The Hubble Diagram in V for Supernovae of Type IA and the Value of H 0 Therefrom
Abstract
The Hubble diagram for supernovae of Type Ia is derived in V and is summarized from the literature in m_pg_ and in B. The ridge line equation of the diagram in V is log v_220_ = 0.2 m_v_ + (0.653 +/- 0.012) from 34 SNe Ia. The dispersion of a single point about the ridge line is 0.36 mag. We argue from external evidence that the intrinsic dispersion is likely to be as small or smaller than σ)v_(max) = 0.2 mag. The intrinsic (B - V) color at B maximum light is 0.09 +/- 0.04 mag. The calibration of the absolute magnitudes at maximum from four concordant methods, including the determination for SN 1937C via Cepheids in IC 4182, is <M_B_(max)> = - 19.55 +/- 0.14 and M__V_(max) = - 19.71 +/- 0.13. These values lead to the long distance scale with <H_0_> between 45 and 52 km s^-1^ Mpc^-1^. This range depends on whether we use (1) the SN Hubble diagrams in the m_pg_, B, and V bands themselves from Figure 1, or (2) the derived virgo Cluster distance of 23.9 +/- 2.4 Mpc found from the SN 1937C calibration alone at M_V_(max) = - 19.76, applied to the six SNe Ia with adequate V photometry that have appeared in the cluster with <V(max)> = 12.13 +/- 0.14. By the precepts previously developed for the Virgo velocity relative to the cosmic frame (Sandage & Tammann 1990; Jerjen & Tammann 1992), this Virgo distance gives the cosmic value of the Hubble constant to be H_0_ = 47 +/- 5 km s^-1^ Mpc^-1^.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1993
- DOI:
- 10.1086/173137
- Bibcode:
- 1993ApJ...415....1S
- Keywords:
-
- Cepheid Variables;
- Galactic Structure;
- Hubble Space Telescope;
- Supernovae;
- Astronomical Photometry;
- Calibrating;
- Astrophysics;
- COSMOLOGY: DISTANCE SCALE;
- STARS: SUPERNOVAE: GENERAL