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The HST Key Project on the Extragalactic Distance Scale. XXVIII. Combining the Constraints on the Hubble Constant

Jeremy R Mould·John P Huchra·Wendy L Freedman·Robert C Kennicutt Jr·Laura Ferrarese·Holland C Ford·Brad K Gibson·John A Graham·Shaun Hughes·Garth D Illingworth·Daniel D Kelson·Lucas M Macri·Barry F Madore·Shoko Sakai·Kim Sebo·Nancy A Silbermann·Peter B Stetson
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Abstract

Since the launch of the Hubble Space Telescope nine years ago, Cepheid distances to 25 galaxies have been determined for the purpose of calibrating secondary distance indicators. A variety of these can now be calibrated, and the accompanying papers by Sakai, Kelson, Ferrarese, and Gibson employ the full set of 25 galaxies to consider the Tully-Fisher relation, the fundamental plane of elliptical galaxies, Type Ia supernovae, and surface brightness fluctuations. When calibrated with Cepheid distances, each of these methods yields a measurement of the Hubble constant and a corresponding measurement uncertainty. We combine these measurements in this paper, together with a model of the velocity field, to yield the best available estimate of the value of H_0 within the range of these secondary distance indicators and its uncertainty. The result is H_0 = 71 +/- 6 km/sec/Mpc. The largest contributor to the uncertainty of this 67% confidence level result is the distance of the Large Magellanic Cloud, which has been assumed to be 50 +/- 3 kpc.

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Jeremy R Mould, John P Huchra, Wendy L Freedman, Robert C Kennicutt Jr, Laura Ferrarese, Holland C Ford, Brad K Gibson, John A Graham, Shaun Hughes, Garth D Illingworth, Daniel D Kelson, Lucas M Macri, Barry F Madore, Shoko Sakai, Kim Sebo, Nancy A Silbermann, Peter B Stetson. 1999-09-15. The HST Key Project on the Extragalactic Distance Scale. XXVIII. Combining the Constraints on the Hubble Constant. https://doi.org/10.1086/308304

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