Twelve-year simultaneous monitoring of the SiO and H2O masers toward AGB stars: RT Vir, RR Aql, IRC-10151

  • Son, Seong Min (Department of Astronomy and Space Sciences, Chungbuk National University) ;
  • Kim, Jaeheon (Radio Astronomy Division, Korea Astronomy and Space Science Institute) ;
  • Lim, Jang Ho (Department of Astronomy and Space Sciences, Chungbuk National University) ;
  • Suh, Kyung-Won (Department of Astronomy and Space Sciences, Chungbuk National University) ;
  • Cho, Se-Hyung (Radio Astronomy Division, Korea Astronomy and Space Science Institute) ;
  • Yoon, Dong-Hwan (Radio Astronomy Division, Korea Astronomy and Space Science Institute) ;
  • Yang, Haneul (Radio Astronomy Division, Korea Astronomy and Space Science Institute)
  • Published : 2021.10.13

Abstract

We present the results of long-term simultaneous monitoring observations (~ 12 years) of H2O (22 GHz) maser and several vibrationally excited lines of SiO J = 1-0, 2-1, 3-2 masers (43, 86, 129 GHz) carried out with the 21-m antennas of the Korean VLBI Network (KVN) toward a sample of three AGB stars (RT Vir, RR Aql, IRC-10151) that are believed to be semiregular variable star, Mira variable star, and OH/IR star, respectively, according to a sequential evolutionary phase of AGB star. A total 10 transitions were observed, of which we detected H2O, SiO 𝝊 = 1 and 2, J = 1-0, SiO 𝝊 = 1, J = 2-1 and J = 3-2 maser lines in all three target objects, depending on the observational epochs. In this study, we scrutinize the evolutionary traits of each target object based on the maser line profiles, flux/velocity variations, and phase lags with the optical light curves. The IRAS two color diagram and the infrared spectral energy distributions (SEDs) in the wavelength range from 1.2 to 240 ㎛ of three observed sources were also analyzed.

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