| dc.creator | Romero, Gustavo Esteban | |
| dc.creator | Valle, María Victoria del | |
| dc.creator | Orellana, Mariana Dominga | |
| dc.date | 2010 | |
| dc.date | 2019-10-02T17:37:31Z | |
| dc.identifier | http://sedici.unlp.edu.ar/handle/10915/82537 | |
| dc.identifier | issn:0004-6361 | |
| dc.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. | |
| dc.description | Facultad de Ciencias Astronómicas y Geofísicas | |
| dc.format | application/pdf | |
| dc.language | en | |
| dc.rights | http://creativecommons.org/licenses/by-nc-sa/4.0/ | |
| dc.rights | Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) | |
| dc.subject | Ciencias Astronómicas | |
| dc.subject | Radiation mechanisms: non-thermal | |
| dc.subject | Stars: winds, outflows | |
| dc.subject | X-rays: binaries | |
| dc.subject | Gamma-rays: general | |
| dc.title | Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1 | |
| dc.type | Articulo | |
| dc.type | Articulo | |
