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

We report results from a Giant Metrewave Radio Telescope (GMRT) monitoringcampaign on the black hole X-ray binary V404 Cygni during its 2015 Juneoutburst. The GMRT observations were carried out at observing frequencies of1280, 610, 325 and 235 MHz, and extended from June 26.89 UT (a day after thestrongest radio/X-ray outburst) to July 12.93 UT. We find the low-frequencyradio emission of V404 Cygni to be extremely bright and fast-decaying in theoutburst phase, with an inverted spectrum below 1.5 GHz and an intermediateX-ray state. The radio emission settles to a weak, quiescent state $\approx 11$days after the outburst, with a flat radio spectrum and a soft X-ray state.Combining the GMRT measurements with flux density estimates from theliterature, we identify a spectral turnover in the radio spectrum at $\approx1.5$ GHz on $\approx$ June 26.9 UT, indicating the presence of a synchrotronself-absorbed emitting region. We use the measured flux density at the turnoverfrequency with the assumption of equipartition of energy between the particlesand the magnetic field to infer the jet radius ($\approx 4.0 \times 10^{13}$cm), magnetic field ($\approx 0.5$ G), minimum total energy ($\approx 7 \times10^{39}$ ergs) and transient jet power ($\approx 8 \times 10^{34}$ ergs$^{-1}$). The relatively low value of the jet power, despite V404 Cygni's highblack hole spin parameter, suggests that the radio jet power does not correlatewith the spin parameter.

Giant Metrewave Radio Telescope monitoring of the black hole X-ray binary, V404 Cygni, during its June 2015 outburst