Planetary nebulae with Wolf-Rayet-type central stars-I. the case of the high-excitation NGC 2371

We present the analysis of the planetary nebula (PN) NGC 2371 around the [Wolf-Rayet] (WR) star WD 0722+295. Our Isaac Newton Telescope intermediate dispersion spectrograph spectra, in conjunction with archival optical and ultraviolet images, unveil in unprecedented detail the high ionization of NGC...

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Detalles Bibliográficos
Autores: Gómez-González, V. M. A., Toalá, Jesús A., Guerrero, Martín A., Todt, H., Sabin, L., Ramos-Larios, G., Mayya, Y. D.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/217682
Acceso en línea:http://hdl.handle.net/10261/217682
Access Level:acceso abierto
Palabra clave:Planetary nebulae: general
Planetary nebulae: individual: NGC 2371
Stars: evolution
Stars: winds, outflows
Descripción
Sumario:We present the analysis of the planetary nebula (PN) NGC 2371 around the [Wolf-Rayet] (WR) star WD 0722+295. Our Isaac Newton Telescope intermediate dispersion spectrograph spectra, in conjunction with archival optical and ultraviolet images, unveil in unprecedented detail the high ionization of NGC 2371. The nebula has an apparent multipolar morphology, with two pairs of lobes protruding from a barrel-like central cavity, a pair of dense low ionization knots misaligned with the symmetry axis embedded within the central cavity, and a high-excitation halo mainly detected in He ii. The abundances from the barrel-like central cavity and dense knots agree with abundance determinations for other PNe with [WR]-type central stars of PNe. We suggest that the densest knots inside NGC 2371 are the oldest structures, remnant of a dense equatorial structure, while the main nebular shell and outer lobes resulted from a latter ejection that ended the stellar evolution. The analysis of position-velocity diagrams produced from our high-quality spectra suggests that NGC 2371 has a bipolar shape with each lobe presenting a double structure protruding from a barrel-like central region. The analysis of the spectra of WD 0722+295 results in similar stellar parameters as previously reported. We corroborate that the spectral subtype corresponds with a [WO1] type. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.