High-velocity Outflows without AGN Feedback: Eddington-limited Star Formation in Compact Massive Galaxies
Moustakas, John; Coil, Alison L.; Rudnick, Gregory H.; Robaina, Aday R.; Tremonti, Christy A.; Diamond-Stanic, Aleksandar M.; Hickox, Ryan C.; Sell, Paul H.
United States, France, Spain
Abstract
We present the discovery of compact, obscured star formation in galaxies at z ~ 0.6 that exhibit >~ 1000 km s-1 outflows. Using optical morphologies from the Hubble Space Telescope and infrared photometry from the Wide-field Infrared Survey Explorer, we estimate star formation rate (SFR) surface densities that approach ΣSFR ≈ 3000 M ⊙ yr-1 kpc-2, comparable to the Eddington limit from radiation pressure on dust grains. We argue that feedback associated with a compact starburst in the form of radiation pressure from massive stars and ram pressure from supernovae and stellar winds is sufficient to produce the high-velocity outflows we observe, without the need to invoke feedback from an active galactic nucleus.