WISE morphological study of Wolf-Rayet nebulae

We present a morphological study of nebulae around Wolf-Rayet (WR) stars using archival narrow-band optical and Wide-field Infrared Survey Explorer (WISE) infrared images. The comparison among WISE images in different bands and optical images proves to be a very efficient procedure to identify the n...

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Detalles Bibliográficos
Autores: Toalá, Jesús A., Guerrero, Martín A., Ramos-Larios, G., Guzmán, V.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/388536
Acceso en línea:http://hdl.handle.net/10261/388536
Access Level:acceso abierto
Palabra clave:Stars: massive
Stars: Wolf-Rayet
Stars: winds, outflows
ISM: bubbles
Descripción
Sumario:We present a morphological study of nebulae around Wolf-Rayet (WR) stars using archival narrow-band optical and Wide-field Infrared Survey Explorer (WISE) infrared images. The comparison among WISE images in different bands and optical images proves to be a very efficient procedure to identify the nebular emission from WR nebulae, and to disentangle it from that of the ISM material along the line of sight. In particular, WR nebulae are clearly detected in the WISE W4 band at 22 μm. Analysis of available mid-IR Spitzer spectra shows that the emission in this band is dominated by thermal emission from dust spatially coincident with the thin nebular shell or most likely with the leading edge of the nebula. The WR nebulae in our sample present different morphologies that we classified into well defined WR bubbles (bubble -type nebulae), clumpy and/or disrupted shells (clumpy/disrupted \hbox{${\cal C}$}-type nebulae), and material mixed with the diffuse medium (mixed -type nebulae). The variety of morphologies presented by WR nebulae shows a loose correlation with the central star spectral type, implying that the nebular and stellar evolutions are not simple and may proceed according to different sequences and time-lapses. We report the discovery of an obscured shell around WR 35 only detected in the infrared. © ESO, 2015.