Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1
Context. The high-mass microquasar Cyg X-1, the best-established candidate for a stellar-mass black hole in the Galaxy, has been detected in a flaring state at very high energies (VHE), E > 200 GeV, by the Atmospheric Cherenkov Telescope MAGIC. The flare occurred at orbital phase φ = 0.91, where...
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| Formato: | Articulo |
| Lenguaje: | Inglés |
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2010
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| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/82537 |
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I19-R120-10915-82537 |
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dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
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SEDICI (UNLP) |
| language |
Inglés |
| topic |
Ciencias Astronómicas Radiation mechanisms: non-thermal Stars: winds, outflows X-rays: binaries Gamma-rays: general |
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Ciencias Astronómicas Radiation mechanisms: non-thermal Stars: winds, outflows X-rays: binaries Gamma-rays: general Romero, Gustavo Esteban Valle, María Victoria del Orellana, Mariana Dominga Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1 |
| topic_facet |
Ciencias Astronómicas Radiation mechanisms: non-thermal Stars: winds, outflows X-rays: binaries Gamma-rays: general |
| description |
Context. The high-mass microquasar Cyg X-1, the best-established candidate for a stellar-mass black hole in the Galaxy, has been detected in a flaring state at very high energies (VHE), E > 200 GeV, by the Atmospheric Cherenkov Telescope MAGIC. The flare occurred at orbital phase φ = 0.91, where φ = 1 is the configuration with the black hole behind the companion high-mass star, when the absorption of gamma-ray photons by photon-photon annihilation with the stellar field is expected to be highest. Aims. We aim to set up a model for the high-energy emission and absorption in Cyg X-1 that can explain the nature of the observed gamma-ray flare. Methods. We study the gamma-ray opacity due to pair creation along the whole orbit, and for different locations of the emitter. Then we consider a possible mechanism for the production of the VHE emission. Results. We present detailed calculations of the gamma-ray opacity and infer from these calculations the distance from the black hole where the emitting region was located. We suggest that the flare was the result of a jet-clump interaction where the decay products of inelastic p - p collisions dominate the VHE outcome. Conclusions. We are able to reproduce the spectrum of Cyg X-1 during the observed flare under reasonable assumptions. The flare may be the first event of jet-cloud interaction ever detected at such high energies. |
| format |
Articulo Articulo |
| author |
Romero, Gustavo Esteban Valle, María Victoria del Orellana, Mariana Dominga |
| author_facet |
Romero, Gustavo Esteban Valle, María Victoria del Orellana, Mariana Dominga |
| author_sort |
Romero, Gustavo Esteban |
| title |
Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1 |
| title_short |
Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1 |
| title_full |
Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1 |
| title_fullStr |
Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1 |
| title_full_unstemmed |
Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1 |
| title_sort |
gamma-ray absorption and the origin of the gamma-ray flare in cygnus x-1 |
| publishDate |
2010 |
| url |
http://sedici.unlp.edu.ar/handle/10915/82537 |
| work_keys_str_mv |
AT romerogustavoesteban gammarayabsorptionandtheoriginofthegammarayflareincygnusx1 AT vallemariavictoriadel gammarayabsorptionandtheoriginofthegammarayflareincygnusx1 AT orellanamarianadominga gammarayabsorptionandtheoriginofthegammarayflareincygnusx1 |
| bdutipo_str |
Repositorios |
| _version_ |
1764820488381530113 |