Skip to main content

Research Repository

Advanced Search

The effects of local stellar radiation and dust depletion on non-equilibrium interstellar chemistry

Richings, Alexander J.; Faucher-Giguère, Claude André; Gurvich, Alexander B.; Schaye, Joop; Hayward, Christopher C.

Authors

Profile Image

Dr Alex Richings A.J.Richings@hull.ac.uk
Lecturer in Data Science, Artificial Intelligence and Modelling

Claude André Faucher-Giguère

Alexander B. Gurvich

Joop Schaye

Christopher C. Hayward



Abstract

Interstellar chemistry is important for galaxy formation, as it determines the rate at which gas can cool, and enables us to make predictions for observable spectroscopic lines from ions and molecules. We explore two central aspects of modelling the chemistry of the interstellar medium (ISM): (1) the effects of local stellar radiation, which ionizes and heats the gas, and (2) the depletion of metals on to dust grains, which reduces the abundance of metals in the gas phase. We run high-resolution (400 M☉ per baryonic particle) simulations of isolated disc galaxies, from dwarfs to Milky Way-mass, using the FIRE galaxy formation models together with the CHIMES non-equilibrium chemistry and cooling module. In our fiducial model, we couple the chemistry to the stellar fluxes calculated from star particles using an approximate radiative transfer scheme; and we implement an empirical density-dependent prescription for metal depletion. For comparison, we also run simulations with a spatially uniform radiation field, and without metal depletion. Our fiducial model broadly reproduces observed trends in H I and H2 mass with stellar mass, and in line luminosity versus star formation rate for [C II]158μm, [O I]63μm, [O III]88μm, [N II]122μm, and H α6563Å. Our simulations with a uniform radiation field predict fainter luminosities, by up to an order of magnitude for [O III]88μm and H α6563Å, while ignoring metal depletion increases the luminosity of carbon and oxygen lines by a factor ≈ 2. However, the overall evolution of the galaxy is not strongly affected by local stellar fluxes or metal depletion, except in dwarf galaxies where the inclusion of local fluxes leads to weaker outflows and hence higher gas fractions.

Citation

Richings, A. J., Faucher-Giguère, C. A., Gurvich, A. B., Schaye, J., & Hayward, C. C. (2022). The effects of local stellar radiation and dust depletion on non-equilibrium interstellar chemistry. Monthly notices of the Royal Astronomical Society, 517(2), 1557-1583. https://doi.org/10.1093/mnras/stac2338

Journal Article Type Article
Acceptance Date Aug 16, 2022
Online Publication Date Aug 29, 2022
Publication Date 2022-12
Deposit Date Nov 23, 2022
Publicly Available Date Mar 28, 2024
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Oxford University Press
Peer Reviewed Peer Reviewed
Volume 517
Issue 2
Pages 1557-1583
DOI https://doi.org/10.1093/mnras/stac2338
Keywords Astrochemistry; ISM: atoms; ISM: molecules; Galaxies: evolution; Galaxies: ISM
Public URL https://hull-repository.worktribe.com/output/4131769

Files

Published article (4.1 Mb)
PDF

Publisher Licence URL
http://creativecommons.org/licenses/by/4.0

Copyright Statement
© 2022 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.




You might also like



Downloadable Citations