Lepto-hadronic model for the broadband emission of Cygnus X-1

Context. Cygnus X-1 is a well-observed microquasar. Broadband observations at all wavelengths have been collected over the years. The origin of the MeV tail observed with COMPTEL and INTEGRAL is still under debate and it has mostly been attributed to the corona, although its high degree of polarizat...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Pepe, Carolina, Vila, Gabriela Soledad, Romero, Gustavo Esteban
Formato: Articulo
Lenguaje:Inglés
Publicado: 2015
Materias:
Ciencias Astronómicas
Gamma rays: general
Radiation mechanisms: non-thermal
X-rays: binaries
X-rays: individuals: Cygnus X-1
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/86334
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-86334
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: general
Radiation mechanisms: non-thermal
X-rays: binaries
X-rays: individuals: Cygnus X-1
spellingShingle Ciencias Astronómicas
Gamma rays: general
Radiation mechanisms: non-thermal
X-rays: binaries
X-rays: individuals: Cygnus X-1
Pepe, Carolina
Vila, Gabriela Soledad
Romero, Gustavo Esteban
Lepto-hadronic model for the broadband emission of Cygnus X-1
topic_facet Ciencias Astronómicas
Gamma rays: general
Radiation mechanisms: non-thermal
X-rays: binaries
X-rays: individuals: Cygnus X-1
description Context. Cygnus X-1 is a well-observed microquasar. Broadband observations at all wavelengths have been collected over the years. The origin of the MeV tail observed with COMPTEL and INTEGRAL is still under debate and it has mostly been attributed to the corona, although its high degree of polarization suggests that it is synchrotron radiation from a jet. The origin of the transient emission above ~100 GeV is also unclear. Aims. We aim to clarify the origin of the broadband spectral energy distribution (SED) of Cygnus X-1, focusing particularly on the gamma-ray emission, and to gain information on the physical conditions inside the jets. Methods. We developed a lepto-hadronic, inhomogeneous jet model and applied it to the non-thermal SED of Cygnus X-1. We calculated the contributions to the SED of both protons and electrons accelerated in an extended region of the jet. We also estimated the radiation of charged secondaries produced in hadronic interactions through several radiative processes. Absorption effects were considered. We produced synthetic maps of the jets at radio wavelengths. Results. We find two sets of model parameters that lead to good fits of the SED. One of the models fits all the observations, including the MeV tail. This model also predicts hadronic gamma-ray emission slightly below the current upper limits. The flux predicted at 8.4 GHz is in agreement with the observations available in the literature, although the synthetic source is more compact than the imaged radio jet. Conclusions. Our results show that the MeV emission in Cygnus X-1 may be jet synchrotron radiation. This depends mainly on the strength of the jet magnetic field and the location of the injection region of the relativistic particles. Our calculations show that there must be energetic electrons in the jets quite far from the black hole.
format Articulo
Articulo
author Pepe, Carolina
Vila, Gabriela Soledad
Romero, Gustavo Esteban
author_facet Pepe, Carolina
Vila, Gabriela Soledad
Romero, Gustavo Esteban
author_sort Pepe, Carolina
title Lepto-hadronic model for the broadband emission of Cygnus X-1
title_short Lepto-hadronic model for the broadband emission of Cygnus X-1
title_full Lepto-hadronic model for the broadband emission of Cygnus X-1
title_fullStr Lepto-hadronic model for the broadband emission of Cygnus X-1
title_full_unstemmed Lepto-hadronic model for the broadband emission of Cygnus X-1
title_sort lepto-hadronic model for the broadband emission of cygnus x-1
publishDate 2015
url http://sedici.unlp.edu.ar/handle/10915/86334
work_keys_str_mv AT pepecarolina leptohadronicmodelforthebroadbandemissionofcygnusx1
AT vilagabrielasoledad leptohadronicmodelforthebroadbandemissionofcygnusx1
AT romerogustavoesteban leptohadronicmodelforthebroadbandemissionofcygnusx1
bdutipo_str Repositorios
_version_ 1764820489582149632

Ejemplares similares