Optical and near-ir spectrophotometry of the galaxy ngc 3310

Abstract

We present spectrophotometric observations in the optical and near-infrared of the nucleus and six H11 regions in the spiral galaxy NGC 3310. Four of the regions are circumnuclear at less than 400 pc from the nucleus, and two are located in the spiral arms at 600 and 1600 pc respectively. Abundance analysis complemented with detailed photoionization models indicates that, while the circumnuclear and disc H II regions have a moderately low metallicity (0.2-0.4 Z̛), the nucleus has solar abundances. No radial gradient was detected away from the nuclear region. The IR Ca II triplet in absorption is observed in some of the H II regions and a moderately strong WR spectral feature at 4686Å in the brightest HII region 9 arcsec SW of the nucleus is also reported. The simultaneous occurrence of these features in H II regions with strong emission lines indicates that star formation lasted a few rnillion years.