# Dynamically important magnetic fields near the event horizon of Sgr A*

@article{JimnezRosales2020DynamicallyIM,
title={Dynamically important magnetic fields near the event horizon of Sgr A*},
author={Alejandra Jim{\'e}nez-Rosales and Jason Dexter and Felix Widmann and Michi Baub{\"o}ck and Roberto Abuter and Ant{\'o}nio Amorim and J. P. Berger and Henri Bonnet and Wolfgang Brandner and Yann Cl'enet and P. Tim de Zeeuw and Andreas Eckart and Frank Eisenhauer and Natascha M. F{\"o}rster Schreiber and P. Garcia and Feng Gao and Eric Gendron and Reinhard Genzel and Stefan Gillessen and Maryam Habibi and X. Haubois and Gernot Hei{\ss}el and Th. Henning and Stephen Hippler and M. Horrobin and L. Jochum and L. Jocou and A. Kaufer and Pierre Kervella and Sylvestre Lacour and Vincent Lapeyr{\e}re and Jean-Baptiste Le Bouquin and Pierre L'ena and M. Nowak and Thomas Ott and T. Paumard and K. Perraut and Guy Perrin and Oliver Pfuhl and Gustavo Rodr'iguez-Coira and Jinyi Shangguan and Silvia Scheithauer and J. Stadler and Odele Straub and C. Straubmeier and Eckhard Sturm and Linda J. Tacconi and Frederic H. Vincent and Sebastiano D. von Fellenberg and Idel Waisberg and Ekkehard Wieprecht and Erich Wiezorrek and Julien Woillez and S. Yazici and G{\'e}rard Zins},
journal={Astronomy \& Astrophysics},
year={2020}
}`
• Published 3 September 2020
• Physics
• Astronomy & Astrophysics
We study the time-variable linear polarisation of Sgr A* during a bright near-infrared flare observed with the GRAVITY instrument on July 28, 2018. Motivated by the time evolution of both the observed astrometric and polarimetric signatures, we interpret the data in terms of the polarised emission of a compact region (“hotspot”) orbiting a black hole in a fixed, background magnetic field geometry. We calculated a grid of general relativistic ray-tracing models, created mock observations by…

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