English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Waseda University Nasu telescope array is a spatial fast Fourier transform(FFT) interferometer consisting of eight linearly aligned antennas with 20 mspherical dishes. This type of interferometer was developed to survey transientradio sources with an angular resolution as high as that of a 160 m dish with afield of view as wide as that of a 20 m dish. We have been performingdrift-scan-mode observations, in which the telescope scans the sky around aselected declination as the earth rotates. The black hole X-ray binary V404Cygni underwent a new outburst in 2015 June after a quiescent period of 26years. Because of the interest in black hole binaries, a considerable amount ofdata on this outburst at all wavelengths was accumulated. Using the abovetelescope, we had been monitoring V404 Cygni daily from one month before theX-ray outburst, and two radio flares at 1.4 GHz were detected on June 21.73 andJune 26.71. The flux density and time-scale of each flare were 313+/-30 mJy and1.50+/-0.49 days, 364+/-30 mJy and 1.70+/-0.16 days, respectively. We have alsoconfirmed the extreme variation of radio spectra within a short period bycollecting other radio data observed with several radio telescopes. Suchspectral behaviors are considered to reflect the change in the opacity of theejected blobs associated with these extreme activities in radio and X-ray. Our1.4 GHz radio data are expected to be helpful for studying the physics of theaccretion and ejection phenomena around black holes.

Observations of V404 Cygni during the 2015 outburst by the Nasu telescope array at 1.4 GHz