Extragalactic distance scale, Malmquist bias and Hubble constant
نویسندگان
چکیده
منابع مشابه
Anisotropy in the Hubble constant as observed in the HST Extragalactic Distance Scale Key Project results
Based on general relativity, it can be argued that deviations from a uniform Hubble flow should be thought of as variations in the Universe’s expansion velocity field, rather than being thought of as peculiar velocities with respect to a uniformly expanding space. The aim of this paper is to use the observed motions of galaxies to map out variations in the Universe’s expansion, and more importa...
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The Malmquist bias in luminosity distances for gaussian standard candles is discussed within cosmological models where the Euclidean r3-law for volumes and r−2-law for fluxes is not valid. Furthermore, the influence of K-corrections and luminosity evolution are analyzed. It is noted that the usual way of comparing theoretical predictions and data points in the Hubble diagram (log z vs. m) shoul...
متن کاملThe Extragalactic Distance Scale
Significant progress has been made during the last 10 years toward resolving the debate over the expansion rate of the Universe. The current value of the Hubble parameter, H 0, is now arguably known with an accuracy of 10%, largely due to the tremendous increase in the number of galaxies in which Cepheid variable stars have been discovered. Increasingly accurate secondary distance indicators, m...
متن کاملThe Extragalactic Distance Scale
Cepheid variables are used to derive a Virgo cluster distance of 16.0 ± 1.5 Mpc. In conjunction with the Coma velocity and the well-established Coma/Virgo distance ratio, this yields a Hubble parameter H = 81 ± 8 km s o-1 Mpc. By combining this value with an age of the Universe / 16.8 ± 2.1 Gyr, that-1 is derived from the metal-poor globular cluster M92, one obtains f (5, %) / 1.39 ± 0.22. This...
متن کاملThe Hubble Space Telescope Key Project on the Extragalactic Distance Scale Xxiv: the Calibration of Tully–fisher Relations and the Value of the Hubble Constant
This paper presents the calibration of BVRIH−0.5 Tully–Fisher relations based on Cepheid distances to 21 galaxies within 25 Mpc, and 23 clusters within 10,000 km s−1. These relations have been applied to several distant cluster surveys in order to derive a value for the Hubble constant, H0, mainly concentrating on an I–band all–sky survey by Giovanelli and collaborators which consisted of total...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1983
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/202.2.367