A New Determination of the Hubble Constant from Globular Clusters in M87

Abstract

view Abstract Citations (137) References (27) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A New Determination of the Hubble Constant from Globular Clusters in M87 Sandage, Allan Abstract An apparent blue distance modulus of (m - M)AB = 31.1 is derived for the Virgo Cluster from Racine's measurement of B(first) = 21.3 for the brightest globular cluster in M87, using a calibration of MB(first) = -9.83 for cluster B282 in M31. This assumes that the brightest globular clusters in the two galaxies have the same absolute magnitude. The assumption provides an upper limit to H in the present context. For this distance modulus, the absolute luminosity of NGC 4472-the first-ranked E galaxy in the Virgo Cluster-is MB = -21.68. A new redshift-apparent magnitude relation (the Hubble diagram) for first-ranked cluster members (Fig. 1) shows that MB(first) has a remarkably small dispersion of ±0.3 mag in a sample of forty-one clusters. Using MB from NGC 4472 and reading the Hubble diagram at cz = 10~ km sec', which is beyond the local anisotropy in the velocity field, we find that H = 753_~19 km sec' Mpc', using the precepts in the text. Systematic errors are discussed. It seems possible that H could be as small as 50 km sec' Mpc' (H' = 19 X 1O~ years) with the present data. The local anisotropy in the velocity field at the Virgo Cluster is estimated to be ~ = 1.17 ± 0.09. I. INTRODUCTIO Publication: The Astrophysical Journal Pub Date: June 1968 DOI: 10.1086/180201 Bibcode: 1968ApJ...152L.149S full text sources ADS | data products SIMBAD (2) NED (2)