A radio parallax to the black hole X-ray binary MAXI J1820+070

P. Atri, J. C. A. Miller-Jones, A. Bahramian, R. M. Plotkin, A. T. Deller, P. G. Jonker, T. J. Maccarone, G. R. Sivakoff, R. Soria, D. Altamirano, T. Belloni, R. Fender, E. Koerding, D. Maitra, S. Markoff, S. Migliari, D. Russell, T. Russell, C. L. Sarazin, A. J. TetarenkoV. Tudose

Research output: Contribution to journalArticle


Using the Very Long Baseline Array and the European Very Long Baseline Interferometry Network we have made a precise measurement of the radio parallax of the black hole X-ray binary MAXI\,J1820+070, providing a model-independent distance to the source. Our parallax measurement of $0.348\pm0.033$ mas for MAXI\,J1820+070 translates to a distance of $2.96\pm0.33$ kpc. This distance implies that the source reached $15\pm3\%$ of the Eddington luminosity at the peak of its outburst. Further, we use this distance to refine previous estimates of the jet inclination angle, jet velocity and the mass of the black hole in MAXI J1820+070 to be $62\pm3^{\circ}$, $0.88\pm0.09c$ and $9.5\pm1.4 M_{\odot}$, respectively
Original languageEnglish (US)
JournalMonthly Notices of the Royal Astronomical Society
StateAccepted/In press - Jan 1 2020



  • Astrophysics - High Energy Astrophysical Phenomena

Cite this

Atri, P., Miller-Jones, J. C. A., Bahramian, A., Plotkin, R. M., Deller, A. T., Jonker, P. G., Maccarone, T. J., Sivakoff, G. R., Soria, R., Altamirano, D., Belloni, T., Fender, R., Koerding, E., Maitra, D., Markoff, S., Migliari, S., Russell, D., Russell, T., Sarazin, C. L., ... Tudose, V. (Accepted/In press). A radio parallax to the black hole X-ray binary MAXI J1820+070. Monthly Notices of the Royal Astronomical Society.