Pressure from dark matter annihilation and the rotation curve of spiral galaxies
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2011 RAS ©2011 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
| Authors: | ; |
|---|---|
| Format: | Article |
| Publication date: | 2011 |
| Country: | España |
| Institution: | Universidad Autónoma de Madrid |
| Repository: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Language: | English |
| OAI Identifier: | oai:repositorio.uam.es:10486/666939 |
| Online Access: | http://hdl.handle.net/10486/666939 https://dx.doi.org/10.1111/j.1365-2966.2011.18275.x |
| Access Level: | Open access |
| Keyword: | Astroparticle physics Dark matter Galaxies: haloes Galaxies: kinematics and dynamics Física |
| _version_ | 1878731857270407168 |
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| author | Wechakama, M. |
| author2 | Ascasibar Sequeiros, Yago |
| author2_role | author |
| author_browse | Ascasibar Sequeiros, Yago Wechakama, M. |
| author_facet | Wechakama, M. Ascasibar Sequeiros, Yago |
| author_role | author |
| collection | Biblos-e Archivo. Repositorio Institucional de la UAM |
| description | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2011 RAS ©2011 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
| eu_rights_str_mv | openAccess |
| format | article |
| id | ES_37f9b68ddf265cfbfbbcb2f1c376f2fe |
| institution | Universidad Autónoma de Madrid |
| instname_str | Universidad Autónoma de Madrid |
| language | eng |
| network_acronym_str | ES |
| network_name_str | España |
| oai_identifier_str | oai:repositorio.uam.es:10486/666939 |
| publishDate | 2011 |
| publishDateSort | 2011 |
| publisher | Royal Astronomical Society Oxford University Press |
| publisherStr | Oxford University Press Royal Astronomical Society |
| reponame_str | Biblos-e Archivo. Repositorio Institucional de la UAM |
| spelling | Pressure from dark matter annihilation and the rotation curve of spiral galaxies Wechakama, M. Ascasibar Sequeiros, Yago Astroparticle physics Dark matter Galaxies: haloes Galaxies: kinematics and dynamics Física This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2011 RAS ©2011 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. The rotation curves of spiral galaxies are one of the basic predictions of the cold dark matter paradigm, and their shape in the innermost regions has been hotly debated over the last decades. The present work shows that dark matter annihilation into electron-positron pairs may affect the observed rotation curve by a significant amount. We adopt a model-independent approach, where all the electrons and positrons are injected with the same initial energy E0~mdmc2 in the range from 1 MeV to 1 TeV and the injection rate is constrained by INTEGRAL, Fermi and HESS data. The pressure of the relativistic electron-positron gas is determined by solving the diffusion-loss equation, considering inverse Compton scattering, synchrotron radiation, Coulomb collisions, bremsstrahlung and ionization. For values of the gas density and magnetic field that are representative of the Milky Way, it is estimated that pressure gradients are strong enough to balance gravity in the central parts if E0 < 1GeV. The exact value depends somewhat on the astrophysical parameters, and it changes dramatically with the slope of the dark matter density profile. For very steep slopes, as those expected from adiabatic contraction, the rotation curves of spiral galaxies would be affected on ~kpc scales for most values of E0. By comparing the predicted rotation curves with observations of dwarf and low surface brightness galaxies, we show that the pressure from dark matter annihilation may improve the agreement between theory and observations in some cases, but it also imposes severe constraints on the model parameters (most notably, the inner slope of halo density profile, as well as the mass and the annihilation cross-section of dark matter particles into electron-positron pairs) This work has been funded by DFG Research Grant AS 312/1-1 (Germany).YA also acknowledges support from project AYA 2007-67965-C03-03 (MEC, Spain) Royal Astronomical Society Oxford University Press http://hdl.handle.net/10486/666939 https://dx.doi.org/10.1111/j.1365-2966.2011.18275.x |
| spellingShingle | Pressure from dark matter annihilation and the rotation curve of spiral galaxies Wechakama, M. Astroparticle physics Dark matter Galaxies: haloes Galaxies: kinematics and dynamics Física |
| title | Pressure from dark matter annihilation and the rotation curve of spiral galaxies |
| title_full | Pressure from dark matter annihilation and the rotation curve of spiral galaxies |
| title_fullStr | Pressure from dark matter annihilation and the rotation curve of spiral galaxies |
| title_full_unstemmed | Pressure from dark matter annihilation and the rotation curve of spiral galaxies |
| title_short | Pressure from dark matter annihilation and the rotation curve of spiral galaxies |
| title_sort | Pressure from dark matter annihilation and the rotation curve of spiral galaxies |
| topic | Astroparticle physics Dark matter Galaxies: haloes Galaxies: kinematics and dynamics Física |
| topic_facet | Astroparticle physics Dark matter Galaxies: haloes Galaxies: kinematics and dynamics Física |
| url | http://hdl.handle.net/10486/666939 https://dx.doi.org/10.1111/j.1365-2966.2011.18275.x |