천문학회보 (The Bulletin of The Korean Astronomical Society)
- 제41권1호
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- Pages.73.2-73.2
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- 2016
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- 1226-2692(pISSN)
SgrA* 22/43GHz KaVA observation and its Amplitude Calibration
- CHO, ILJE (Korea Astronomy and Space science Institute(KASI)) ;
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JUNG, TAEHYUN
(Korea Astronomy and Space science Institute(KASI)) ;
- ZHAO, GUANG-YAO (Korea Astronomy and Space science Institute(KASI)) ;
- KINO, MOTOKI (Korea Astronomy and Space science Institute(KASI)) ;
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SOHN, BONGWON
(Korea Astronomy and Space science Institute(KASI))
- 발행 : 2016.04.12
초록
We present the results of KaVA SgrA* observation together with Takahagi(32m), Yamaguchi(32m) and Nobeyama(45m) telescopes at 22 and 43GHz, respectively. In early 2014, G2 cloud was expected to encounter with SgrA* and to make a significant flux variation, but it has not been measured yet. So it's worth to check our amplitude calibration method to confirm if we have a missing flux caused by uncertainty in measuring it. We have tested both a standard method using system noise temperature(Tsys) with antenna gain information, and a template method in order to calibrate antenna gain using nearby maser source. As a result, we found that the latter method is useful for antennas which have inaccurate gain information or poor Tsys measurements, and is especially effective for sources at low elevation like SgrA*. In addition, the comparison shows that the amplitude calibration by standard method can be improved up to 10% with a correction factor using a template method. This result implies we can get more accurate flux from a standard method when any maser source not exists around target.
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