Taranu, Dan S. and Hudson, Michael J. and Balogh, Michael L. and Smith, Russell J. and Power, Chris and Oman, Kyle A. and Krane, Brad (2014) 'Quenching star formation in cluster galaxies.', Monthly notices of the Royal Astronomical Society., 440 (3). pp. 1934-1949.
In order to understand the processes that quench star formation in cluster galaxies, we construct a library of subhalo orbits drawn from Λ cold dark matter cosmological N-body simulations of four rich clusters. We combine these orbits with models of star formation followed by environmental quenching, comparing model predictions with observed bulge and disc colours and stellar absorption line-strength indices of luminous cluster galaxies. Models in which the bulge stellar populations depend only on the galaxy subhalo mass while the disc is quenched upon infall are acceptable fits to the data. An exponential disc quenching time-scale of 3–3.5 Gyr is preferred. Quenching in lower mass groups prior to infall (‘pre-processing’) provides better fits, with similar quenching time-scales. Models with short (≲1 Gyr) quenching time-scales yield excessively steep cluster-centric gradients in disc colours and Balmer line indices, even if quenching is delayed for several Gyr. The data slightly prefer models where quenching occurs only for galaxies falling within ∼0.5r200. These results imply that the environments of rich clusters must impact star formation rates of infalling galaxies on relatively long time-scales, indicative of gentler quenching mechanisms such as slow ‘strangulation’ over more rapid ram-pressure stripping.
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|Publisher Web site:||https://doi.org/10.1093/mnras/stu389|
|Publisher statement:||This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2014 Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.|
|Date accepted:||26 February 2014|
|Date deposited:||23 August 2018|
|Date of first online publication:||03 April 2014|
|Date first made open access:||No date available|
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