Masses of the local group and of the M81 group estimated from distortions in the local velocity field |
| |
| Authors: | I D Karachentsev O G Kashibadze |
| |
| Institution: | (1) Special Astrophysical Observatory, Russian Academy of Sciences, Russia;(2) P. K. Shternberg State Astronomical Institute, Russia |
| |
| Abstract: | Based on high precision measurements of the distances to nearby galaxies with the Hubble telescope, we have determined the
radii of the zero velocity spheres for the local group, R0 = 0.96±0.03Mpc, and for the group of galaxies around M 81/M 82, 0.89±0.05Mpc. These yield estimates of MT = (1.29±0.14)· 1012 M⊙ and (1.03±0.17)· 1012 M⊙, respectively, for the total masses of these groups. The R0 method allows us to determine the mass ratios for the two brightest members in both groups, as well. By varying the position
of the center of mass between the two principal members of a group to obtain minimal scatter in the galaxies on a Hubble diagram,
we find mass ratios of 0.8:1.0 for our galaxy and Andromeda and 0.54:1.00 for the M82 and M81 galaxies, in good agreement
with the observed ratios of the luminosities of these galaxies.
__________
Translated from Astrofizika, Vol. 49, No. 1, pp. 5–22 (February 2006). |
| |
| Keywords: | Galaxies Local group M81 group-galaxies masses |
| 本文献已被 SpringerLink 等数据库收录！ |
|
