80% of their stellar mass very early on (z~5), whereas slow-growing LRGs reach the same evolutionary
state at z~1.5. Further investigation reveals that their clustering properties on scales of ~1--30 Mpc are, at a high level of significance, also different. Fast-growing LRGs are found to be more strongly clustered and reside in overall denser large-scale structure environments than slow-growing systems, for a given stellar-mass threshold.
Our results show a dependence of clustering on a property that is directly related to the evolution of galaxies, i.e. the stellar-mass assembly history, for a homogeneous population of similar stellar mass and color. I will discuss the implications of our observational results in the
context of galaxy assembly bias.