The proton low-mass microquasar: High-energy emission

Context. A population of unidentified gamma-ray sources is forming a structure resembling a halo around the Galactic center. These sources are highly variable, and hence they should be associated with compact objects. Microquasars are objects undergoing accretion with relativistic jets; if such an o...

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Detalles Bibliográficos
Autores principales: Romero, Gustavo Esteban, Vila, Gabriela Soledad
Formato: Articulo
Lenguaje:Inglés
Publicado: 2008
Materias:
Ciencias Astronómicas
Gamma rays: theory
Radiation mechanisms: non-thermal
X-rays: binaries
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84322
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-84322
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Gamma rays: theory
Radiation mechanisms: non-thermal
X-rays: binaries
spellingShingle Ciencias Astronómicas
Gamma rays: theory
Radiation mechanisms: non-thermal
X-rays: binaries
Romero, Gustavo Esteban
Vila, Gabriela Soledad
The proton low-mass microquasar: High-energy emission
topic_facet Ciencias Astronómicas
Gamma rays: theory
Radiation mechanisms: non-thermal
X-rays: binaries
description Context. A population of unidentified gamma-ray sources is forming a structure resembling a halo around the Galactic center. These sources are highly variable, and hence they should be associated with compact objects. Microquasars are objects undergoing accretion with relativistic jets; if such an object has a low-mass, evolved, donor star, it might be found in the Galactic halo. If these low-mass microquasars can generate detectable gamma-ray emission, then they are natural candidates to account for the halo high-energy sources. Aims. We aim to construct models for high-energy emission of low-mass microquasars, which could produce a significant luminosity in the gamma-ray domain. Methods. We consider that a significant fraction of the relativistic particles in the jets of low-mass microquasars are protons and then we study the production of high-energy emission through proton synchrotron radiation and photopion production. Photopair production and leptonic processes are considered as well. We compute a number of specific models with different parameters to explore the possibilities of this scenario. Results. We find that important luminosities, in the range of 10<SUP>34</SUP>-10<SUP>37</SUP> erg s<SUP>-1</SUP>, can be achieved by proton synchrotron radiation in the Gamma-Ray Large Area Space Telescope (GLAST) energy range, and lower, but still significant luminosities at higher energies for some models. Conclusions. We conclude that the proton microquasar model offers a very interesting alternative to account for the halo gamma-ray sources and presents a variety of predictions that might be tested in the near future by instruments like GLAST, the High-Energy Stereoscopic System II (HESS II), the Major Atmospheric Gamma-ray Imaging Cherenkov telescope II (MAGIC II), and neutrino telescopes like IceCube.
format Articulo
Articulo
author Romero, Gustavo Esteban
Vila, Gabriela Soledad
author_facet Romero, Gustavo Esteban
Vila, Gabriela Soledad
author_sort Romero, Gustavo Esteban
title The proton low-mass microquasar: High-energy emission
title_short The proton low-mass microquasar: High-energy emission
title_full The proton low-mass microquasar: High-energy emission
title_fullStr The proton low-mass microquasar: High-energy emission
title_full_unstemmed The proton low-mass microquasar: High-energy emission
title_sort proton low-mass microquasar: high-energy emission
publishDate 2008
url http://sedici.unlp.edu.ar/handle/10915/84322
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AT romerogustavoesteban protonlowmassmicroquasarhighenergyemission
AT vilagabrielasoledad protonlowmassmicroquasarhighenergyemission
bdutipo_str Repositorios
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