Variations in the slope of the resolved star-forming main sequence: a tool for constraining the mass of star-forming regions
Abstract
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.
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 (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_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.Attached Files
Published - slaa013.pdf
Accepted Version - 1912.04290.pdf
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Additional details
- Eprint ID
- 102955
- Resolver ID
- CaltechAUTHORS:20200501-083140063
- Vanier Canada Graduate Scholarship
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- Simons Foundation
- Created
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2020-05-01Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- TAPIR