EXPLORING A THERMAL MODEL FOR THE TIME VARIABILITY OF THE RADIO EMISSION FROM THE CEN 1a SYSTEM

In this work we explore the possibility that the observed time variable emission at radio frequencies from the CEN 1a system has a thermal origin. The observed flux densities and spectral indices from this source clearly deviate from the standard stellar wind model around a massive star, and seem to...

Descripción completa

Detalles Bibliográficos
Autores: R. F. González, L. F. Rodríguez, J. Cantó
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:México
Institución:Universidad Nacional Autónoma de México
Repositorio:Redalyc-UNAM
OAI Identifier:oai:redalyc.org:57126152004
Acceso en línea:https://www.redalyc.org/articulo.oa?id=57126152004
Access Level:acceso abierto
Palabra clave:Física, Astronomía y Matemáticas
radio
shock waves
continuum: ISM
Descripción
Sumario:In this work we explore the possibility that the observed time variable emission at radio frequencies from the CEN 1a system has a thermal origin. The observed flux densities and spectral indices from this source clearly deviate from the standard stellar wind model around a massive star, and seem to be consistent with opticallythin thermal emission. Here we investigate the radio-continuum free-free emission from a stellar wind with time-dependent injection parameters, which result in the formation of internal shocks that travel away from the central star. Although our model is able to predict the observed flux densities and spectral indices from the CEN 1a source, it fails to explain the detected variability in the optically-thin regime. We conclude that the observed emission has a composite nature, with thermal and non-thermal contributions.