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Variations in the slope of the resolved star-forming main sequence: a tool for constraining the mass of star-forming regions

Hani, Maan H. and Hayward, Christopher C. and Orr, Matthew E. and Ellison, Sara L. and Torrey, Paul and Murray, Norm and Wetzel, Andrew and Faucher-Giguère, Claude-André (2020) Variations in the slope of the resolved star-forming main sequence: a tool for constraining the mass of star-forming regions. Monthly Notices of the Royal Astronomical Society: Letters, 493 (1). L87-L91. ISSN 1745-3925.

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The correlation between galaxies’ integrated stellar masses and star formation rates (the ‘star formation main sequence’, SFMS) is a well-established scaling relation. Recently, surveys have found a relationship between the star formation rate (SFR) and stellar mass surface densities on kpc and sub-kpc scales (the ‘resolved SFMS’, rSFMS). In this work, we demonstrate that the rSFMS emerges naturally in Feedback In Realistic Environments 2 (FIRE-2) zoom-in simulations of Milky Way-mass galaxies. We make SFR and stellar mass maps of the simulated galaxies at a variety of spatial resolutions and star formation averaging time-scales and fit the rSFMS using multiple methods from the literature. While the absolute value of the SFMS slope (α_(MS)) depends on the fitting method, the slope is steeper for longer star formation time-scales and lower spatial resolutions regardless of the fitting method employed. We present a toy model that quantitatively captures the dependence of the simulated galaxies’ α_(MS) on spatial resolution and use it to illustrate how this dependence can be used to constrain the characteristic mass of star-forming clumps.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Hani, Maan H.0000-0002-5351-2291
Hayward, Christopher C.0000-0003-4073-3236
Orr, Matthew E.0000-0003-1053-3081
Ellison, Sara L.0000-0002-1768-1899
Torrey, Paul0000-0002-5653-0786
Wetzel, Andrew0000-0003-0603-8942
Faucher-Giguère, Claude-André0000-0002-4900-6628
Additional Information:© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Accepted 2020 January 20. Received 2020 January 17; in original form 2019 September 11. Published: 23 January 2020. The authors thank the anonymous referee for their helpful comments that improved the presentation of this work. The authors thank Connor Bottrell, Greg Bryan, John Forbes, Shy Genel, Li-Hwai Lin, Nic Loewen, Ari Maller, Hsi-An Pan, David Patton, Rachel Somerville, Mallory Thorp, and Joanna Woo for their insightful comments and helpful discussions. MHH acknowledges the receipt of a Vanier Canada Graduate Scholarship. SLE acknowledges the receipt of an NSERC Discovery Grant. The data used in this work were, in part, hosted on facilities supported by the Scientific Computing Core at the Flatiron Institute, a division of the Simons Foundation.
Funding AgencyGrant Number
Vanier Canada Graduate ScholarshipUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Simons FoundationUNSPECIFIED
Subject Keywords:galaxies: evolution – galaxies: fundamental parameters – galaxies: star formation
Issue or Number:1
Record Number:CaltechAUTHORS:20200501-083140063
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Official Citation:Maan H Hani, Christopher C Hayward, Matthew E Orr, Sara L Ellison, Paul Torrey, Norm Murray, Andrew Wetzel, Claude-André Faucher-Giguère, Variations in the slope of the resolved star-forming main sequence: a tool for constraining the mass of star-forming regions, Monthly Notices of the Royal Astronomical Society: Letters, Volume 493, Issue 1, March 2020, Pages L87–L91,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:102955
Deposited By: Tony Diaz
Deposited On:01 May 2020 15:49
Last Modified:01 May 2020 15:49

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