Title:	Passive spirals and shock influenced star formation in the merging cluster A3376
Authors:	Kelkar, Kshitija Dwarakanath, K.S. Poggianti, Bianca M. +8 Co-Authors
Keywords:	galaxies:clusters:general galaxies:disc galaxies:evolution
Issue Date:	Jul-2020
Publisher:	Oxford University Press on behalf of the Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2020, Vol.496, p442–455
Abstract:	We present a detailed analysis of star formation properties of galaxies in a nearby (z ∼ 0.046) young (∼0.6 Gyr) post-merger cluster system A3376, with a moderate merger shock front (vs ∼1630 km s-1; M ∼ 2) observed as symmetric radio relics. Exploiting the spectroscopic data from the wide-field OmegaWINGS survey and the associated photometric information, our investigations reveal the plausible effects of the dynamic post-merger environment differing from the high-density cluster environment experienced prior to the merging activity. The remnants of the pre-merger relaxed cluster environment are realized through the existence of passive spiral galaxies located in the central regions of the cluster between the two brightest cluster galaxies. We discover A3376 to contain a population of massive (log (M*/M☉) > 10) blue regular star-forming spirals in regions of maximum merger shock influence but exhibiting star formation rates similar to those in relaxed clusters at similar epoch. We further discover low-mass (log (M*/M☉) ≤ 10) late-type blue post-starburst galaxies which could either be formed as a result of rapid quenching of low-mass spirals following the shock-induced star formation or due to the intense surge in the intracluster medium pressures at the beginning of the merger. With the possibility of the merger shock affecting high- and low-mass spirals differently, our results bridge the seemingly contradictory results observed in known merging cluster systems so far and establish that different environmental effects are at play right from pre- to post-merger stages.
Description:	Open Access
URI:	http://hdl.handle.net/2289/7501
ISSN:	0035-8711 1365-2966 (online)
Alternative Location:	https://ui.adsabs.harvard.edu/abs/2020MNRAS.496..442K/abstract https://doi.org/10.1093/mnras/staa1547
Copyright:	2020 The Author(s)
Appears in Collections:	Research Papers (A&A)

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