Evolution of superflares of H₂O maser emission in IRAS 16293-2422

Pierre Colom (1) , N. T. Ashimbaeva , E. E. Lekht , M. I. Pashchenko , G. M. Rudnitskij , V. V. Krasnov , A. M. Tolmachev

1 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics

The aim of this work was to continue the monitoring of the H₂O maser emission in IRAS 16293-2422 to detect superflares. We have been observing H₂O maser emission at a wavelength of 1.35 cm towards the source IRAS 16293-2422 since 1999. The observations have been carried out with the 22-m radio telescope of the Pushchino Radio Astronomy Observatory (Russia). In 2007-2018, we also conducted several sessions of observations in OH lines at a wavelength of 18 cm in both circular polarizations with the Nançay Radio Telescope (France). Between 1997 and 2021, we observed three cycles of high activity of the H₂O maser with a period of 8 yr. This variability could be related to the changing activity of the protostar in the tight binary system of IRAS 16293-2422 in the process of its formation. This variability could be related to an increase in the activity of the tight binary protostar IRAS 16293-2422 A, first seen in 2002. The H₂O maser variation in flux density and radial velocity suggests that disturbances are propagating through organized structures in the form of chains ~3.5 au long, with monotonic velocity gradients in the direction of propagation. The 18-cm OH emission in the main and satellite lines is thermal.

Keywords: masers; star: activity; stars: formation; ISM: jets and outflows

Domains: Sciences of the Universe [physics]

Pierre Colom, N. T. Ashimbaeva, E. E. Lekht, M. I. Pashchenko, G. M. Rudnitskij, et al.. Evolution of superflares of H₂O maser emission in IRAS 16293-2422. Monthly Notices of the Royal Astronomical Society, 2021, 507, pp.3285-3291. ⟨10.1093/mnras/stab2287⟩. ⟨insu-03713746⟩