Radiation Pressure Feedback in Galaxies

¹ Department of Astronomy, The Ohio State University, USA
e-mail: andrews@astronomy.ohio-state.edu & thompson@astronomy.ohio-state.edu
² The Center for Cosmology and Astroparticle Physics, The Ohio State University, USA

Abstract

We evaluate radiation pressure from starlight on dust as a feedback mechanism in star-forming galaxies by comparing the luminosity and flux of star-forming systems to the dust Eddington limit. The linear L_FIR–${\mathit{L}}_{\mathrm{HCN}}^{\mathrm{\prime }}$ correlation provides evidence that galaxies may be regulated by radiation pressure feedback. We show that star-forming galaxies approach but do not dramatically exceed Eddington, but many systems are significantly below Eddington, perhaps due to the “intermittency” of star formation. Better constraints on the dust-to-gas ratio and the CO- and HCN-to-H₂ conversion factors are needed to make a definitive assessment of radiation pressure as a feedback mechanism.