A study on evolved stars by simultaneous observations of H2O and SiO masers using KVN
| Autor: | Youngjoo Yun, Y. K. Choi, Richard Dodson, Maria Rioja, Jaeheon Kim, Dong-Hwan Yoon, Se-Hyung Cho, Hiroshi Imai, Dong-Jin Kim |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences Spatial structure Phase (waves) Astronomy and Astrophysics Astrophysics 01 natural sciences law.invention Stars Space and Planetary Science law 0103 physical sciences Very-long-baseline interferometry Radiative transfer Millimeter Supergiant Maser 010303 astronomy & astrophysics 0105 earth and related environmental sciences |
| Zdroj: | Proceedings of the International Astronomical Union. 13:359-364 |
| ISSN: | 1743-9221 1743-9213 |
| DOI: | 10.1017/s1743921317010274 |
| Popis: | The Korean VLBI Network (KVN) is a unique millimeter VLBI system which is consisted of three 21 m telescopes with relatively short baselines. We present the preliminary results of simultaneous monitoring observations of the 22.2 GHz H2O and 43.1/42.8/86.2/129.3 GHz SiO masers based on the KVN Key Science Project (KSP). We obtained the astrometrically registered maps of the H2O and SiO masers toward nine evolved stars using the source frequency phase referencing method (SFPR). The SFPR maps of the H2O and SiO masers enabled us to investigate the spatial structure and kinematics from the SiO to H2O maser regions including the development of an outward motion from the ring-like or elliptical structures of SiO masers to the asymmetric structures of the 22.2 GHz H2O maser features. In particular, the 86.2/129.3 GHz SiO (v=1, J=2–1 and J=3–2) masers were clearly imaged toward several objects for the first time. The SiO v=1, J=3–2 maser shows different distributions compared to those of the SiO v=1, 2, J=1–0 and v=1, J=2–1 masers implying a different physical condition. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|