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environments of the radio galaxy population in simba.

Authors :
Thomas, Nicole
Davé, Romeel
Source :
Monthly Notices of the Royal Astronomical Society. Oct2022, Vol. 515 Issue 4, p5539-5555. 17p.
Publication Year :
2022

Abstract

We investigate the environmental properties of the z  = 0 radio galaxy population using the simba cosmological hydrodynamic simulation. We identify centrals and satellites from a population of high and low excitation radio galaxies (HERGs and LERGs) in simba , and study their global properties. We find that |$\sim 20{{\ \rm per\ cent}}$| of radio galaxies are satellites, and that there are insignificant differences in the global properties of LERGs based on their central/satellite classification. HERG satellites display lower values of star formation, 1.4 GHz radio luminosity, and Eddington fractions than HERG centrals. We further investigate the environments of radio galaxies and show that HERGs typically live in less dense environments, similar to star-forming galaxies. The environments of high-mass LERGs are similar to non-radio galaxies, but low-mass LERGs live in underdense environments similar to HERGs. LERGs with overmassive black holes reside in the most dense environments, while HERGs with overmassive black holes reside in underdense environments. The richness of a LERG's environment decreases with increasing Eddington fraction, and the environments of all radio galaxies do not depend on radio luminosity for |$\, P_{\rm 1.4~GHz}\lt 10^{24} \rm {~W~Hz}^{-1}$|⁠. Complementing these results, we find that LERGs cluster on the same scale as the total galaxy population, while multiple HERGs are not found within the same dark matter halo. Finally, we show that high density environments support the growth of HERGs rather than LERGs at z  = 2. Simba predicts that with more sensitive surveys, we will find populations of radio galaxies in environments much similar to the total galaxy population. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00358711
Volume :
515
Issue :
4
Database :
Academic Search Index
Journal :
Monthly Notices of the Royal Astronomical Society
Publication Type :
Academic Journal
Accession number :
158941906
Full Text :
https://doi.org/10.1093/mnras/stac2175