Dust Temperature of Compact Star-forming Galaxies at $ z \sim 1-3$ in 3D-{\it HST}/CANDELS

TL;DR

This study investigates dust temperatures in compact and extended star-forming galaxies at redshifts 1-3, finding similar dust properties regardless of morphology and minimal AGN influence, challenging the necessity of rapid compaction for galaxy formation.

Contribution

It provides the first detailed comparison of dust temperatures between compact and extended SFGs at high redshift, showing similar dust properties and questioning the role of rapid compaction.

Findings

Dust temperatures follow similar evolutionary tracks for both galaxy types.

Compact SFGs have comparable dust temperatures to extended SFGs.

AGN presence does not significantly affect dust properties in compact SFGs.

Abstract

Recent simulation studies suggest that the compaction of star-forming galaxies (SFGs) at high redshift might be a critical process, during which the central bulge is being rapidly built, followed by quenching of the star formation. To explore dust properties of SFGs with compact morphology, we investigate the dependence of dust temperature, $T_{\rm{dust}}$, on their size and star formation activity, using a sample of massive SFGs with $\log (M_{\ast}/M_{\odot}) > 10$ at $1 < z < 3$, drawn from the 3D-{\it HST}/CANDELS database in combination with deep {\it Herschel} observations. $T_{\rm{dust}}$ is derived via fitting the mid-to-far-infrared photometry with a mid-infrared power law and a far-infrared modified blackbody. We find that both extended and compact SFGs generally follow a similar $T_{\rm{dust}}-z$ evolutionary track as that of the main-sequence galaxies. The compact SFGs seem to share similar dust temperature with extended SFGs. Despite the frequent occurrence of AGNs in compact SFGs, we do not observe any effect on dust caused by the presence of AGN in these galaxies during the compaction. Our results disfavor different ISM properties between compact and extended SFGs, suggesting that a rapid and violet compaction process might be not necessary for the formation of compact SFGs.