OMEGA - OSIRIS mapping of emission-line galaxies in A901/2: III. - Galaxy properties across projected phase space in A901/2

Weinzirl, Tim; Arag�n-Salamanca, Alfonso; Gray, Meghan E.; Bamford, Steven P.; Rodriguez Del Pino, Bruno; Chies-Santos, Ana L.; B�hm, Asmus; Wolf, Christian; Cool, Richard J.

Abstract

We conduct a comprehensive projected phase-space analysis of the A901/2 multicluster system at z ∼ 0.165. Aggregating redshifts from spectroscopy, tunable-filter imaging and prism techniques, we assemble a sample of 856 cluster galaxies reaching 108.5 M⊙ in stellar mass. We look for variations in cluster galaxy properties between virialized and non-virialized regions of projected phase space (PPS). Our main conclusions point to relatively gentle environmental effects, expressed mainly on galaxy gas reservoirs. (1) Stacking the four subclusters in A901/2, we find galaxies in the virialized region are more massive, redder and have marginally higher Sérsic indices, but their half-light radii and Hubble types are not significantly different. (2) After accounting for trends in stellar mass, there is a remaining change in rest-frame colour across PPS. Primarily, the colour difference is due to the absence in the virialized region of galaxies with rest frame B − V < 0.7 and moderate-to-high (M⋆ > 109.85 M⊙) stellar mass. (3) There is an infalling population of lower mass (M⋆ ≤ 109.85 M⊙), relatively blue (B − V < 0.7) elliptical or spheroidal galaxies that are strikingly absent in the virialized region. (4) The number of bona fide star-forming and active galactic nucleus galaxies in the PPS regions is strongly dictated by stellar mass. However, there remains a reduced fraction of star-forming galaxies in the centres of the clusters at fixed stellar mass, consistent with the star formation–density relation in galaxy clusters. (5) There is no change in specific Hα-derived star formation rates of star-forming galaxies at fixed mass across the cluster environment. This suggests that pre-processing of galaxies during infall plays a prominent role in quenching star formation.

Citation

Weinzirl, T., Aragón-Salamanca, A., Gray, M. E., Bamford, S. P., Rodriguez Del Pino, B., Chies-Santos, A. L., …Cool, R. J. (2017). OMEGA - OSIRIS mapping of emission-line galaxies in A901/2: III. - Galaxy properties across projected phase space in A901/2. Monthly Notices of the Royal Astronomical Society, 471(1), 182-200. https://doi.org/10.1093/mnras/stx1525

• Journal Article Type: Article
• Acceptance Date: Jun 15, 2017
• Online Publication Date: Jun 17, 2017
• Publication Date: Oct 31, 2017
• Deposit Date: Jun 21, 2017
• Publicly Available Date: Jun 21, 2017
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 471
• Issue: 1
• Pages: 182-200
• DOI: https://doi.org/10.1093/mnras/stx1525
• Keywords: instrumentation: interferometers, galaxies: clusters: individual: A901/2, galaxies: distances and redshifts, galaxies: star formation
• Public URL: https://nottingham-repository.worktribe.com/output/890767
• Publisher URL: https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stx1525
• Related Public URLs: https://arxiv.org/abs/1706.05199
• Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2017 The authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.