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arXiv · 1412.8251

First detection of 22 GHz H2O masers in TX Camelopardalis

Se-Hyung Cho·Jaeheon Kim·Youngjoo Yun
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Abstract

Simultaneous time monitoring observations of H$_{2}$O $6_{16}-5_{23}$, SiO $J$ = 1--0, 2--1, 3--2, and $^{29}$SiO $v$ = 0, $J$ = 1--0 lines were carried out in the direction of the Mira variable star TX Cam with the Korean VLBI Network single dish radio telescopes. For the first time, the H$_{2}$O maser emission from TX Cam was detected near the stellar velocity at five epochs from April 10, 2013 ($\phi$ = 3.13) to June 4, 2014 ($\phi$ = 3.89) including minimum optical phases. The intensities of H$_{2}$O masers are very weak compared to SiO masers. The variation of peak antenna temperature ratios among SiO $v$ = 1, $J$ = 1--0, $J$ = 2--1, and $J$ = 3--2 masers is investigated according to their phases. The shift of peak velocities of H$_{2}$O and SiO masers with respect to the stellar velocity is also investigated according to observed optical phases. The H$_{2}$O maser emission occurs around the stellar velocity during our monitoring interval. On the other hand, the peak velocities of SiO masers show a spread compared to the stellar velocity. The peak velocities of SiO $J$ = 2--1, and $J$ = 3--2 masers show a smaller spread with respect to the stellar velocity than those of SiO $J$ = 1--0 masers. These simultaneous observations of multi-frequencies will provide a good constraint for maser pumping models and a good probe for investigating the stellar atmosphere and envelope according to their different excitation conditions.

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Se-Hyung Cho, Jaeheon Kim, Youngjoo Yun. 2014-12-29. First detection of 22 GHz H2O masers in TX Camelopardalis. https://doi.org/10.5303/jkas.2014.47.6.293

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