J/ApJ/931/51 Subaru/HSC imaging of SQuIGGLE z~0.7 galaxies (Setton+, 2022) ================================================================================ The compact structures of massive z~0.7 post-starburst galaxies in the SQuIGGLE. Setton D.J., Verrico M., Bezanson R., Greene J.E., Suess K.A., Goulding A.D., Spilker J.S., Kriek M., Feldmann R., Narayanan D., Hall-Hooper K., Kado-Fong E. =2022ApJ...931...51S ================================================================================ ADC_Keywords: Galaxies, optical; Redshifts; Morphology; Galaxies, radius; Surveys Keywords: Post-starburst galaxies ; Galaxy quenching ; Galaxy evolution ; Quenched galaxies ; Galaxies Abstract: We present structural measurements of 145 spectroscopically selected intermediate-redshift (z~0.7), massive (M_*_~10^11^M_{sun}_) post-starburst galaxies from the SQuIGG->LE sample measured using wide-depth Hyper Suprime-Cam i-band imaging. This deep imaging allows us to probe the sizes and structures of these galaxies, which we compare to a control sample of star-forming and quiescent galaxies drawn from the LEGA-C Survey. We find that post-starburst galaxies systematically lie ~0.1dex below the quiescent mass-size (half-light radius) relation, with a scatter of ~0.2dex. This finding is bolstered by nonparametric measures, such as the Gini coefficient and the concentration, which also reveal these galaxies to have more compact light profiles than both quiescent and star-forming populations at similar mass and redshift. The sizes of post-starburst galaxies show either negative or no correlation with the time since quenching, such that more recently quenched galaxies are larger or similarly sized. This empirical finding disfavors the formation of post-starburst galaxies via a purely central burst of star formation that simultaneously shrinks the galaxy and shuts off star formation. We show that the central densities of post-starburst and quiescent galaxies at this epoch are very similar, in contrast with their effective radii. The structural properties of z~0.7 post-starburst galaxies match those of quiescent galaxies that formed in the early universe, suggesting that rapid quenching in the present epoch is driven by a similar mechanism to the one at high redshift. Description: The SQuIGGLE sample (Suess+ 2022, J/ApJ/926/89) is selected from the SDSS DR14 spectroscopic sample (Abolfathi+ 2018ApJS..235...42A); see Section 2.1 and the LEGA-C Survey DR3 (van der Wel+ 2021, J/ApJS/256/44); see Section 2.2. Using i-band images from the HSC survey, we study the sizes and structures of z~0.7 post-starburst galaxies. See Section 2.3. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 130 145 Structural and selected spectrophotometric properties of SQuIGGLE post-starburst galaxies table2.dat 94 145 Uncertainties on Sersic parameters from PSF model refitting -------------------------------------------------------------------------------- See also: V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020) J/ApJ/588/218 : i*g* photometry of SDSS EDR galaxies (Abraham+, 2003) J/ApJS/147/1 : Classification of nearby galaxies (Conselice+, 2003) J/ApJ/749/121 : Surface brightness profiles if z=2 galaxies (Szomoru+, 2012) J/ApJS/203/24 : Structural param. of galaxies in CANDELS (van der Wel+, 2012) J/ApJ/777/18 : Stellar mass functions of galaxies to z=4 (Muzzin+, 2013) J/ApJ/833/19 : 0.02