An Hα Imaging Survey of All (Ultra)luminous Infrared Galaxies at Decl. ≥ −30° in the GOALS Sample

Abstract

This paper presents the result of H α imaging for luminous and ultraluminous infrared galaxies. It is a complete subsample of the Great Observatories All-sky LIRG Survey (GOALS) with decl. ≥ −30°, and consists of 148 galaxies with log( L IR / L ☉ ) ≥ 11.0. All the H α images were carried out using the 2.16 m telescope at the Xinglong Station of the National Astronomy Observatories, Chinese Academy of Sciences (NAOC), during the year from 2006 to 2009. We obtained the pure H α luminosity for each galaxy and corrected the luminosity for [N ii ] emission, filter transmission, and extinction. We also classified these galaxies based on their morphology and interaction. We found that the distribution of star-forming regions in these galaxies is related to this classification. As the merging process advanced, these galaxies tended to have a more compact distribution of star-forming regions, higher L IR , and warmer IR-color ( f 60 / f 100 ). These results imply that the degree of dynamical disturbance plays an important role in determining the distribution of a star-forming region.