Abstract
In a cold dark matter (CDM) framework of structure formation, the dark matter haloes around galaxies assemble through successive mergers with smaller haloes. This merging process is not completely efficient, and hundreds of surviving halo cores, or subhaloes, are expected to remain in orbit within the halo of a galaxy like the Milky Way. While the dozen visible satellites of the Milky Way may trace some of these subhaloes, the majority are currently undetected. A large number of high-velocity clouds (HVCs) of neutral hydrogen are observed around the Milky Way, and it is plausible that some of the HVCs may trace subhaloes undetected in the optical. Confirming the existence of concentrations of dark matter associated with even a few of the HVCs would represent a dramatic step forward in our attempts to understand the nature of dark matter. Supersymmetric (SUSY) extensions of the Standard Model of particle physics currently suggest neutralinos as a natural well-motivated candidate for the non-baryonic dark matter of the universe. If this is indeed the case, then it may be possible to detect dark matter indirectly as it annihilates into neutrinos, photons or positrons. In particular, the centres of subhaloes might show up as point sources in gamma-ray observations. In this work, we consider the possibility that some of the unidentified EGRET γ-ray sources trace annihilating neutralino dark matter in the dark substructure of the Local Group. We compare the observed positions and fluxes of both the unidentified EGRET sources and the HVCs with the positions and fluxes predicted by a model of halo substructure, to determine up to what extent any of these three populations could be associated.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Benaglia, P. et al.: 2001, A&A 366, 605.
Bergstrom, L. et al.: 2001, Phys. Rev. Lett. 87, 251301.
Blitz, L. et al.: 1999, ApJ 514, 818.
Braun, R. and Burton, W.B.: 1999, A&A 341, 437.
de Heij, V., Braun, R. and Burton, W.B.: 2002, A&A 391, 159.
de Heij, V., Braun, R. and Burton, W.B.: 2002, A&A 392, 417.
Gehrels, N. et al.: 2000, Nature 404, 363.
Goldoni, P. and Musso, C.: 1996, A&AS 120, 103.
Gondolo, P. et al.: 2004, JCAP 407, 8.
Hartman, R.C. et al.: 1999, ApJS 123, 79.
Hobbs, G. et al.: 2004, MNRAS 352, 1439.
Klypin, A. et al.: 1999, ApJ 522, 82.
Martin, N.F. et al.: 2004, MNRAS 348, 12.
Mateo, M.L.: 1998, Annu. Rev. A&A 36, 435.
Moore, B. et al.: 1998, ApJL 499, L5.
Moore, B. et al.: 1999, ApJL 524, L19.
Navarro, J.F. et al.: 2004, ApJ 490, 493.
Nolan, P.L. et al.: 2003, ApJ 597, 615.
Paredes, J.M.: 2002, Mem. Soc. Astron. Ital. 73, 900.
Prada, F. et al.: 2004, Phys. Rev. Lett. 93, 241301.
Putman, M. and Moore, B.: 2001, ASP Conf. Proc. 273, 195.
Putman, M. et al.: 2002, ApJ 123, 873.
Robishaw, T., Simon, J.D. and Blitz, L. 2002, ApJ 580, 129.
Romero, G.E. et al.: 1999, A&A 348, 868.
Sowards-Emmerd, D. et al.: 2003, ApJ 590, 109.
Spergel, D.N. et al.: 2003, ApJS 148, 175.
Taylor, J.E. et al.: 2003, in: Proceedings of International Astronomical Union on Dark Matter in Galaxies, Symposium No. 220, 22–25 July, 2003, Sydney, Australia.
Torres, D.F., Romero, G.E., Dame, T.M., Combi, J.A. and Butt, Y.M.: 2003, Phys. Rep. 382, 303.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2005 Springer
About this chapter
Cite this chapter
Flix, J., Taylor, J., Martínez, M., Prada, F., Silk, J., Cortina, J. (2005). Do the Unidentified EGRET Sources Trace Annihilating Dark Matter in the Local Group?. In: Cheng, K., Romero, G. (eds) Multiwavelength Approach to Unidentified Gamma-Ray Sources. Springer, Dordrecht. https://doi.org/10.1007/1-4020-3881-X_30
Download citation
DOI: https://doi.org/10.1007/1-4020-3881-X_30
Received:
Accepted:
Publisher Name: Springer, Dordrecht
Print ISBN: 978-1-4020-3214-1
Online ISBN: 978-1-4020-3881-5
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)