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arXiv · 1003.1962

Proper Motions of H2O Masers in the Water Fountain Source IRAS 19190+1102

F. M. Day·Y. M. Pihlstrom·M. J. Claussen·R. Sahai
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Abstract

We report on the results of two epochs of Very Long Baseline Array (VLBA) observations of the 22 GHz water masers toward IRAS 19190+1102. The water maser emission from this object shows two main arc-shaped formations perpendicular to their NE-SW separation axis. The arcs are separated by ~280 mas in position, and are expanding outwards at an angular rate of 2.35 mas/yr. We detect maser emission at velocities between -53.3 km/s to +78.0 km/s and there is a distinct velocity pattern where the NE masers are blueshifted and the SW masers are redshifted. The outflow has a three-dimensional outflow velocity of 99.8 km/s and a dynamical age of about 59 yr. A group of blueshifted masers not located along the arcs shows a change in velocity of more than 35 km/s between epochs, and may be indicative of the formation of a new lobe. These observations show that IRAS 19190+1102 is a member of the class of "water fountain"' pre-planetary nebulae displaying bipolar structure

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F. M. Day, Y. M. Pihlstrom, M. J. Claussen, R. Sahai. 2010-03-22. Proper Motions of H2O Masers in the Water Fountain Source IRAS 19190+1102. https://doi.org/10.1088/0004-637x%2F713%2F2%2F986

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