A very large array 3.6 centimeter continuum survey of galactic wolf-rayet stars

We report the results of a survey of radio continuum emission of Galactic Wolf-Rayet (WR) stars north of δ = -46°. The observations were obtained at 8.46 GHz (3.6 cm) using the Very Large Array, with an angular resolution of ∼6″ × 9″ and typical rms noise of ∼0.04 mJy beam<SUP>-1</SUP>....

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Autores principales: Cappa, Cristina Elisabet, Goss, W. M., Hucht, K. A. van der
Formato: Articulo
Lenguaje:Inglés
Publicado: 2004
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83534
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id I19-R120-10915-83534
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Radio continuum: stars
Stars: mass loss
Stars: Wolf-Rayet
spellingShingle Ciencias Astronómicas
Radio continuum: stars
Stars: mass loss
Stars: Wolf-Rayet
Cappa, Cristina Elisabet
Goss, W. M.
Hucht, K. A. van der
A very large array 3.6 centimeter continuum survey of galactic wolf-rayet stars
topic_facet Ciencias Astronómicas
Radio continuum: stars
Stars: mass loss
Stars: Wolf-Rayet
description We report the results of a survey of radio continuum emission of Galactic Wolf-Rayet (WR) stars north of δ = -46°. The observations were obtained at 8.46 GHz (3.6 cm) using the Very Large Array, with an angular resolution of ∼6″ × 9″ and typical rms noise of ∼0.04 mJy beam<SUP>-1</SUP>. Our survey of 34 WR stars resulted in 15 definite, and five probable detections, 13 of these for the first time at radio wavelengths. All detections are unresolved (θ ≲ 5″). Time variations in flux are confirmed in the cases of WR 98a, 104, 105, and 125. WR 79a and WR 89 are also variable in flux, and we suspect they are also nonthermal emitters. Thus, of our sample 20%30% of the detected stars are nonthermal emitters. Average mass-loss rate determinations obtained excluding definite and suspected nonthermal cases give similar values for WN (all subtypes) and WC5-7 stars [M(WN) = (4 ± 3) × 10<SUP>-5</SUP> M⊙ yr<SUP>-1</SUP> and M(WC5-7) = (4 ± 2) × 10<SUP>-5</SUP> M⊙ yr<SUP>-1</SUP>], while a lower value was obtained for WC8-9 stars [M(WC8-9) = (2 ± 1) × 10<SUP>-5</SUP> M ⊙ yr<SUP>-1</SUP>]. Uncertainties in stellar distances largely contribute to the observed scatter in mass-loss rates. Upper limits to the mass-loss rates were obtained in cases of undetected sources and for sources that probably show additional nonthermal emission.
format Articulo
Articulo
author Cappa, Cristina Elisabet
Goss, W. M.
Hucht, K. A. van der
author_facet Cappa, Cristina Elisabet
Goss, W. M.
Hucht, K. A. van der
author_sort Cappa, Cristina Elisabet
title A very large array 3.6 centimeter continuum survey of galactic wolf-rayet stars
title_short A very large array 3.6 centimeter continuum survey of galactic wolf-rayet stars
title_full A very large array 3.6 centimeter continuum survey of galactic wolf-rayet stars
title_fullStr A very large array 3.6 centimeter continuum survey of galactic wolf-rayet stars
title_full_unstemmed A very large array 3.6 centimeter continuum survey of galactic wolf-rayet stars
title_sort very large array 3.6 centimeter continuum survey of galactic wolf-rayet stars
publishDate 2004
url http://sedici.unlp.edu.ar/handle/10915/83534
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