Infrared surface brightness and absolute magnitude of spiral galaxies
Abstract
It is shown that absolute magnitudes of spiral galaxies predicted from their infrared surface brightness (sigma) have standard deviations of only 0.94 mag. M31 and M33 are used as calibrators for the sigma versus M(H) relation in the Virgo cluster, which yields H(local) = 49 and 62 km/s/Mpc from M31 and M33, respectively. Aaronson's et al. (1980) calibration of the observations in four distant clusters yields H(global) = 92 and 115 km/s/Mpc from M31 and M33, respectively. The infrared surface brightness data suggest that the Virgo cluster is at 1.86 + or - 0.14(m.e.) times the distance suggested by its redshift. The result indicates a large local velocity perturbation, which might be explained by assuming that (1) Virgo galaxies are more compact than those in the four more distant clusters that have so far been studied, or (2) that some problem exists with the photometry and/or diameter determinations of galaxies in at least two of the distant clusters studied by Aaronson et al.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1981
- DOI:
- 10.1086/183612
- Bibcode:
- 1981ApJ...248L...9V
- Keywords:
-
- Astronomical Photometry;
- Brightness;
- Galactic Radiation;
- Infrared Astronomy;
- Spiral Galaxies;
- Andromeda Galaxy;
- Calibrating;
- Galactic Clusters;
- Luminous Intensity;
- Astrophysics