TY - JOUR
T1 - Variations in the slope of the resolved star-forming main sequence
T2 - A tool for constraining the mass of star-forming regions
AU - Hani, Maan H.
AU - Hayward, Christopher C.
AU - Orr, Matthew E.
AU - Ellison, Sara L.
AU - Torrey, Paul
AU - Murray, Norm
AU - Wetzel, Andrew
AU - Faucher-Giguère, Claude André
N1 - Funding Information:
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.
Publisher Copyright:
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2020/1/28
Y1 - 2020/1/28
N2 - 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 (αMS) 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' αMS on spatial resolution and use it to illustrate how this dependence can be used to constrain the characteristic mass of star-forming clumps.
AB - 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 (αMS) 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' αMS on spatial resolution and use it to illustrate how this dependence can be used to constrain the characteristic mass of star-forming clumps.
KW - galaxies: evolution
KW - galaxies: fundamental parameters
KW - galaxies: star formation
UR - http://www.scopus.com/inward/record.url?scp=85081979450&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85081979450&partnerID=8YFLogxK
U2 - 10.1093/mnrasl/slaa013
DO - 10.1093/mnrasl/slaa013
M3 - Article
AN - SCOPUS:85081979450
VL - 493
SP - L87-L91
JO - Monthly Notices of the Royal Astronomical Society: Letters
JF - Monthly Notices of the Royal Astronomical Society: Letters
SN - 1745-3933
IS - 1
ER -