Clumpology of Starbursts in the WiggleZ Dark Energy Survey

TL;DR

This study uses adaptive optics to observe star-forming galaxies at z~1.2-1.5, revealing diverse Halpha emission structures and evidence of unstable gaseous disks with ordered motion.

Contribution

First detailed adaptive optics observations of Halpha emission in WiggleZ galaxies, showing complex clump structures and disk dynamics at high redshift.

Findings

Detection of multiple Halpha clumps in 4 galaxies

Evidence of ordered orbital motion in most galaxies

Diverse emission morphologies including extended and spheroidal

Abstract

We have observed Halpha emission from a sample of 13 star-forming galaxies from the WiggleZ Dark Energy Survey in the redshift range z~1.2-1.5 and stellar mass range 9.8<log(M_*/M_sun)<11.6 with the integral field spectrograph OSIRIS on Keck, taking advantage of Laser Guide Star Adaptive Optics. We detect multiple emission, 1-2 kpc size sub-components, or 'clumps' within the Halpha spatial emission in 4 galaxies, extended emission in 4 galaxies and compact spheroidal emission in 5 galaxies. Considering our results in the context of unstable disk formation and a merger sequence, we find evidence of ordered orbital motion in the majority of galaxies as would be found in unstable gaseous disks.