| Téléchargement | - Voir la version finale : First detection of radio emission associated with a classical Cepheid (PDF, 1.2 Mio)
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| DOI | Trouver le DOI : https://doi.org/10.3847/1538-3881/acb0c7 |
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| Auteur | Rechercher : Matthews, L. D.Identifiant ORCID : https://orcid.org/0000-0002-3728-8082; Rechercher : Evans, N. R.Identifiant ORCID : https://orcid.org/0000-0002-4374-075X; Rechercher : Rupen, M. P.1 |
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| Affiliation | - Conseil national de recherches du Canada. Herzberg en astronomie et en astrophysique
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| Bailleur de fonds | Rechercher : National Science Foundation; Rechercher : Chandra X-ray Center |
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| Format | Texte, Article |
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| Sujet | Cepheid variable stars; stellar mass loss; radio continuum emission; stellar atmospheres; stellar pulsations |
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| Résumé | We report the detection of 15 GHz radio continuum emission associated with the classical Cepheid variable star δ Cephei (δ Cep) based on observations with the Karl G. Jansky Very Large Array. Our results constitute the first probable detection of radio continuum emission from a classical Cepheid. We observed the star at pulsation phase ϕ ≈ 0.43 (corresponding to the phase of maximum radius and minimum temperature) during three pulsation cycles in late 2018 and detected statistically significant emission (>5σ) during one of the three epochs. The observed radio emission appears to be variable at a ≳10% level on timescales of days to weeks. We also present an upper limit on the 10 GHz flux density at pulsation phase ϕ = 0.31 from an observation in 2014. We discuss possible mechanisms that may produce the observed 15 GHz emission, but cannot make a conclusive identification from the present data. The emission does not appear to be consistent with originating from a close-in, late-type dwarf companion, although this scenario cannot yet be strictly excluded. Previous X-ray observations have shown that δ Cep undergoes periodic increases in X-ray flux during pulsation phase ϕ ≈ 0.43. The lack of radio detection in two out of three observing epochs at ϕ ≈ 0.43 suggests that either the radio emission is not linked with a particular pulsation phase, or else that the strength of the generated radio emission in each pulsation cycle is variable. |
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| Date de publication | 2023-02-09 |
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| Maison d’édition | IOP |
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| Dans | |
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| Langue | anglais |
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| Publications évaluées par des pairs | Oui |
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| Exporter la notice | Exporter en format RIS |
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| Signaler une correction | Signaler une correction (s'ouvre dans un nouvel onglet) |
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| Identificateur de l’enregistrement | 08940431-0847-4660-b9af-3075d83aae13 |
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| Enregistrement créé | 2024-06-04 |
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| Enregistrement modifié | 2024-06-04 |
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