Velocity dispersions in the bulges of spiral galaxies

Abstract

view Abstract Citations (136) References (45) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Velocity dispersions in the bulges of spiral galaxies. Whitmore, B. C. ; Kirshner, R. P. ; Schechter, P. L. Abstract Velocity dispersions have been obtained in the central regions of 30 galaxies, 21 of which are spirals. Spectra were obtained at McGraw-Hill Observatory with an intensified Reticon scanner. A 'Fourier quotient' technique was used to yield dispersions, with typical uncertainties in the central velocity dispersions of 22 km/s. It is found that the spheroidal bulges of spiral galaxies obey the same L equals sigma to the 4th relation between luminosity and velocity dispersion that has been found in ellipticals, but with dispersions smaller by 15% at a given absolute magnitude. This may be understood as a difference in mass-to-light ratio, a difference in rotational support, or a difference in central surface brightness. The bulge dispersions are compared with neutral hydrogen velocity widths and it is found that if most of the mass of spiral galaxies is in a dark isothermal component, the bulge is somewhat cooler than this halo. Publication: The Astrophysical Journal Pub Date: November 1979 DOI: 10.1086/157473 Bibcode: 1979ApJ...234...68W Keywords: Galactic Nuclei; Galactic Structure; Spiral Galaxies; Velocity Distribution; Astronomical Spectroscopy; Elliptical Galaxies; Luminous Intensity; Optical Emission Spectroscopy; Astrophysics; Galaxies:Velocity Distribution full text sources ADS | data products NED (31)