Evidence of a starburst within 9 parsecs of the active nucleus of NGC 1097

Abstract

We report evidence of a recent burst of star formation located within 9 pc of the active nucleus of NGC 1097. The observational signatures of the starburst include UV absorption lines and continuum emission from young stars observed in a small-aperture Hubble Space Telescope spectrum. The burst is ≤ a few x10 6 yr old, has a mass of ∼10 6 Mʘ, an observed luminosity of 1.5x10 7Lʘ, and is obscured by Av ≈ 3 mag. The importance of V this finding is twofold: (1) the proximity of the starburst to the active nucleus and thus its possible association with it, and (2) its obscuration by and apparent association with a dusty absorbing medium, while the broad emission lines appear unobscured, suggesting that the starburst could be embedded in a circumnuclear torus as predicted in the unified model of active galactic nuclei.