Abstract
The results of observations of the H2O and OH maser sources toward the region of W33C (G12.8-0.2) are reported. The observations were carried out on the 22-m radio telescope of the Pushchino Radio Astronomy Observatory in the 1.35-cm water-vapor line and on the Large Radio Telescope at Nançay (France), in the main (1665 and 1667 MHz) and satellite (1612 and 1720 MHz) OH lines. Multiple, strongly variable, short-lived H2O emission features were detected in a broad interval of radial velocities, from −7 to 55 km/s. OH maser emission in the 1667-MHz line was detected at velocities of 35–41 km/s. The Stokes parameters of the maser emission in the main OH lines 1665 and 1667 MHz were measured. Zeeman splitting was detected in the 1665-MHz line at 33.4 and 39.4 km/s, and in the 1667 MHz line only at 39.4 km/s. The magnetic-field intensity was estimated. Appreciable variability of the Zeeman splitting components was observed at 39 and 39.8 km/s in both main lines. The extended spectrum and fast variability of the H2O maser emission, together with the variability of the Zeeman-splitting components in the main OH lines, may indicate a composite clumpy structure of the molecular cloud and the presence of large-scale rotation, bipolar outflows, and turbulent motions of material in this cloud.
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Original Russian Text © P. Colom, E.E. Lekht, M.I. Pashchenko, G.M. Rudnitskii, 2012, published in Astronomicheskii Zhurnal, 2012, Vol. 89, No. 10, pp. 811–820.
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Colom, P., Lekht, E.E., Pashchenko, M.I. et al. The source of maser emission in W33C (G12.8-0.2). Astron. Rep. 56, 731–740 (2012). https://doi.org/10.1134/S1063772912100034
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DOI: https://doi.org/10.1134/S1063772912100034