The circumnuclear environment of the peculiar galaxy NGC3310

GUILLERMO F. HÄGELE; ÁNGELES I. DÍAZ; MÓNICA V. CARDACI; ELENA TERLEVICH; ROBERTO TERLEVICH

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2010 vol. 402 p. 1005 - 1026

0035-8711

Gas and star velocity dispersions have been derived for eight circumnuclear star-formingregions (CNSFRs) and the nucleus of the spiral galaxy NGC3310 using high-resolutionspectroscopy in the blue and far red. Stellar velocity dispersions have been obtained from the Ca II triplet in the near-IR, using cross-correlation techniques, while gas velocity dispersions have been measured by Gaussian fits to the Hβ λ4861Å and [O III] λ5007Å emission lines.The CNSFR stellar velocity dispersions range from 31 to 73 km s−1. These values, togetherwith the sizes measured on archival Hubble Space Telescope images, yield upper limits tothe dynamical masses for the individual star clusters between 1.8 and 7.1 × 106M, for thewhole CNSFR between 2 × 107 and 1.4 × 108Msun, and 5.3 × 107Msun, for the nucleus inside the inner 14.2 pc. The masses of the ionizing stellar population responsible for the HII region gaseous emission have been derived from their published Hα luminosities and are found to be between 8.7 × 105 and 2.1 × 106Msun for the star-forming regions and 2.1 × 105Msun for the galaxy nucleus; they therefore constitute between 1 and 7 per cent of the total dynamical mass.The ionized gas kinematics is complex; two different kinematical components seem to bepresent as evidenced by different linewidths and Doppler shifts.