1302.6236 (J. E. Geach et al.)

A redline starburst: CO(2-1) observations of an Eddington-limited galaxy reveal star formation at its most extreme    [PDF]

J. E. Geach, R. C. Hickox, A. M. Diamond-Stanic, M. Krips, J. Moustakas, C. A. Tremonti, A. L. Coil, P. H. Sell, G. H. Rudnick

We report observations of the CO(2-1) emission of SDSSJ1506+54, a compact (r_e~135pc) starburst galaxy at z=0.6. SDSSJ1506+54 appears to be forming stars close to the limit allowed by stellar radiation pressure feedback models: the measured L_IR/L'_CO 1500 is one of the highest measured for any galaxy. With its compact optical morphology but extended low surface brightness envelope, post-starburst spectral features, high infrared luminosity (L_IR>10^12.5 L_Sun), low gas fraction (M_H2/M_stars~15%), and short gas depletion time (tens of Myr), we speculate that this is a feedback- limited central starburst episode at the conclusion of a major merger. Taken as such, SDSSJ1504+54 epitomizes the brief closing stage of a classic model of galaxy growth: we are witnessing a key component of spheroid formation during what we term a 'redline' starburst.

View original: http://arxiv.org/abs/1302.6236