Thursday, June 10th, 2004
15.30 h.
Módulo C-XI, 2nd floor, room 201

Francisco Prada
Instituto de Astrofisica de Andalucia, CSIC.
Expectations and Desperations of Dark Matter in Galaxies

Abstract:

If the dark matter, which is considered to constitute most of the mass of
galaxies, is made of supersymmetric particles, the center of galaxies should
emit gamma-rays produced by their self-annihilation. I will present accurate
estimates of continuum gamma-ray fluxes due to neutralino  annihilation in
the central regions of the Milky Way. We use detailed models of our Galaxy,
which satisfy all the available observational data, and include some important
physical processes, which were previously neglected: the compression of the
dark matter due to the infall of baryons to the galactic center. Our models
predict that the gamma-ray signal coming from the annihilation products of
the SUSY dark matter should be detected at high confidence levels by incoming
experiments in the next 2-3 years. I will also discuss our recent results
on the mass distribution of galaxies at large radii using the Sloan Digital
Sky Survey. We find that the velocity dispersion of satellites of galaxies
declines with distance to the host galaxy. This decline agrees remarkably
well with the distribution of dark matter predicted by the cosmological
models in the peripheral parts of galaxies and contradicts the isothermal
MOND.