Stefano Profumo, Lorenzo Ubaldi, Mikhail Gorchtein
Active Galactic Nuclei (AGN) host powerful jets containing high-energy electrons and protons. The astrophysical environment where AGNs and their jets are found is characterized by large concentrations of both dark matter (DM) and intra-cluster medium (ICM) gas. As the high-energy jet particles transverse the DM and the ICM, elastic and inelastic scattering processes generically lead to the production of final-state photons. As first envisioned by Bloom and Wells (1998), and as more recently pointed out by us and others, the scattering of electrons off of DM could lead to a potentially detectable gamma-ray signal, with the parton-level contribution from protons offering dimmer perspectives. Recently, Chang et al. argued that taking into account photons from hadronization and showering of the proton remnants, the actual photon flux is dramatically increased, as long as a fraction of the jet protons are aligned with our line of sight. Here, we point out that those jet protons would generically produce a very large flux of photons from inelastic collisions with ICM nucleons, which would outshine by many orders of magnitude the signal from DM, for almost any reasonable ICM and DM density profiles.
View original:
http://arxiv.org/abs/1302.1915
No comments:
Post a Comment