Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-08-31
Mon.Not.Roy.Astron.Soc.327:L27,2001
Astronomy and Astrophysics
Astrophysics
5 pages, 1 figures, MNRAS (submitted)
Scientific paper
10.1046/j.1365-8711.2001.04968.x
The microlensing optical depth to Baade's Window constrains the minimum total mass in baryonic matter within the Solar circle to be greater than 3.9 x 10^{10} solar masses, assuming the inner Galaxy is barred with viewing angle of roughly 20 degrees. From the kinematics of solar neighbourhood stars, the local surface density of dark matter is about 30 +/- 15 solar masses per square parsec. We construct cuspy haloes normalised to the local dark matter density and calculate the circular-speed curve of the halo in the inner Galaxy. This is added in quadrature to the rotation curve provided by the stellar and ISM discs, together with a bar sufficiently massive so that the baryonic matter in the inner Galaxy reproduces the microlensing optical depth. Such models violate the observational constraint provided by the tangent-velocity data in the inner Galaxy (typically at radii 2-4 kpc). The high baryonic contribution required by the microlensing is consistent with implications from hydrodynamical modelling and the pattern speed of the Galactic bar. We conclude that the cuspy haloes favoured by the Cold Dark Matter cosmology (and its variants) are inconsistent with the observational data on the Galaxy.
Binney James
Evans Wyn N.
No associations
LandOfFree
Cuspy Dark-Matter Haloes and the Galaxy 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 Cuspy Dark-Matter Haloes and the Galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cuspy Dark-Matter Haloes and the Galaxy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-673266