A precise measurement of the magnetic field in the corona of the black hole binary V404 Cygni

Yigit Dallilar, Stephen S. Eikenberry, Alan Garner, Richard D. Stelter, Amy Gottlieb, Poshak Gandhi, Piergiorgio Casella, Vik S. Dhillon, Tom R. Marsh, Stuart P. Littlefair, Liam Hardy, Rob Fender, Kunal Mooley, Dominic J. Walton, Felix Fuerst, Matteo Bachetti, A. J. Castro-Tirado, Miguel Charcos, Michelle L. Edwards, Nestor M. Lasso-CabreraAntonio Marin-Franch, S. Nicholas Raines, Kendall Ackley, John G. Bennett, A. Javier Cenarro, Brian Chinn, H. Veronica Donoso, Raymond Frommeyer, Kevin Hanna, Michael D. Herlevich, Jeff Julian, Paola Miller, Scott Mullin, Charles H. Murphey, Chris Packham, Frank Varosi, Claudia Vega, Craig Warner, A. N. Ramaprakash, Mahesh Burse, Sujit Punnadi, Pravin Chordia, Andreas Gerarts, Héctor De Paz Martín, María Martín Calero, Riccardo Scarpa, Sergio Fernandez Acosta, William Miguel Hernández Sánchez, Benjamin Siegel, Francisco Francisco Pérez, Himar D. Viera Martín, José A. Rodríguez Losada, Agustín Nuñez, Álvaro Tejero, Carlos E. Martín González, César Cabrera Rodríguez, Jordi Molgó, J. Esteban Rodriguez, J. Israel Fernández Cáceres, Luis A. Rodríguez García, Manuel Huertas Lopez, Raul Dominguez, Tim Gaggstatter, Antonio Cabrera Lavers, Stefan Geier, Peter Pessev, Ata Sarajedini

Research output: Contribution to journalArticleResearchpeer-review

8 Citations (Scopus)


Observations of binary stars containing an accreting black hole or neutron star often show x-ray emission extending to high energies (>10 kilo–electron volts), which is ascribed to an accretion disk corona of energetic particles akin to those seen in the solar corona. Despite their ubiquity, the physical conditions in accretion disk coronae remain poorly constrained. Using simultaneous infrared, optical, x-ray, and radio observations of the Galactic black hole system V404 Cygni, showing a rapid synchrotron cooling event in its 2015 outburst, we present a precise 461 ± 12 gauss magnetic field measurement in the corona. This measurement is substantially lower than previous estimates for such systems, providing constraints on physical models of accretion physics in black hole and neutron star binary systems.

Original languageEnglish
Pages (from-to)1299-1302
Number of pages4
Issue number6368
Publication statusPublished - 8 Dec 2017
Externally publishedYes

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