Detalles de publicación
PP 06019
Halpha Line profiles for a sample of supergiant HII regions.I. The main spectral component
(1).Instituto de Astronomia, Universidad Nacional Autonoma de Mexico,Ensenada, Mexico
(2).Departamento de Fisica Teorica y del Cosmos,Universidad de Granada,Spain
(3).Instituto de Astrofisica de Canarias, Tenerife,Spain. (4) CSIC. Spain
We present an analysis of the emission line profiles of a sample of giant extragalactic HII
regions,selected from among the brightest and most isolated in a group of spiral galaxies for which we have photometric and spectroscopic data:NGC 157,NGC 3631,NGC 6764, NGC 3344,
NGC 4321,NGC 5364, NGC 5055, NGC 5985, NGC 7479. Our study confirms that the majority of
the line profiles are composed of a bright, main component, and two fainter high velocity
components which we denominate wing features. Here we analyze the kinematics of the principal components,finding a relation between the Halpha luminosity L,and the turbulent
velocity dispersion sigma.A linear fit to the relation between them yields
logL = 35.6(+-0.4) + 2.87(+-0.2)log(sigma), in agreement with previous studies by Relan~o
et al.We compute the mass of each HII region using both the virial theorem and the Halpha
luminosity, confirming that though the estimates do not agree exactly, they are comparable
within the uncertainties and that consequently the HII regions in our sample are
approximately virialized.
regions,selected from among the brightest and most isolated in a group of spiral galaxies for which we have photometric and spectroscopic data:NGC 157,NGC 3631,NGC 6764, NGC 3344,
NGC 4321,NGC 5364, NGC 5055, NGC 5985, NGC 7479. Our study confirms that the majority of
the line profiles are composed of a bright, main component, and two fainter high velocity
components which we denominate wing features. Here we analyze the kinematics of the principal components,finding a relation between the Halpha luminosity L,and the turbulent
velocity dispersion sigma.A linear fit to the relation between them yields
logL = 35.6(+-0.4) + 2.87(+-0.2)log(sigma), in agreement with previous studies by Relan~o
et al.We compute the mass of each HII region using both the virial theorem and the Halpha
luminosity, confirming that though the estimates do not agree exactly, they are comparable
within the uncertainties and that consequently the HII regions in our sample are
approximately virialized.