Detection of nonthermal emission from the bow shock of a massive runaway star

Context. The environs of massive, early-type stars have been inspected in recent years in the search for sites where particles can be accelerated up to relativistic energies. Wind regions of massive binaries that collide have already been established as sources of high-energy emission; however, ther...

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Detalles Bibliográficos
Autores: Benaglia, Paula, Romero, Gustavo Esteban, Martí, J., Peri, Cintia Soledad, Araudo, Anabella Teresa
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2010
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/82448
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/82448
Access Level:acceso abierto
Palabra clave:Ciencias Astronómicas
Infrared: stars
Radio continuum: general
Stars: early-type
Stars: individual: BD+43°3654
Infrared: star
Descripción
Sumario:Context. The environs of massive, early-type stars have been inspected in recent years in the search for sites where particles can be accelerated up to relativistic energies. Wind regions of massive binaries that collide have already been established as sources of high-energy emission; however, there is a different scenario for massive stars where strong shocks can also be produced: the bow-shaped region of matter piled up by the action of the stellar strong wind of a runaway star interacting with the interstellar medium. Aims. We study the bow-shock region produced by a very massive runaway star, BD+43°3654, to look for nonthermal radio emission as evidence of a relativistic particle population. Methods. We observed the field of BD+43°3654 at two frequencies, 1.42 and 4.86 GHz, with the Very Large Array (VLA), and obtained a spectral index map of the radio emission. Results. We have detected, for the first time, nonthermal radio emission from the bow shock of a massive runaway star. Conclusions. After analyzing the radiative mechanisms that can be at work, we conclude that the region under study could produce enough relativistic particles whose radiation might be detectable by forthcoming gamma-ray instruments, like CTA North.