Stellar kinematics and the stability of disks in spiral galaxies

Abstract

view Abstract Citations (116) References (37) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Stellar Kinematics and the Stability of Disks in Spiral Galaxies van der Kruit, P. C. ; Freeman, K. C. Abstract The authors have observed the velocity dispersion of the old disk population in two spiral galaxies. In the face-on Sc spiral NGC 5247, the radial decline of the vertical velocity dispersion >VZ2<1/2 from the center to about two disk scale lengths is consistent with that predicted for a disk of constant thickness and M/L ratio. Combined with earlier results, the (M/L)B value for the old disk is 6±2 solar units. For the edge-on Sb spiral NGC 7184, the authors have measured the asymmetric drift and the absorption line profile widths, which show that the radial velocity dispersion >VR2<1/2 also decreases with radius. In the inner regions, the velocity dispersion contributes significantly to the global disk stability. The observational results are compared with various theoretical stability parameters and numerical simulations of model galaxies. Publication: The Astrophysical Journal Pub Date: April 1986 DOI: 10.1086/164102 Bibcode: 1986ApJ...303..556V Keywords: Disk Galaxies; Galactic Structure; Spiral Galaxies; Star Distribution; Stellar Motions; Astronomical Spectroscopy; Gravitational Collapse; Mass Distribution; Mass To Light Ratios; Milky Way Galaxy; Radial Velocity; Systems Stability; Astrophysics; GALAXIES: INTERNAL MOTIONS; GALAXIES: STELLAR CONTENT; GALAXIES: STRUCTURE full text sources ADS | data products SIMBAD (8) NED (5)