An Unbiased Estimate of the Global Hubble Constant in the Region of Pisces‐Perseus

We obtain an unbiased estimate of the global Hubble constant H0 in the volumeof cz<12000km/s in the region of Pisces-Perseus. The Tully-Fisher (TF) relationis applied to a magnitude limited sample of 441 spirals selected from theArecibo 21cm catalog. The photometry data were calibrated with CCD observationsand we achieve 0.13mag for the photometric internal error. We use a maximumlikelihood method for the TF analysis. Monte-Carlo simulations demonstrate thatour method reproduces a given H0 at the 95% confidence level. By applying themethod to our sample galaxies, we obtain the unbiased global Hubble constantH0=65+-2(+20,-14) km/s/Mpc; the first and the second terms represent theinternal random error and the external errors, respectively. We also find agood agreement for our H0 with those recently obtained via Cepheid observation,the TF relation and supernovae. Hubble velocities of the spirals inferred fromour H0 show no significant systematic difference from those given in the MarkIII catalog. The same analysis for H0 is carried out using r-band photometrydata of the Pisces-Perseus region given by Willick et al.(1997). We obtain aglobal H0 which is consistent with that obtained from our B-band analysis. Abulk motion in the Pisces-Perseus region is briefly discussed, based on ourcalibration of H0. Our r-band TF analysis supports the notion of a coherentstreaming motion of the Pisces-Perseus ridge with -200km/s with respect to theCMB, in agreement with most modern studies.Comment: 40 pages, 27 postscript figures, to appear in Ap.J. Figures are included in the tex