New Velocity Dispersions and Photometry for E and S0 Galaxies in the Great Attractor
Abstract
New spectroscopy and photometry have been obtained for 136 elliptical and S0 galaxies in the direction of the large-scale streaming flow attributed to the great attractor. Measurements of central velocity dispersion (σ), total B magnitudes (B_r_), the photometric parameter Deta_ , and the absorption-line index Mg_2_ are presented. Both internal and external comparisons indicate that measurements of log σ are accurate to 0.05 dex, B_T_ to 0.15 mag, Deta_ to 0.015 dex, and Mg_2_ to 0.017 mag. These data have been used in a previous paper by Dressler and Faber to estimate distances for these galaxies via the Deta_-σ relation. It is shown in this paper that the Deta_-Mg_2_ relation also predicts the same trends of peculiar velocity with distance, but with less accuracy. The relative accuracy of other distance indicators for elliptical galaxies is also discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1991
- DOI:
- Bibcode:
- 1991ApJ...368...54D
- Keywords:
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- Astronomical Photometry;
- Elliptical Galaxies;
- Spiral Galaxies;
- Strange Attractors;
- Absorption Spectra;
- Astronomical Catalogs;
- Galactic Clusters;
- Hubble Diagram;
- Red Shift;
- Astrophysics;
- GALAXIES: DISTANCES;
- GALAXIES: INTERNAL MOTIONS;
- GALAXIES: PHOTOMETRY