Evidence for galaxies being pre-processed before accreted into clusters

Mahajan, Smriti (2013) Evidence for galaxies being pre-processed before accreted into clusters. Monthly Notices of the Royal Astronomical Society. Letters, 431 1: L117-L121. doi:10.1093/mnrasl/slt021

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Author Mahajan, Smriti
Title Evidence for galaxies being pre-processed before accreted into clusters
Journal name Monthly Notices of the Royal Astronomical Society. Letters   Check publisher's open access policy
ISSN 1745-3925
Publication date 2013-05
Year available 2013
Sub-type Article (original research)
DOI 10.1093/mnrasl/slt021
Open Access Status File (Publisher version)
Volume 431
Issue 1
Start page L117
End page L121
Total pages 5
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Collection year 2014
Language eng
Formatted abstract
I use the spectroscopic data for galaxies in and around 28 nearby (0.02 ≤ z ≤ 0.06) X-ray bright galaxy clusters, to show that the incidence of k+A (or post-starburst) galaxies (EW(Ha) < 2Å in emission and EW(Hd) > 3Å in absorption) may be correlated with the accretion of small galaxy groups in clusters. At r < 2r200, the k+A galaxies are found in regions of higher galaxy density relative to other cluster galaxies. The k+A galaxies have a positively skewed distribution of absolute velocity, vlos/σv, where vlos is the difference between the line-of-sight velocity of the galaxy and the cluster's mean, and σv is the cluster's velocity dispersion. This distribution is statistically different from that of other cluster galaxies within 2r200, and in the same absolute velocity range. Moreover, 87 per cent of clusters in the sample studied here show statistically significant substructure in their velocity distribution, and 91.4 per cent of all the k+A galaxies are found to be a part of one of these substructures with 4-10 members. These results suggest that star formation in these k+A galaxies is likely to have been quenched due to 'pre-processing' in a poor group-like environment before they are accreted into clusters. I also find a mild, but statistically significant trend in the fraction of k+A galaxies increasing with the temperature of the X-ray emitting gas in clusters.
Keyword Galaxies
Clusters Of Galaxies
Galaxies evolution
X-rays general
Star Formation
Post Starburst Galaxies
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
Official 2014 Collection
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Citation counts: TR Web of Science Citation Count  Cited 6 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 5 times in Scopus Article | Citations
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