THE STARBURST GALAXY NGC-7714

Narrowband H alpha imaging and long-slit optical and near-infrared spe ctroscopy are analyzed in a study of the starburst galaxy NGC 7714. Th e data indicate that the galaxy as a whole is experiencing intense sta r formation activity; this is more conspicuous in the nucleus, where t he star formation rate and the star formation rate per unit area are h igher than in the rest of the galaxy. Evidence for this intense star f ormation activity comes from the detection of broad emission He II lam bda 4686, attributed to WN stars; this suggests an age of the present burst between 3 and 5 Myr. Evidence of the existence of previous burst s come from the detection of the infrared Ca II triplet in absorption, which indicates the presence of red giant or supergiant stars. Spectr oscopic data are taken at two position angles (P.A. = 110 degrees and 216 degrees) across the nucleus and comprise also three giant H II reg ions located in the circumnuclear region and in the spiral arms, The p hysical conditions and chemical composition of the gas are derived. Ab undances are moderately low, with an excess of N in and around the nuc leus. The velocity curve at P.A. = 216 degrees is very distorted, indi cating large departures from circular motion. Higher velocity dispersi on of the gas in the circumnuclear region has also been found and coul d be related to enhanced star formation.