CO Tully-Fisher Relation of Star-forming Galaxies at z=0.05-0.3

TL;DR

This study presents the first CO-based Tully-Fisher relations for star-forming galaxies at z=0.05-0.3, showing no significant evolution since z=0.3, and confirms CO as a viable kinematic tracer.

Contribution

It introduces the first CO Tully-Fisher relations for galaxies beyond the local universe and demonstrates their consistency with local relations.

Findings

No significant evolution in TFR slopes and zero-points since z=0.3

CO is a suitable alternative to HI for TFR studies

Provides a benchmark for future high-redshift CO TFR research

Abstract

The Tully-Fisher relation (TFR) is an empirical relation between galaxy luminosity and rotation velocity. We present here the first TFR of galaxies beyond the local Universe that uses carbon monoxide (CO) as the kinematic tracer. Our final sample includes 25 isolated, non-interacting star-forming galaxies with double-horned or boxy CO integrated line profiles located at redshifts z <= 0.3, drawn from a larger ensemble of 67 detected objects. The best reverse Ks-band, stellar mass and baryonic mass CO TFRs are respectively M_Ks = (-8.4+/-2.9) [log(W_50/sini)-2.5]+(-23.5 +/- 0.5), log (Mstar/Msun) =(5.2+/-3.0) [log(W_50/sini)-2.5]+(10.1+/-0.5) and log (Mb/Msun) = (4.9+/-2.8) [log(W_50/sini)-2.5]+(10.2+/-0.5), where M_Ks is the total absolute Ks-band magnitude of the objects, Mstar and Mb their total stellar and baryonic masses, and W_50 the width of their line profile at 50% of the maximum. Dividing the sample into different redshift bins and comparing to the TFRs of a sample of local (z = 0) star-forming galaxies from the literature, we find no significant evolution in the slopes and zero-points of the TFRs since z = 0.3, this in either luminosity or mass. In agreement with a growing number of CO TFR studies of nearby galaxies, we more generally find that CO is a suitable and attractive alternative to neutral hydrogen (HI). Our work thus provides an important benchmark for future higher redshift CO TFR studies.