Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-12-11
Astronomy and Astrophysics
Astrophysics
Accepted for publication in MNRAS Letters. 5 pages, 2 figures
Scientific paper
10.1111/j.1745-3933.2008.00435.x
We present the analysis of 23 published rotation curves of disk galaxies belonging to the Ursa Major group of galaxies, with kinematics free of irregularities. The rotation curves are analysed in the context of MOND (Modified Newtonian Dynamics). We add an extra component to the rotation curve fits, in addition to the stellar and gaseous disks: a speculative halo of constant density made of, e.g., neutrinos, which would solve the bulk of the problem currently faced by MOND on rich galaxy clusters scales. We find that this additional unseen mass density is poorly constrained (as expected a priori, given that a neutrino halo never dominates the kinematics), but we also find that the best-fit value is non-zero: rho = 3.8 x 10^{-27} g/cm^3, and that a zero-density is marginally excluded with 87% confidence; also, the 95% confidence upper limit for the density is rho = 9.6 x 10^{-27} g/cm^3. These limits are slightly above the expectations from the Tremaine-Gunn phase space constraints on ordinary 2 eV neutrinos, but in accordance with the maximum density expected for one or two species of 5 eV sterile neutrinos.
Famaey Benoit
Gentile Gianfranco
Zhao Hai-Sheng
No associations
LandOfFree
Neutrinos as galactic dark matter in the Ursa Major galaxy group? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Neutrinos as galactic dark matter in the Ursa Major galaxy group?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Neutrinos as galactic dark matter in the Ursa Major galaxy group? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-660790