Steps toward the Hubble constant. V - The Hubble constant from nearby galaxies and the regularity of the local velocity field

1975 ◽  
Vol 196 ◽  
pp. 313 ◽  
Author(s):  
A. Sandage ◽  
G. A. Tammann
Keyword(s):  
Velocity Field ◽  
Hubble Constant ◽  
Local Velocity ◽  
Nearby Galaxies

The Galaxy Motion Relative to Nearby Galaxies and the Local Velocity Field

1996 ◽  
Vol 111 ◽  
pp. 794 ◽  
Author(s):  
I. D. Karachentsev ◽  
D. A. Makarov
Keyword(s):  
Velocity Field ◽  
Local Velocity ◽  
The Galaxy ◽  
Nearby Galaxies

scholarly journals The Local Velocity Field and the Hubble Constant

1996 ◽  
Vol 168 ◽  
pp. 163-173 ◽  
Author(s):  
G. A. Tammann ◽  
Allan Sandage
Keyword(s):  
Velocity Field ◽  
Short Distance ◽  
Hubble Constant ◽  
Virgo Cluster ◽  
Distance Scale ◽  
Cluster Core ◽  
Distance Modulus ◽  
Local Velocity ◽  
The Core ◽  
Cluster Data

The methods are reviewed that give a distance modulus to the core of the Virgo cluster of m - M = 31.64 ± 0.08 (D = 21.3 ± 0.8 Mpc). It is shown that the cosmic velocity of the cluster core is 1179 ± 17 km s−1, which, when combined with the distance gives Ho= 55 ± 3 km s−1Mpc−1from the Virgo cluster data alone. Nine independent methods are reviewed that confirm that Ho= 50 ± 2. Discussion is made why all methods that are said to give the short distance scale (Ho~ 85) are incorrect.

scholarly journals The Hubble Constant and the Deceleration Parameter

1974 ◽  
Vol 63 ◽  
pp. 47-59
Author(s):  
G. A. Tammann
Keyword(s):  
Velocity Field ◽  
Deceleration Parameter ◽  
Preliminary Report ◽  
Hubble Constant ◽  
Intrinsic Properties ◽  
Local Anisotropy ◽  
A Chain ◽  
Distance Indicators ◽  
Luminosity Evolution ◽  
Parent Galaxy

A preliminary report is given of recent work with A. Sandage on the Hubble constant. Through a chain of distance indicators in Sc and Ir galaxies (cepheids, brightest stars, H iiregions, and luminosity classes) the distance scale is carried beyond any possible local anisotropy of the velocity field. Special care is taken to allow for the dependence of the intrinsic properties of the distance indicators on the size of the parent galaxy, and for the effect of the Malmquist correction. H0 is found to be 55 ± 7 km s-1 Mpc-1; within the errors no systematic changes with distance were found.A formal value of the deceleration constant q0 = 1 ± 1 was recently derived by Sandage (1972a) and Sandage and Hardy (1973). The most important correction to this value is probably the luminosity evolution of galaxies, which tends to push q0 below 0.5. The ensuing evidence for an open universe is also favored by independent arguments.

The Local Velocity Field

2008 ◽  
Author(s):  
Karen Masters ◽  
Robert Minchin ◽  
Emmanuel Momjian
Keyword(s):  
Velocity Field ◽  
Local Velocity

scholarly journals The Global Hubble Constant

1990 ◽  
Vol 43 (2) ◽  
pp. 189
Author(s):  
N Visvanathan
Keyword(s):  
Large Scale ◽  
Velocity Dispersion ◽  
Hubble Constant ◽  
Virgo Cluster ◽  
A Value ◽  
Best Value ◽  
Nearby Galaxies ◽  
Distance Data ◽  
Distance Relation

A review of large-scale investigations of the determination of H is presented. The infrared period-luminosity relation of Cepheids gives distances accurate to -2% to nearby galaxies. Based on the distances of M31, MH, N300 and N2403, a DM of 31 �30 �O� 20 has been derived to the nearby Virgo cluster from the TF relation of spirals at four wavebands. Distances to more distant clusters extending up to a redshift of -10000 km S-I obtained through the CM relation of E galaxies, the TF relation of spirals and the velocity dispersion-luminosity relation of E galaxies give a value of H of 71 km S-I Mpcl when these distances are normalised to a Virgo DM of 31�30. The scatter in the redshift-distance relation of these clusters is -500 km s-I arising from the presence of unaccounted peculiar motions of individual clusters. The magnitude limited all-sky samples of galaxies also give a value of H near 70 km S-I Mpcl once the data are corrected for Malmquist bias. The best value of the global Hubble constant obtained from the redshift-distance data of Virgo and farther clusters, as well as the magnitude limited samples involving various methods of determining distances by different observers, is 73 km S-i Mpcl . Taking into account the error in the calibration of our DM of Virgo we can set a generous error of 10 to this value of H.

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