Radio observations of outburst from V404 Cyg at 1.4GHz
ATel #7701; K. Tsubono, T. Aoki, K. Asuma, T. Daishido, S. Kida, H. Nakajima (Waseda Univ.), K. Niinuma (Yamaguchi Univ.), and K. Takefuji (NICT)
on 23 Jun 2015; 23:55 UT
Credential Certification: Kimio Tsubono (tsubono.kimio@aoni.waseda.jp)
Subjects: Radio, Binary, Black Hole, Transient
Waseda University Nasu radio telescope is a spatial FFT interferometer comprising linearly aligned eight-elements antenna array with 20m-diameter spherical dishes. Using this antenna array, we have been conducting a series of drift-scan 1.4GHz radio observations at the declination of 33.73 degrees since May 18 this year.
On 2015 June 21 17:24 UT, we found a significant peak at the position near V404 Cyg (ATel #7667, #7661, #7658, #7646), though on June 20 17:28 UT we could not observe any noticeable signal at that region.
The coordinates and flux of the observed radio source are;
R.A.: 20h24m04.6 +/- 03s,
Dec.: 33.73 +/- 0.4 degrees,
flux: 313 +/- 30 mJy.
Next day, on June 22 17:20 UT, the observed flux was decreasing to 194 +/- 30 mJy.
We will continue this radio observations.