Physical Parameters in Circumnuclear Star Forming Regions

G.F. HÄGELE, M.V. CARDACI, A.I. DÍAZ, E. TERLEVICH, R. TERLEVICH AND M. CASTELLANOS

Cariló, Argentina

Congreso; Massive Stars: Fundamental Parameters and Circumstellar Interactions; 2006

Facultad de Ciencias Astronómicas y Geofísicas de La Plata

We present spectroscopy observations of circumnuclear star forming regions (CNSFR) in the galaxies: NGC 2903, NGC 3351 and NGC 3504, all of them of over solar metallicity according to standard empirical calibrations. Using data of moderate resolution (R\,$\sim$\,9000) a detailed determination of their abundances is made after careful subtraction of the very prominent underlying stellar absorption. It is found that most regions show the highest abundances in HII region-like objects. It is also shown that  CNSFR,  as a class, segregate from the disk HII region family, clustering around smaller$\eta$\ values, and therefore higher ionizing temperatures.High resolution (R\,$\sim$\,23000) data are used to map the velocity fieldin the central Kpc of one of the galaxies, NGC 3351, and to measure ionized gas (H$\beta$) and stellar (Ca triplet) velocity dispersions for individual CNSFRs.