Tools
Tools
Meshveliani, T, Lovell, MR, Crain, RA and Pfeffer, J (2024) The impact of free-streaming on dwarf galaxy counts in low-density regions. Monthly Notices of the Royal Astronomical Society, 532 (2). pp. 1296-1306. ISSN 0035-8711
|
Text
The impact of free-streaming on dwarf galaxy counts in low-density regions.pdf - Published Version Available under License Creative Commons Attribution. Download (3MB) | Preview |
Abstract
We study the statistics of dwarf galaxy populations as a function of environment in cold dark matter (CDM) and warm dark matter (WDM; sterile neutrino model mass Ms = 7.1 keV; half-mode mass Mhm = 6.3 × 108 M☉; and thermal relic equivalent mass mth = 2.8 keV) cosmogonies, using the Evolution and Assembly of GaLaxies and their Environments (EAGLE) galaxy formation model in two counterpart simulations. We measure the abundance of dwarf galaxies within 3 Mpc of DM haloes with a present-day halo mass similar to the Milky Way, finding that the number of galaxies M∗ > 107 M☉ is nearly identical for WDM and CDM. However, the cumulative mass function becomes shallower for WDM at lower masses, yielding 50 per cent fewer dwarf galaxies of M∗ ≳ 105 M☉ than CDM. The suppression of low-mass halo counts in WDM increases significantly from high- to low-density regions for haloes in the [0.5, 2] × Mhm range. The fraction of haloes hosting resolvable galaxies (M∗ ≳ 105 M☉ ) also diverges from overdense to underdense regions for M > 2Mhm, as the increased collapse delay at small densities pushes the collapse to after the reionization threshold. However, the stellar mass of WDM haloes at [0.5, 2] × Mhm is 30 per cent higher per unit halo mass than CDM haloes in underdense regions. We conclude that the suppression of galaxies with M∗ ≳ 105 M☉ between WDM and CDM is independent of density: the suppression of halo counts and fraction of luminous haloes is balanced by an enhancement in stellar mass–halo mass relation.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | galaxies: abundances; galaxies: dwarf; galaxies: evolution; galaxies: formation; galaxies: groups: general; dark matter; 0201 Astronomical and Space Sciences; Astronomy & Astrophysics |
| Subjects: | Q Science > QB Astronomy Q Science > QC Physics |
| Divisions: | Astrophysics Research Institute |
| Publisher: | Oxford University Press (OUP) |
| SWORD Depositor: | A Symplectic |
| Date Deposited: | 08 Oct 2024 15:57 |
| Last Modified: | 08 Oct 2024 16:00 |
| DOI or ID number: | 10.1093/mnras/stae1519 |
| URI: | https://researchonline.ljmu.ac.uk/id/eprint/24459 |
 |
View Item |