Extended Hi Rotation Curve and Mass Distribution of M31
نویسنده
چکیده
New HI observations of Messier 31 (M31) obtained with the Effelsberg and Green Bank 100-m telescopes make it possible to measure the rotation curve of that galaxy out to ∼ 35 kpc. Between 20 and 35 kpc, the rotation curve is nearly flat at a velocity of ∼ 226 km s−1 . A model of the mass distribution shows that at the last observed velocity point, the minimum dark–to–luminous mass ratio is ∼ 0.5 for a total mass of 3.4×1011 M⊙ at R < 35 kpc. This can be compared to the estimated MW mass of 4.9×1011 M⊙ for R < 50 kpc. Subject headings: galaxies: halos — galaxies: fundamental parameter (mass) — galaxies: individual (M31) — galaxies: kinematics and dynamics galaxies: structure — Local Group
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تاریخ انتشار 2006