A Caltech Library Service

Modelling chemical abundance distributions for dwarf galaxies in the Local Group: the impact of turbulent metal diffusion

Escala, Ivanna and Wetzel, Andrew and Kirby, Evan N. and Hopkins, Philip F. and Ma, Xiangcheng and Wheeler, Coral and Kereš, Dušan and Faucher-Giguère, Claude-André and Quataert, Eliot (2018) Modelling chemical abundance distributions for dwarf galaxies in the Local Group: the impact of turbulent metal diffusion. Monthly Notices of the Royal Astronomical Society, 474 (2). pp. 2194-2211. ISSN 0035-8711.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We investigate stellar metallicity distribution functions (MDFs), including Fe and α-element abundances, in dwarf galaxies from the Feedback in Realistic Environment (FIRE) project. We examine both isolated dwarf galaxies and those that are satellites of a Milky Way-mass galaxy. In particular, we study the effects of including a sub-grid turbulent model for the diffusion of metals in gas. Simulations that include diffusion have narrower MDFs and abundance ratio distributions, because diffusion drives individual gas and star particles towards the average metallicity. This effect provides significantly better agreement with observed abundance distributions in dwarf galaxies in the Local Group, including small intrinsic scatter in [α/Fe] versus [Fe/H] of ≲0.1 dex. This small intrinsic scatter arises in our simulations because the interstellar medium in dwarf galaxies is well mixed at nearly all cosmic times, such that stars that form at a given time have similar abundances to ≲0.1 dex. Thus, most of the scatter in abundances at z = 0 arises from redshift evolution and not from instantaneous scatter in the ISM. We find similar MDF widths and intrinsic scatter for satellite and isolated dwarf galaxies, which suggests that environmental effects play a minor role compared with internal chemical evolution in our simulations. Overall, with the inclusion of metal diffusion, our simulations reproduce abundance distribution widths of observed low-mass galaxies, enabling detailed studies of chemical evolution in galaxy formation.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Escala, Ivanna0000-0002-9933-9551
Wetzel, Andrew0000-0003-0603-8942
Kirby, Evan N.0000-0001-6196-5162
Hopkins, Philip F.0000-0003-3729-1684
Ma, Xiangcheng0000-0001-8091-2349
Kereš, Dušan0000-0002-1666-7067
Faucher-Giguère, Claude-André0000-0002-4900-6628
Quataert, Eliot0000-0001-9185-5044
Alternate Title:Modeling chemical abundance distributions for dwarf galaxies in the Local Group: the impact of turbulent metal diffusion
Additional Information:© 2017 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2017 November 1. Received 2017 October 31; in original form 2017 October 17. IE would like to thank the anonymous referee, in addition to Shea Garrison-Kimmel, Matthew Orr and Denise Schmitz, for helpful comments that improved this paper. Numerical calculations were run on the Caltech computing cluster ‘Zwicky’ (NSF MRI award #PHY-0960291) and allocation TG-AST130039 granted by the Extreme Science and Engineering Discovery Environment (XSEDE) supported by the NSF. IE was supported by Caltech funds, in part through the Caltech Earle C. Anthony Fellowship, and a Ford Foundation Predoctoral Fellowship. AW was supported by a Caltech-Carnegie Fellowship, in part through the Moore Center for Theoretical Cosmology and Physics at Caltech, and by NASA through grants HST-GO-14734 and HST-AR-15057 from STScI. ENK was supported by NSF Grant AST-1614081. Support for PFH was provided by an Alfred P. Sloan Research Fellowship, NASA ATP Grant NNX14AH35G, NSF Collaborative Research Grant #1411920 and CAREER grant #1455342. CW was supported by the Lee A. DuBridge Postdoctoral Scholarship in Astrophysics. DK was supported by NSF grant AST-1715101 and the Cottrell Scholar Award from the Research Corporation for Science Advancement. CAFG was supported by NSF through grants AST-1412836 and AST-1517491, by NASA through grant NNX15AB22G, and by STScI through grant HST-AR-14293.001-A. EQ was supported in part by a Simons Investigator Award from the Simons Foundation and NSF grant AST-1715070.
Group:TAPIR, Moore Center for Theoretical Cosmology and Physics, Astronomy Department
Funding AgencyGrant Number
Caltech Earle C. Anthony FellowshipUNSPECIFIED
Ford FoundationUNSPECIFIED
Caltech-Carnegie FellowshipUNSPECIFIED
Moore Center for Theoretical Cosmology and Physics, CaltechUNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Lee A. DuBridge FoundationUNSPECIFIED
Cottrell Scholar of Research CorporationUNSPECIFIED
Simons FoundationUNSPECIFIED
Subject Keywords:diffusion, methods: numerical, galaxies: abundances, galaxies: dwarf, Local Group
Issue or Number:2
Record Number:CaltechAUTHORS:20171031-190653134
Persistent URL:
Official Citation:Ivanna Escala, Andrew Wetzel, Evan N Kirby, Philip F Hopkins, Xiangcheng Ma, Coral Wheeler, Dušan Kereš, Claude-André Faucher-Giguère, Eliot Quataert; Modelling chemical abundance distributions for dwarf galaxies in the Local Group: the impact of turbulent metal diffusion, Monthly Notices of the Royal Astronomical Society, Volume 474, Issue 2, 21 February 2018, Pages 2194–2211,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:82826
Deposited By: Joy Painter
Deposited On:01 Nov 2017 12:57
Last Modified:22 Nov 2019 23:09

Repository Staff Only: item control page