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Shocks and dust formation in nova V809 Cepстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Babul Aliya-Nur, Sokoloski Jennifer L., Chomiuk Laura, Linford Justin D., Weston Jennifer H.S., Aydi Elias, Sokolovsky Kirill V., Kawash Adam M., Mukai Koji
- Журнал: Monthly Notices of the Royal Astronomical Society
- Том: 515
- Номер: 2
- Год издания: 2022
- Издательство: Oxford Journals, Oxford University Press
- Местоположение издательства: Oxford, UK, England
- Первая страница: 3028
- Последняя страница: 3036
- DOI: 10.1093/mnras/stac1366
- Аннотация: The discovery that many classical novae produce detectable GeV γ-ray emission has raised the question of the role of shocks in nova eruptions. Here, we use radio observations of nova V809 Cep (nova Cep 2013) with the Jansky Very Large Array to show that it produced non-thermal emission indicative of particle acceleration in strong shocks for more than a month starting about 6 weeks into the eruption, quasi-simultaneous with the production of dust. Broadly speaking, the radio emission at late times - more than 6 months or so into the eruption - is consistent with thermal emission from 10−4M⊙ of freely expanding, 104 K ejecta. At 4.6 and 7.4 GHz, however, the radio light curves display an initial early-time peak 76 d after the discovery of the eruption in the optical (t0). The brightness temperature at 4.6 GHz on day 76 was greater than 105 K, an order of magnitude above what is expected for thermal emission. We argue that the brightness temperature is the result of synchrotron emission due to internal shocks within the ejecta. The evolution of the radio spectrum was consistent with synchrotron emission that peaked at high frequencies before low frequencies, suggesting that the synchrotron from the shock was initially subject to free-free absorption by optically thick ionized material in front of the shock. Dust formation began around day 37, and we suggest that internal shocks in the ejecta were established prior to dust formation and caused the nucleation of dust.
- Добавил в систему: Самусь Николай Николаевич