Open AccessLong-term with short-intervals monitor of 6.7 GHz CH3OH masers using Hitachi 32-m radio telescope to statistically research the periodic flux variability around high-mass protostars
Author(s) -
Koichiro Sugiyama,
Yoshinori Yonekura,
Kazuhito Motogi,
Shenghua Yu,
Munetake Momose,
Mareki Honma,
Tomoya Hirota,
Mitsuru Uchiyama,
Kei E. I. Tanaka,
B. Hutawarakorn Kramer,
K. Asanok,
Phrudth Jaroenjittichai,
Kenta Fujisawa
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1380/1/012057
Subject(s) - maser , flux (metallurgy) , radio telescope , astrophysics , physics , telescope , protostar , environmental science , stars , star formation , materials science , metallurgy
We initiated a long-term with short-intervals monitoring project toward 442 CH 3 OH masers at 6.7 GHz (Dec > -30 deg) using Hitachi 32-m radio telescope of Japan in Dec 2012. Our observations have been carried out daily, monitoring a spectrum of each source with intervals of 9-10 days. In Sep 2015, the number of the targets sources and intervals were redesigned into 143 and 4-5 days to detect periodic variations with periods shorter than 30 days. We have so far obtained new detections of periodic flux variations in 31 CH 3 OH sources with periods of 22-409 days. These periodic flux variability with timescale between a few months and a few years must be a unique tool to study high-mass protostars themselves and their circumstellar structures on a tiny spatial scale of 0.1-1 au (∼1.5 x 10 7-8 km). We will also present the future prospect via monitoring of OH and H 2 O masers in these periodic sources using 40-m Thai National Radio Telescope that is under construction by NARIT.