Galaxy and Mass Assembly (GAMA): Environmental quenching of centrals and satellites in groups

Authors

L. J.M. Davies, The University of Western Australia
A. S.G. Robotham, The University of Western Australia
C. Del P. Lagos, The University of Western Australia
S. P. Driver, The University of Western Australia
A. R.H. Stevens, The University of Western Australia
Y. M. Bahé, Leiden Observatory Research Institute
M. Alpaslan, The Center for Cosmology and Particle Physics
M. N. Bremer, University of Bristol
M. J.I. Brown, Monash University
S. Brough, UNSW Sydney
J. Bland-Hawthorn, The University of Sydney
L. Cortese, The University of Western Australia
P. Elahi, The University of Western Australia
M. W. Grootes, Netherlands eScience Center
Benne W. Holwerda, University of LouisvilleFollow
A. D. Ludlow, The University of Western Australia
S. McGee, University of Birmingham
M. Owers, Macquarie University
S. Phillipps, University of Bristol

Document Type

Article

Publication Date

3-11-2019

Department

Physics and Astronomy

Abstract

Recently a number of studies have found a similarity between the passive fraction of central and satellite galaxies when controlled for both stellar and halo mass. These results suggest that the quenching processes that affect galaxies are largely agnostic to central/satellite status, which contradicts the traditional picture of increased satellite quenching via environmental processes such as stripping, strangulation, and starvation. Here we explore this further using the Galaxy And Mass Assembly (GAMA) survey, which extends to ~2 dex lower in stellar mass than SDSS, is more complete for closely separated galaxies (≳395 per cent compared to ≳370 per cent), and identifies lower-halo-mass groups outside of the very local Universe (M halo ~ 10 12 M ⊙ at 0.1 < z < 0.2). As far as possible we aim to replicate the selections, completeness corrections, and central/satellite division of one of the previous studies but find clear differences between passive fractions of centrals and satellites. We also find that our passive fractions increase with both halo-to-satellite mass ratio and central-to-second rank mass ratio. This suggests that quenching is more efficient in satellites that are low-mass for their halo (i.e. at high halo-to-satellite mass ratio in comparison to low halo-to-satellite mass ratio) and are more likely to be passive in older groups - forming a consistent picture of environmental quenching of satellites. We then discuss potential explanations for the previously observed similarity, such as dependence on the group-finding method.

ThinkIR Citation

Davies, L. J.M.; Robotham, A. S.G.; Lagos, C. Del P.; Driver, S. P.; Stevens, A. R.H.; Bahé, Y. M.; Alpaslan, M.; Bremer, M. N.; Brown, M. J.I.; Brough, S.; Bland-Hawthorn, J.; Cortese, L.; Elahi, P.; Grootes, M. W.; Holwerda, Benne W.; Ludlow, A. D.; McGee, S.; Owers, M.; and Phillipps, S., "Galaxy and Mass Assembly (GAMA): Environmental quenching of centrals and satellites in groups" (2019). Faculty Scholarship. 487.
https://ir.library.louisville.edu/faculty/487

DOI

10.1093/mnras/sty3393

ORCID

0000-0002-4884-6756