Can the dark matter annihilation signal be significantly boosted by substructures?
arXiv:1506.08609 · doi:10.1088/1475-7516/2016/01/018
Abstract
A very general cosmological consideration suggests that, along with galactic dark matter halos, much smaller dark matter structures may exist. These structures are usually called 'clumps', and their mass extends to or even lower. The clumps should give the main contribution into the signal of dark matter annihilation, provided that they have survived until the present time. Recent observations favor a cored profile for low-mass astrophysical halos. We consider cored clumps and show that they are significantly less firm than the standard NFW ones. In contrast to the standard scenario, the cored clumps should have been completely destroyed inside ~{kpc} from the Milky Way center. The dwarf spheroidals should not contain any dark matter clumps. On the other hand, even under the most pessimistic assumption about the clump structure, the clumps should have survived in the Milky Way at a distance exceeding ~{kpc} from the center, as well as in low-density cosmic structures. There they significantly boost the dark matter annihilation. We show that at least of the clumps endured the primordial structure formation should still exist untouched in the present-day Universe.
10 pages, 4 figures, accepted to JCAP
References in corpus (8)
- Segue 1: An Unevolved Fossil Galaxy from the Early Universe
- The flattening of the concentration-mass relation towards low halo masses and its implications for the annihilation signal boost
- NGC 3741: dark halo profile from the most extended rotation curve
- A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
- The Collision Between The Milky Way And Andromeda
- Remnants of dark matter clumps
- Indirect Dark Matter Detection Limits from the Ultra-Faint Milky Way Satellite Segue 1
- The real and apparent convergence of N-body simulations of the dark matter structures: is the Navarro-Frenk-White profile real?