An unbiased estimate of the global hubble constant in the region of pisces-perseus

Masaru Watanabe, Takashi Ichikawa, Sadanori Okamura

研究成果: Article査読

2 被引用数 (Scopus)


We obtain an unbiased estimate of the global Hubble constant H0 in a volume of cz ≤ 12, 000 km s-1 in the region of Pisces-Perseus. The Tully-Fisher (TF) relation is applied to a magnitude-limited sample of 441 spiral galaxies selected from the Arecibo 21 cm catalog. We improve the photometry data of the previous TF study by Ichikawa & Fukugita by using our original surface photometry data and local calibrators that have newly been made available in other works. The photometry data were calibrated with CCD observations, and we achieve 0.13 mag for a photometric internal error. We use a maximum likelihood method for the TF analysis. Monte Carlo simulations demonstrate that our method reproduces a given H0 at the 95% confidence level. By applying the method to our sample galaxies, we obtain the unbiased global Hubble constant H0 = 65±2-14+20 km s-1 Mpc-1; the first and the second terms represent the internal random error and the external uppermost and lowermost systematic errors, respectively. We also find a good agreement for our H0 with those recently obtained via Cepheid observation in the local universe and the TF relation and supernovae applied to a spatial volume comparable to or larger than ours. Hubble velocities of the spirals inferred from our H0 show no significant systematic differences from those given in the Mark III catalog. The same analysis for H0 is carried out using the r-band photometry data of the Pisces-Perseus region given by Willick et al. We obtain a global H0 that is consistent with that obtained from the B-band analysis. A bulk motion in the Pisces-Perseus region is briefly discussed, based on our calibration of H0. The B-band intrinsic TF scatter is too large to allow any determination of bulk motion. However, our r-band TF analysis supports the notion of a coherent streaming motion of the Pisces-Perseus ridge with a velocity of ∼- 200 km s-1 with respect to the CMB, in agreement with most modern studies.

ジャーナルAstrophysical Journal
出版ステータスPublished - 1998

ASJC Scopus subject areas

  • 天文学と天体物理学
  • 宇宙惑星科学


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