Seven-year periodic variations in the methanol maser line displayed by the massive protostar IRAS 20216+4104
| Autor: | Szymczak, M., Durjasz, M., Goedhart, S., Wolak, P., Bartkiewicz, A., Garatti, A. Caratti o, Kobak, A., Massi, F. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Aims: We report the discovery and analysis of a periodic methanol maser in the massive protostar IRAS 20216+4104. Methods: To obtain the light curve, we used the 6.7 GHz methanol maser spectra collected between 2000-2003 and 2009-2023 with the Hartebeesthoek and Torun radio telescopes, as well as spectra from the literature reported prior to 1992. Results: The velocity-integrated flux density shows sinusoidal-like variations with a period of 6.9 +/- 0.03 yr. All but one of the features show periodic changes with a relative amplitude of 2 up to >89. A slightly variable feature displays a moderate anti-correlation between the flux density and the other significantly variable features. The maser emission appears to follow the continuum emission of the red-shifted outflow cavity. A maximum emission of 3.4 and 4.6 mu m precedes the maser peak by 15 % of the period and the (infrared) IR light centroids show time-dependent displacement. The periodic behaviour of the maser and IR emission is likely due to the eclipsing effect from a wobbling inner disk. Comment: 10 figures, 2 tables, accepted by A&A |
| Databáze: | arXiv |
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