Riggs, Stephen D, Loveday, Jon, Thomas, Peter A, Pillepich, Annalisa, Nelson, Dylan and Holwerda, Benne W (2022) Exploring the effect of baryons on the radial distribution of satellite galaxies with GAMA and IllustrisTNG. Monthly Notices of the Royal Astronomical Society, 514 (4). pp. 4676-4695. ISSN 0035-8711

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Abstract

We explore the radial distribution of satellite galaxies in groups in the Galaxy and Mass Assembly (GAMA) survey and the IllustrisTNG simulations. Considering groups with masses 12.0 ≤ log10(M/−1M) < 14.8 at < 0.267, we find a good agreement between GAMA and a sample of TNG300 groups and galaxies designed to match the GAMA selection. Both display a flat profile in the centre of groups, followed by a decline that becomes steeper towards the group edge, and normalised profiles show no dependence on group mass. Using matched satellites from TNG and dark matter-only TNG-Dark runs we investigate the effect of baryons on satellite radial location. At = 0, we find that the matched subhaloes from the TNG-Dark runs display a much flatter radial profile: namely, satellites selected above a minimum stellar mass exhibit both smaller halo-centric distances and longer survival times in the full-physics simulations compared to their dark-matter only analogues. We then divide the TNG satellites into those which possess TNG-Dark counterparts and those which do not, and develop models for the radial positions of each. Wefindthesatellites with TNG-Dark counterparts are displaced towards the halo centre in the full-physics simulations, and this difference has a power-law behaviour with radius. For the ‘orphan’ galaxies without TNG-Dark counterparts, we consider the shape of their radial distribution and provide a model for their motion over time, which can be used to improve the treatment of satellite galaxies in semi-analytic and semi-empirical models of galaxy formation.

Item Type:	Article
Schools and Departments:	School of Mathematical and Physical Sciences > Mathematics School of Mathematical and Physical Sciences > Physics and Astronomy
SWORD Depositor:	Mx Elements Account
Depositing User:	Mx Elements Account
Date Deposited:	23 Jun 2022 17:48
Last Modified:	22 Jul 2022 07:03
URI:	http://sro.sussex.ac.uk/id/eprint/106585

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