Absence of hot gas within the Wolf-Rayet bubble around WR¿16

We present the analysis of XMM-Newton archival observations towards the Wolf-Rayet (WR) bubble around WR16. Despite the closed bubble morphology of this WR nebula, the XMM-Newton observations show no evidence of diffuse emission in its interior as in the similar WR bubbles NGC6888 and S 308. We use...

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Detalles Bibliográficos
Autores: Toalá, Jesús A., Guerrero, Martín A.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/408721
Acceso en línea:http://hdl.handle.net/10261/408721
Access Level:acceso abierto
Palabra clave:Circumstellar matter
ISM: bubbles
Pulsars: individual: WR16
Stars: massive
Stars: Wolf-Rayet
Descripción
Sumario:We present the analysis of XMM-Newton archival observations towards the Wolf-Rayet (WR) bubble around WR16. Despite the closed bubble morphology of this WR nebula, the XMM-Newton observations show no evidence of diffuse emission in its interior as in the similar WR bubbles NGC6888 and S 308. We use the present observations to estimate a 3-σ upper limit to the X-ray luminosity in the 0.3 - 1.5 keV energy band equal to 7.4× 1032 erg s-1 for the diffuse emission from the WR nebula, assuming a distance of 2.37 kpc. TheWR nebula around WR16 is the fourth observed by the current generation of X-ray satellites and the second not detected. We also examine FUSE spectra to search for nebular O vi absorption lines in the stellar continuum of WR16. The present far-UV data and the lack of measurements of the dynamics of the optical WR bubble do not allow us to confirm the existence of a conductive layer of gas at T ~ 3× 105 K between the cold nebular gas and the hot gas in its interior. The present observations result in an upper limit of n e < 0.6 cm-3 on the electron density of the X-ray emitting material within the nebula. © ESO 2013.