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Title: Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments

Abstract

We examine the prospects for detecting {gamma}-rays from dark matter annihilation in the six most promising dwarf spheroidal (dSph) satellite galaxies of the Milky Way. We use recently measured velocity dispersion profiles to provide a systematic investigation of the dark matter mass distribution of each galaxy, and show that the uncertainty in the {gamma}-ray flux from mass modeling is less than a factor of {approx}5 for each dSph if we assume a smooth Navarro-Frenk-White (NFW) profile. We show that Ursa Minor and Draco are the most promising dSphs for {gamma}-ray detection with GLAST and other planned observatories. For each dSph, we investigate the flux enhancement resulting from halo substructure, and show that the enhancement factor relative to a smooth halo flux cannot be greater than about 100. This enhancement depends very weakly on the lower mass cutoff scale of the substructure mass function. While the amplitude of the expected flux from each dSph depends sensitively on the dark matter model, we show that the flux ratios between the six Sphs are known to within a factor of about 10. The flux ratios are also relatively insensitive to the current theoretical range of cold dark matter halo central slopes and substructuremore » fractions.« less

Authors:
; ;  [1];  [2]
  1. Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States)
  2. Theoretical Division and ISR Division, MS B227, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Publication Date:
OSTI Identifier:
21020368
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevD.75.083526; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; ANNIHILATION; COSMIC PHOTONS; COSMOLOGY; GAMMA DETECTION; GAMMA RADIATION; MASS; MASS DISTRIBUTION; MILKY WAY; NONLUMINOUS MATTER

Citation Formats

Strigari, Louis E., Bullock, James S., Kaplinghat, Manoj, and Koushiappas, Savvas M.. Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.083526.
Strigari, Louis E., Bullock, James S., Kaplinghat, Manoj, & Koushiappas, Savvas M.. Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments. United States. doi:10.1103/PHYSREVD.75.083526.
Strigari, Louis E., Bullock, James S., Kaplinghat, Manoj, and Koushiappas, Savvas M.. Sun . "Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments". United States. doi:10.1103/PHYSREVD.75.083526.
@article{osti_21020368,
title = {Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments},
author = {Strigari, Louis E. and Bullock, James S. and Kaplinghat, Manoj and Koushiappas, Savvas M.},
abstractNote = {We examine the prospects for detecting {gamma}-rays from dark matter annihilation in the six most promising dwarf spheroidal (dSph) satellite galaxies of the Milky Way. We use recently measured velocity dispersion profiles to provide a systematic investigation of the dark matter mass distribution of each galaxy, and show that the uncertainty in the {gamma}-ray flux from mass modeling is less than a factor of {approx}5 for each dSph if we assume a smooth Navarro-Frenk-White (NFW) profile. We show that Ursa Minor and Draco are the most promising dSphs for {gamma}-ray detection with GLAST and other planned observatories. For each dSph, we investigate the flux enhancement resulting from halo substructure, and show that the enhancement factor relative to a smooth halo flux cannot be greater than about 100. This enhancement depends very weakly on the lower mass cutoff scale of the substructure mass function. While the amplitude of the expected flux from each dSph depends sensitively on the dark matter model, we show that the flux ratios between the six Sphs are known to within a factor of about 10. The flux ratios are also relatively insensitive to the current theoretical range of cold dark matter halo central slopes and substructure fractions.},
doi = {10.1103/PHYSREVD.75.083526},
journal = {Physical Review. D, Particles Fields},
number = 8,
volume = 75,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}