On 2015 June 15 the Swift space observatory discovered that the Galactic black hole candidate V404 Cyg was undergoing another active X-ray phase, after 25 years of inactivity (Barthelmy et al. 2015). Twelve telescopes of the MASTER Global Robotic Net located at six sites across four continents were the first ground based observatories to start optical monitoring of the microquasar after its gamma-ray wakeup at 18h 34m 09s U.T. on 2015 June 15 (Lipunov et al. 2015). In this paper we report, for the first time, the discovery of variable optical linear polarization, changing by 4-6% over a timescale of approximately 1 h, on two different epochs. We can conclude that the additional variable polarization arisies from the relativistic jet generated by the black hole in V404Cyg. The polarization variability correlates with optical brightness changes, increasing when the flux decreases.
@article{arxiv.1608.02764,
title = {MASTER optical polarization variability detection in the Microquasar V404 Cyg/GS2023+33},
author = {Vladimir M. Lipunov and E. Gorbovskoy and V. Kornilov and V. Krushinskiy and D. Vlasenko and N. Tiurina and P. Balanutsa and A. Kuznetsov and N. Budnev and O. Gress and A. Tlatov and R. Rebolo Lopez and M. Serra-Ricart and D. A. H. Buckley and G. Israelian and N. Lodieu and K. Ivanov and S. Yazev and Yu. Sergienko and A. Gabovich and V. Yurkov and H. Levato and C. Saffe and R. Podesta and C. Mallamaci and C. Lopez},
journal= {arXiv preprint arXiv:1608.02764},
year = {2016}
}
Comments
10 pages, 1 figures, 4 tables, accepted for publication in the The Astrophysical Journal