Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments (original) (raw)

$\gamma$-Rays from Dark Matter Annihilation in Milky Way Satellite Galaxies: An Analysis with Particle Dark Matter Models for 45 Dwarf Spheroidals

arXiv: Cosmology and Nongalactic Astrophysics, 2019

This has been suggested that the dwarf satellite galaxies in the Milky Way may contain substantial amount of dark matter in them. These dark matters may undergo self-annihilation to produce gamma\gammagamma-rays. The satellite borne gamma\gammagamma-rays telescope such as Fermi-LAT reported the detection of gamma\gammagamma-rays from around 45 Dwarf Spheroidals (dSphs) of Milky Way. In this work, we consider a particle dark matter model and after studying its phenomenology, we calculate the gamma\gammagamma-ray fluxes of each of these 45 dSphs and compare our results with the upper bounds of mass vs annihilation cross-sections of dark matter provided by the Fermi-LAT collaboration. We calculate these fluxes by considering different dark matter density profiles and make a comparison of the results. We also repeat our analysis with another dark matter candidate namely Kaluza-Klein dark matter inspired by extra-dimensional models. We make a critical comparison between the results obtained for each of these models vis...

Extracting limits on Dark Matter annihilation from dwarf Spheroidal galaxies at gamma-rays

2012

Dwarf spheroidal galaxies compose one of the most dark matter dominated classes of objects, making them a set of targets to search for signals of dark matter annihilation. Recent developments in gamma-ray astronomy, most importantly the launch of the Fermi-LAT instrument, have brought those targets into attention. Yet, no clear excess of gamma-rays has been confirmed from these targets, resulting in some of the tightest limits on dark matter annihilation from indirect searches. In extracting limits from dwarf spheroidal galaxies, it is of great importance, to properly take into account all relevant uncertainties. Those include the dark matter distribution properties of the dwarf spheroidals and the uncertainties on the underlying background. We revisit the limits on dark matter annihilation, from gamma-rays studying a set of close-by dwarf spheroidal galaxies, for which, we have good understanding of the uncertainties in the dark matter distribution. For those targets, we perform and compare results for alternative methods in extracting the background gamma-ray flux. This provides a method to discriminate among the dark matter annihilation targets, those that can give robust constraints. We finally present our tightest limits on dark matter annihilation, that come only from the targets that ensure accurate understanding of both the gamma-ray background and the dark matter distribution uncertainties.

Addressing γ-ray emissions from dark matter annihilations in 45 Milky Way satellite galaxies and in extragalactic sources with particle dark matter models

Monthly Notices of the Royal Astronomical Society

The mass-to-luminosity ratio of the dwarf satellite galaxies in the Milky Way suggests that these dwarf galaxies may contain substantial dark matter. The dark matter at the dense region such as within or at the vicinity of the centres of these dwarf galaxies may undergo the process of self-annihilation and produce γ-rays as the end product. The satellite borne γ-ray telescope such as Fermi-LAT reported the detection of γ-rays from around 45 Dwarf Spheroidals (dSphs) of Milky Way. In this work, we consider particle dark matter models described in the literature and after studying their phenomenologies, we calculate the γ-ray fluxes from the self-annihilation of the dark matter within the framework of these models in case of each of these 45 dSphs. We then compare the computed results with the observational upper bounds for γ-ray flux reported by Fermi-LAT and Dark Energy Survey for each of the 45 dSphs. The fluxes are calculated by adopting different dark matter density profiles. We ...

Observations of Milky Way Dwarf Spheroidal galaxies with the Fermi-LAT detector and constraints on Dark Matter models

2018

We report on the observations of 14 dwarf spheroidal galaxie s with theFermi Gamma-Ray Space Telescope taken during the first 11 months of survey mod e operations. TheFermi telescope, which is conducting an all-sky γ-ray survey in the 20 MeV to>300 GeV energy range, provides a new opportunity to test particle dark matter mode ls through the expected γ-ray emission produced by pair annihilation of weakly interacting ma ssive particles (WIMPs). Local Group dwarf spheroidal galaxies, the largest galactic subs tr ctures predicted by the cold dark 31University of Alabama in Huntsville, Huntsville, AL 35899, USA 32Department of Physics, Center for Cosmology and Astro-Part icle Physics, The Ohio State University, Columbus, OH 43210 , USA 33Department of Physics, Royal Institute of Technology (KTH) , AlbaNova, SE-106 91 Stockholm, Sweden 34UCO/Lick Observatories, Santa Cruz, CA 95064, USA 35Department of Physics, Tokyo Institute of Technology, Megu ro City, Tokyo 152-8551, Japan 36Waseda...