Giant Extragalactic HII Regions in the Southern Sky

FIRPO, VERÓNICA; BOSCH, GUILLERMO; MORRELL, NIDIA

Pucón, Chile

Conferencia; XI IAU Regional Latin American Meeting of Astronomy; 2005

The present work aims to discover the presence of Giant H II Regions (GH IIR) in spiral galaxies of the southern hemisphere sky. We have obtained data of eight luminous H II regions in the galaxies NGC 7552, NGC 6070 and NGC 2997 using the Magellan Inamori Kyocera Echelle spectrograph (MIKE) at the Clay Magellan Telescope (LCO), covering the spectral range 3500-7500 Å resolution R ˜ 60K. The high S/N ratio, together with the resolution of the echelle allowed us to solve the profile of emission lines and to calculate the velocity dispersion of the ionized gas. This analysis was done measuring the observed width of the recombination lines profile after correcting for the instrumental profile and the thermal contribution. We have discovered the giant nature of seven out of the eight candidate regions. These giant H II regions lie, within errors, on the already observed regression in the L- σ plane.