Short GRB Host Galaxies. II. A Legacy Sample of Redshifts, Stellar Population Properties, and Implications for Their Neutron Star Merger Origins
Abstract

We present the stellar population properties of 69 short gamma-ray burst (GRB) host galaxies, representing the largest uniformly modeled sample to date. Using theProspectorstellar population inference code, we jointly fit photometry and/or spectroscopy of each host galaxy. We find a population median redshift of$z=0.64−0.32+0.83$(68% confidence), including nine photometric redshifts atz≳ 1. We further find a median mass-weighted age oftm=$0.8−0.53+2.71$Gyr, stellar mass of log(M*/M) =$9.69−0.65+0.75$, star formation rate of SFR =$1.44−1.35+9.37$Myr−1, stellar metallicity of log(Z*/Z) =$−0.38−0.42+0.44$, and dust attenuation of$AV=0.43−0.36+0.85$mag (68% confidence). Overall, the majority of short GRB hosts are star-forming (≈84%), with small fractions that are either transitioning (≈6%) or quiescent (≈10%); however, we observe a much larger fraction (≈40%) of quiescent and transitioning hosts atz≲ 0.25, commensurate with galaxy evolution. We find that short GRB hosts populate the star-forming main sequence of normal field galaxies, but do not include as many high-mass galaxies as the general galaxy population, implying that their binary neutron star (BNS) merger progenitors are dependent on a combination of host star formation and stellar mass. The distribution of ages and redshifts implies a broad delay-time distribution, more »

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
NSF-PAR ID:
10381098
Journal Name:
The Astrophysical Journal
Volume:
940
Issue:
1
Page Range or eLocation-ID:
Article No. 57
ISSN:
0004-637X
Publisher:
DOI PREFIX: 10.3847
National Science Foundation
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