Long-term multi-frequency maser observations of the intermediate-mass young stellar object G107.298+5.639
| العنوان: | Long-term multi-frequency maser observations of the intermediate-mass young stellar object G107.298+5.639 |
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| المؤلفون: | M. Szymczak, M. Olech, Eric Gérard, Anna Bartkiewicz, Paweł Wolak |
| المساهمون: | Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Szymczak, Marian |
| المصدر: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 634, pp.A41. ⟨10.1051/0004-6361/201936943⟩ |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | Infrared, Young stellar object, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, Luminosity, Radio telescope, ISM [radio lines], masers, law, 0103 physical sciences, Very-long-baseline interferometry, Astrophysics::Solar and Stellar Astrophysics, Maser, Physics::Chemical Physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, [PHYS]Physics [physics], Physics, formation [stars], 010308 nuclear & particles physics, Astronomy and Astrophysics, Light curve, Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics, instabilities, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], clouds [ISM] |
| الوصف: | Periodic flares of maser emission are thought to be induced either by variations of the seed photon flux in young binary systems or the pump rate regulated by stellar and accretion luminosities. We seek to study the variability of four maser transitions of three different species in G107.298+5.639 to constrain the dominant mechanism of periodic flares. Light curves of the 6.7 GHz methanol and 22.2 GHz water vapour maser were obtained with the Torun 32m radio telescope over 39 and 34 cycles, respectively. The target was also monitored at the 1.6 GHz hydroxyl transitions with the Nan\c{c}ay radio telescope over 13 cycles. All these maser lines were imaged using VLBI arrays. The study confirms alternating flares of the methanol and water masers with a period of 34.4d and reveals the synchronised behaviour of the methanol and hydroxyl masers in this source. The observed spatial distribution of the methanol maser cloudlets and the measured time delays of the flares of individual features imply a ring-like structure of radius 240au and thickness 30au. Internal proper motions indicate that the velocity of methanol cloudlets is dominated by a disc-wind component of about 5km/s. The methanol emission detected during only one VLBI observation is located in a region about 550au from a central star, which also exhibits OH maser flares. The erratic appearance of methanol features can be related to a powering object of relatively low luminosity which, during some variability cycles, can excite molecules only in the nearest part of the disc. A careful analysis of the maser and infrared light curves reveal a strong correlation between the 6.7 GHz line and the infrared flux densities supporting a radiative pumping of the maser. The synchronised behaviour of the hydroxyl and methanol transitions indicates a common pumping mechanism for the periodic flares of G107.298+5.639. Comment: 20 pages, 15 figures |
| اللغة: | English |
| تدمد: | 0004-6361 |
| DOI: | 10.1051/0004-6361/201936943⟩ |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::43069eff0738ed4870a94f5cfef9225e http://arxiv.org/abs/2001.01625 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....43069eff0738ed4870a94f5cfef9225e |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 00046361 |
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| DOI: | 10.1051/0004-6361/201936943⟩ |