A warped m= 2 water maser disc in V778 Cyg?
| Autor: | Juri Poutanen, Natalia Babkovskaia, Anita M. S. Richards, R. Szczerba |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Coupling
Physics Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Radius Carbon star Silicate law.invention chemistry.chemical_compound chemistry Space and Planetary Science law Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Binary system Maser Impact parameter Astrophysics::Galaxy Astrophysics Dust emission |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 370:1921-1927 |
| ISSN: | 0035-8711 |
| Popis: | The silicate carbon star V778 Cyg is a source of 22 GHz water maser emission which was recently resolved by MERLIN. Observations revealed an elongated S-like structure along which the velocities of the maser features show a linear dependence on the impact parameter. This is consistent with a doubly-warped m=2 disc observed edge-on. Water masers and silicate dust emission (detected by IRAS and ISO) have a common origin in O-rich material and are likely to be co-located in the disc. We propose a detailed self-consistent model of a masing gas-dust disc around a companion to the carbon star in a binary system, which allows us to estimate the companion mass of 1.7 +- 0.1 M_sun, the disc radius of 40 +-3 AU and the distance between companions of about 80 AU. Using a dust-gas coupling model for water masing, we calculate the maser power self-consistently, accounting for both the gas and the dust energy balances. Comparing the simulation results with the observational data, we deduce the main physical parameters of the masing disc, such as the gas and dust temperatures and their densities. We also present an analysis of the stability of the disc. |
| Databáze: | OpenAIRE |
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