The expansion field: The value of H_0
arXiv:0806.3018 · doi:10.1007/s00159-008-0012-y
Abstract
Any calibration of the present value of the Hubble constant requires recession velocities and distances of galaxies. While the conversion of observed velocities into true recession velocities has only a small effect on the result, the derivation of unbiased distances which rest on a solid zero point and cover a useful range of about 4-30 Mpc is crucial. A list of 279 such galaxy distances within v<2000 km/s is given which are derived from the tip of the red-giant branch (TRGB), from Cepheids, and from supernovae of type Ia (SNe Ia). Their random errors are not more than 0.15 mag as shown by intercomparison. They trace a linear expansion field within narrow margins from v=250 to at least 2000 km/s. Additional 62 distant SNe Ia confirm the linearity to at least 20,000 km/s. The dispersion about the Hubble line is dominated by random peculiar velocities, amounting locally to <100 km/s but increasing outwards. Due to the linearity of the expansion field the Hubble constant H_0 can be found at any distance >4.5 Mpc. RR Lyr star-calibrated TRGB distances of 78 galaxies above this limit give H_0=63.0+/-1.6 at an effective distance of 6 Mpc. They compensate the effect of peculiar motions by their large number. Support for this result comes from 28 independently calibrated Cepheids that give H_0=63.4+/-1.7 at 15 Mpc. This agrees also with the large-scale value of H_0=61.2+/-0.5 from the distant, Cepheid-calibrated SNe Ia. A mean value of H_0=62.3+/-1.3 is adopted. Because the value depends on two independent zero points of the distance scale its systematic error is estimated to be 6%. Typical errors of H_0 come from the use of a universal, yet unjustified P-L relation of Cepheids, the neglect of selection bias in magnitude-limited samples, or they are inherent to the adopted models.
44 pages, 4 figures, 6 tables, accepted for publication in the Astronony and Astrophysics Review 159
References in corpus (20)
- Improved Distances to Type Ia Supernovae with Multicolor Light Curve Shapes: MLCS2k2
- Cosmic clocks, cosmic variance and cosmic averages
- A new calibration of Galactic Cepheid Period-Luminosity relations from B to K bands, and a comparison to LMC PL relations
- Cepheid Parallaxes and the Hubble Constant
- Exact solution to the averaging problem in cosmology
- SFI++ I: A New I-band Tully-Fisher Template, the Cluster Peculiar Velocity Dispersion and H0
- Type Ia Supernovae are Good Standard Candles in the Near Infrared: Evidence from PAIRITEL
- I Zw 18 revisited with HST/ACS and Cepheids: New Distance and Age
- Comparison of Distances from RR Lyrae Stars, the Tip of the Red-Giant Branch and Classical Cepheids
- The Distances to Open Clusters from Main-Sequence Fitting. IV. Galactic Cepheids, the LMC, and the Local Distance Scale
- The distance to the Fornax Dwarf Spheroidal Galaxy
- New period-luminosity and period-color relations of classical Cepheids: III. Cepheids in SMC
- Gravitational energy as dark energy: Concordance of cosmological tests
- The Araucaria Project. The Distance to the Sculptor Galaxy NGC 247 from Near-Infrared Photometry of Cepheid Variables
- Lens Galaxy Properties of SBS1520+530: Insights from Keck Spectroscopy and AO Imaging
- Calibrating Type Ia Supernovae using the Planetary Nebula Luminosity Function I. Initial Results
- The Resolved Stellar Populations of a Dwarf Spheroidal Galaxy in the Virgo Cluster
- Stellar Structure of Irregular Galaxies. Edge-On Galaxies
- Bias Properties of Extragalactic Distance Indicators XII: Bias Effects of Slope Differences and Intrinsic Dispersion on Tully-Fisher Distances to Galaxy Clusters with Application to the Virgo Cluster
- Light Curve Models of Supernovae and X-ray spectra of Supernova Remnants