ACP Seminar (Astronomy - Cosmology - Particle Physics)

Speaker: Marco Valdes (Pisa)
Title: The high-z interplay between annihilating DM and the IGM
Date (JST): Thu, Jun 16, 2011, 13:30 - 15:00
Place: Seminar Room A
Related File: 463.pdf
Abstract: We study the interactions of some of the most popular annihilating/decaying Dark Matter (DM) candidates with the Inter-Galactic Medium (IGM) during the so called Dark Ages of the Universe, i.e. during the extended epoch between Cosmic Recombination and Reionization at redshift z ≈ 1100, z ≈ 10 respectively. DM decays/annihilations will modify the thermal and ionization history of the IGM, possibly leaving an observable trace on a number of observable frequencies such as (i) the radio HI 21 cm line; (ii) X and gamma rays; (iii) microwave by modifications to the CMB power spectrum.
To achieve our goals we use the self-developed Monte Carlo scheme MEDEA2 to study the secondary energy cascade from fast electrons, positrons and photons (the main products of DM decays/annihilations) injected into a partially ionized gas. MEDEA2 represents a powerful tool for a very large number of astrophysical investigations and especially for DM studies, giving us the chance to precisely predict the observable traces left by any DM candidate. Our predictions will help constrain the elusive nature of DM as new sets of observations become available in the next few years.