The Hubble Flow from Brightest Cluster Galaxies
Abstract
We have imaged 114 Brightest Cluster Galaxies (BCG) from a full-sky sample of all Abell clusters within 15,000 km s^-1^. We present a BCG distance indicator based on reexamination of the Hoessel relationship between BCG metric luminosity and structure. The BCG Hubble diagram is consistent with a uniform Hubble flow over 0.01 <= z <= 0.05. We limit any variation in the apparent H_0_ (measured globally from our location) to {DELTA}H_0_/H_0_ < 0.07 across the same volume. We use the Virgo BCG, NGC 4472, to calibrate the BCG Hubble diagram directly, independent of the Virgocentric infall pattern. For the observed distance to NGC 4472 of 14.4 Mpc, H_0_ = 77+/-8 km s^-1^ Mpc^-1^. Alternatively, if NGC 4472 is at the Sandage & Tammann 21.9 Mpc distance to Virgo, then H_0_ = 51+/-5. The BCG Hubble constant on either the short or long system is consistent with Hubble constants measured on the same system within the local supercluster. Plausible high values of H_0_ observed within the local supercluster therefore cannot be explained as biased measures of the true H_0_ due to velocity anomalies induced by large-scale structure.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1992
- DOI:
- 10.1086/186646
- Bibcode:
- 1992ApJ...400L..47L
- Keywords:
-
- Cosmology;
- Galactic Clusters;
- Hubble Diagram;
- Universe;
- Astronomical Photometry;
- Hubble Constant;
- Local Group (Astronomy);
- Luminosity;
- Sky Surveys (Astronomy);
- Astrophysics;
- COSMOLOGY: DISTANCE SCALE;
- COSMOLOGY: LARGE-SCALE STRUCTURE OF UNIVERSE;
- GALAXIES: FUNDAMENTAL PARAMETERS