학술논문
Follow-up Observations for IceCube-170922A: Detection of Rapid Near-Infrared Variability and Intensive Monitoring of TXS 0506+056
Document Type
Working Paper
Author
Morokuma, Tomoki; Utsumi, Yousuke; Ohta, Kouji; Yamanaka, Masayuki; Kawabata, Koji S.; Inoue, Yoshiyuki; Tanaka, Masaomi; Yoshida, Michitoshi; Itoh, Ryosuke; Sasada, Mahito; Tominaga, Nozomu; Mori, Hiroki; Kawabata, Miho; Nakaoka, Tatsuya; Chogi, Maiko; Abe, Taisei; Huang, Ruochen; Kawahara, Naoki; Kimura, Hiroki; Nagashima, Hiroki; Takagi, Kengo; Yamazaki, Yuina; Liu, Wei; Ohsawa, Ryou; Sako, Shigeyuki; Murata, Katsuhiro L.; Morihana, Kumiko; Gilligan, Christina K.; Isogai, Keisuke; Kimura, Mariko; Wakamatsu, Yasuyuki; Ohnishi, Ryuhei; Takayama, Masaki; Honda, Satoshi; Matsuoka, Yoshiki; Yamashita, Takuji; Nagataki, Shigehiro; Tanaka, Yasuyuki T.
Source
Subject
Language
Abstract
We present our follow-up observations to search for an electromagnetic counterpart of the IceCube high-energy neutrino, IceCube-170922A. Monitoring observations of a likely counterpart, TXS 0506+056, are also described. First, we quickly took optical and near-infrared images of 7 flat-spectrum radio sources within the IceCube error region right after the neutrino detection and found a rapid flux decline of TXS 0506+056 in Kanata/HONIR J-band data. Motivated by this discovery, intensive follow-up observations of TXS 0506+056 are continuously done, including our monitoring imaging observations, spectroscopic observations, and polarimetric observations in optical and near-infrared wavelengths. TXS 0506+056 shows a large amplitude (~1.0 mag) variability in a time scale of several days or longer, although no significant variability is detected in a time scale of a day or shorter. TXS 0506+056 also shows a bluer-when-brighter trend in optical and near-infrared wavelengths. Structure functions of variabilities are examined and indicate that TXS 0506+056 is not a special blazar in terms of optical variability. Polarization measurement results of TXS 0506+056 are also discussed.
Comment: 19 pages, 10 figures, 4 tables. Accepted for publication in Publications of the Astronomical Society of Japan (PASJ)
Comment: 19 pages, 10 figures, 4 tables. Accepted for publication in Publications of the Astronomical Society of Japan (PASJ)