X-Ray Observations of Bow Shocks around Runaway O Stars. The Case of ζ Oph and BD+43°3654

Non-thermal radiation has been predicted within bow shocks around runaway stars by recent theoretical works. We present X-ray observations toward the runaway stars ζ Oph by Chandra and Suzaku and of BD+43°3654 by XMM-Newton to search for the presence of non-thermal X-ray emission. We found no eviden...

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Detalles Bibliográficos
Autores: Toalá, Jesús A., Oskinova, L. M., González-Galán, A., Guerrero, Martín A., Ignace, R., Pohl, Martin
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2016
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/381970
Acceso en línea:http://hdl.handle.net/10261/381970
Access Level:acceso abierto
Palabra clave:Stars: individual (ζ Oph, BD+43°3654)
Stars: winds, outflows
Descripción
Sumario:Non-thermal radiation has been predicted within bow shocks around runaway stars by recent theoretical works. We present X-ray observations toward the runaway stars ζ Oph by Chandra and Suzaku and of BD+43°3654 by XMM-Newton to search for the presence of non-thermal X-ray emission. We found no evidence of non-thermal emission spatially coincident with the bow shocks; nonetheless, diffuse emission was detected in the vicinity of ζ Oph. After a careful analysis of its spectral characteristics, we conclude that this emission has a thermal nature with a plasma temperature of T ≈ 2 × 10 K. The cometary shape of this emission seems to be in line with recent predictions of radiation-hydrodynamic models of runaway stars. The case of BD+43°3654 is puzzling, as non-thermal emission has been reported in a previous work for this source. © 2016. The American Astronomical Society. All rights reserved.