Circumnuclear Keplerian Disks in Galaxies 1

We have modeled the peculiar bidimensional shape of the emission lines in a sample of four disk galaxies as due to the motion of a gaseous disk rotating in the combined potential of a central point-like mass and of a diffuse stellar disk. From the values we derive for the central masses and the luminosities of the corresponding bulges we obtain a median M•/LB , bulge ∼ 0.16 (in solar units). This value is one order of magnitude larger than the median value derived by Ho (1998) but still within the scatter. Subject headings: galaxies: kinematics and dynamics — galaxies: nuclei — galaxies: individual (NGC 2179, NGC 4343, NGC 4435, NGC 4459, NGC 5064) — galaxies: structure Based on observations carried out at ESO, La Silla, (Chile) (ESO N. 58, A-0564) and on observations with INT operated on the island La Palma by the Royal Greenwich Observatory in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrof́ısica de Canarias, Tenerife, Spain. Dipartimento di Astronomia, Università di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy Osservatorio Astrofisico di Asiago, Dipartimento di Astronomia, Università di Padova, Via dell’Osservatorio 8, I-36012 Asiago, Italy European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Santiago 10, Chile Telescopio Nazionale Galileo, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy