Facial reconstruction

Search LJMU Research Online

Browse Repository | Browse E-Theses

The imprint of dark subhaloes on the circumgalactic medium

McCarthy, IG and Font, AS (2020) The imprint of dark subhaloes on the circumgalactic medium. Monthly Notices of the Royal Astronomical Society, 499 (3). pp. 3255-3266. ISSN 0035-8711

The imprint of dark subhaloes on the circumgalactic medium.pdf - Published Version

Download (1MB) | Preview


The standard model of cosmology, the LCDM model, robustly predicts the existence of a multitude of dark matter 'subhaloes' around galaxies like the Milky Way. A wide variety of observations have been proposed to look for the gravitational effects such subhaloes would induce in observable matter. Most of these approaches pertain to the stellar or cool gaseous phases of matter. Here we propose a new approach, which is to search for the perturbations that such dark subhaloes would source in the warm/hot circumgalactic medium (CGM) around normal galaxies. With a combination of analytic theory, carefully-controlled high-resolution idealised simulations, and full cosmological hydrodynamical simulations, we calculate the expected signal and how it depends on important physical parameters (subhalo mass, CGM temperature, and relative velocity). We find that dark subhaloes enhance the local CGM pressure, density, and temperature, in order of decreasing magnitude of the effect. For the pressure, the fluctuations can vary in magnitude from tens of percent (for subhaloes with M_sub=10^10 Msun) to a few percent (for subhaloes with M_sub=10^8 Msun), although this depends strongly on the CGM temperature. The subhaloes also induce fluctuations in the velocity field ranging in magnitude from a few km/s up to 25 km/s. We propose that X-ray, Sunyaev-Zel'dovich effect, radio dispersion measure, and quasar absorption line observations can be used to measure these fluctuations and place constraints on the abundance and distribution of dark subhaloes, thereby placing constraints on the nature of dark matter.

Item Type: Article
Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2020 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords: astro-ph.CO; astro-ph.CO; astro-ph.GA
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Astrophysics Research Institute
Publisher: Oxford University Press
Related URLs:
Date Deposited: 09 Sep 2020 08:25
Last Modified: 04 Sep 2021 06:43
DOI or ID number: 10.1093/mnras/staa2767
URI: https://researchonline.ljmu.ac.uk/id/eprint/13602
View Item View Item