Satellite quenching, Galaxy inner density and the halo environment

Joanna Woo*, C. M. Carollo, S. M. Faber, Avishai Dekel, Sandro Tacchella

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

36 Scopus citations

Abstract

Using the Sloan Digital Sky Survey, we adopt the specific star formation rate (sSFR)-∑*,1kpc diagram as a diagnostic tool to understand quenching in different environments. sSFR is the specific star formation rate and ∑*,1kpc is the stellar surface density in the inner kpc. Although both the host halo mass and group-centric distance affect the satellite population, we find that these can be characterized by a single number, the quenched fraction, such that key features of the sSFR-∑*,1kpc diagram vary smoothly with this proxy for the 'environment'. Particularly, the sSFR of star-forming galaxies decreases smoothly with this quenched fraction, the sSFR of satellites being 0.1 dex lower than in the field. Furthermore, ∑*,1kpc of the transition galaxies (i.e. the 'green valley' or GV) decreases smoothly with the environment by as much as 0.2 dex for M* = 109.75-10 from the field, and decreasing for satellites in larger haloes and at smaller radial distances within same-mass haloes. We interpret this shift as indicating the relative importance of today's field quenching track versus the cluster quenching track. These environmental effects in the sSFR-∑*,1kpc diagram are most significant in our lowest mass range (9.75 < logM*/M < 10). One feature that is shared between all environments is that at a given M*, quenched galaxies have about 0.2-0.3 dex higher ∑*,1kpc than the starforming population. These results indicate that either ∑*,1kpc increases (subsequent to satellite quenching), or ∑*,1kpc for individual galaxies remains unchanged, but the original M* or the time of quenching is significantly different from those now in the GV.

Original languageEnglish
Pages (from-to)1077-1094
Number of pages18
JournalMonthly Notices of the Royal Astronomical Society
Volume464
Issue number1
DOIs
StatePublished - 1 Jan 2017

Bibliographical note

Publisher Copyright:
© 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Keywords

  • Galaxies: clusters: general
  • Galaxies: evolution
  • Galaxies: groups: general
  • Galaxies: haloes
  • Galaxies: structure

Fingerprint

Dive into the research topics of 'Satellite quenching, Galaxy inner density and the halo environment'. Together they form a unique fingerprint.

Cite this