Enhanced star formation – the importance of bars in spiral galaxies

Abstract

IRAS results demonstrate that, amongst intrinsically luminous spiral galaxies, more than one third of the barred systems have an excess of flux at 25μm. The mean total infrared luminosity of these systems (⁠|$4.3\times10^{10}\enspace L_\odot$|⁠) is more than twice that of unbarred galaxies (⁠|$1.7\times10^{10}\enspace L_\odot$|⁠) few or none of which exhibit a 25μm excess. We show that these properties are probably attributable to vigorous star formation in a ‘circumnuclear’ ring located near an inner resonance where material from a bar-driven inflow accumulates, and infer also that an active nucleus does not dominate this phenomenon.