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Astron. Astrophys. 347, 99-111 (1999)

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Kinematics of the local Universe

X. H0 from the inverse B-band Tully-Fisher relation using diameter and magnitude limited samples

T. Ekholm 1,4, P. Teerikorpi 1, G. Theureau 2,3, M. Hanski 1, G. Paturel 4, L. Bottinelli 3 and L. Gouguenheim 3

1 Tuorla Observatory, FIN-21500 Piikkiö, Finland
2 Osservatorio Astronomico di Capodimonte, I-80 131 Napoli, Italy
3 Observatoire de Paris-Meudon, CNRS URA1757, F-92195 Meudon Principal Cedex, France
4 Observatoire de Lyon, F-69561 Saint-Genis Laval Cedex, France

Received 14 September 1998 / Accepted 16 April 1999


We derive the value of [FORMULA] using the inverse diameter and magnitude B-band Tully-Fisher relations and the large all-sky sample KLUN (5171 spiral galaxies). Our kinematical model was that of Peebles centered at Virgo. Our calibrator sample consisted of 15 field galaxies with cepheid distance moduli measured mostly with HST. A straightforward application of the inverse relation yielded [FORMULA] for the diameter relation and [FORMULA] for the magnitude relation. [FORMULA] from diameters is about 50 percent and from magnitudes about 30 percent larger than the corresponding direct estimates (cf. Theureau et al. 1997b). This discrepancy could not be resolved in terms of a selection effect in [FORMULA] nor by the dependence of the zero-point on the Hubble type.

We showed that a new, calibrator selection bias (Teerikorpi et al. 1999), is present. By using samples of signicificant size (N=2142 for diameters and N=1713 for magnitudes) we found for a homogeneous distribution of galaxies ([FORMULA]):

  • [FORMULA] for the inverse diameter B-band Tully-Fisher relation, and

  • [FORMULA] for the inverse magnitude B-band Tully-Fisher relation.

Also [FORMULA]'s from a fractal distribution of galaxies (decreasing radial number density gradient [FORMULA]) agree with the direct predictions. This is the first time when the inverse Tully-Fisher relation clearly lends credence to small values of the Hubble constant [FORMULA] and to long cosmological distance scale consistently supported by Sandage et al. (1995).

Key words: galaxies: distances and redshifts – galaxies: spiral – cosmology: distance scale

Send offprint requests to: T. Ekholm

© European Southern Observatory (ESO) 1999

Online publication: June 18, 1999