683 citations · 1.3k across the 17 of their papers we have counts for
17 papers
Signatures of Black Hole Spin in Horizon-Scale Polarimetry
George N. Wong, Daniel C. M. Palumbo, Zachary Gelles +1
The angular momentum of a black hole, usually expressed in terms of a dimensionless "spin," both shapes the strong-field spacetime and provides a reservoir of rotational energy tha…
Black Hole Polarimetry: Universal Polarization of Synchrotron Radiation at the Horizon
Andrew Chael, Alexandru Lupsasca, George N. Wong +2
Polarized images of a black hole encode the direction of electromagnetic energy flow near its event horizon. Measuring polarization from near-horizon emission can help determine wh…
A Nonlinear Endpoint of Charged Horizon Instabilities
Zachary Gelles, Frans Pretorius
We numerically construct asymptotically extremal black holes through the nonlinear evolution of a charged scalar field. Our procedure -- which extends the work of Murata-Reall-Tana…
Signatures of Black Hole Spin and Plasma Acceleration in Jet Polarimetry II: Off-Axis Jets
Zachary Gelles, Andrew Chael, Eliot Quataert
We analyze the polarization of optically thin, stationary, axisymmetric black hole jets at scales of order the light cylinder radius. Our work generalizes the face-on results of Ge…
Accumulation of Charge on an Extremal Black Hole's Event Horizon
Zachary Gelles, Frans Pretorius
We numerically analyze the behavior of a charged scalar field on a fixed extremal Reissner-Nordström background. We find an extension of the Aretakis instability characterized by a…
Limb-Brightened Jet in M87 from Anisotropic Nonthermal Electrons
Yuh Tsunetoe, Dominic W. Pesce, Ramesh Narayan +5
Very long baseline interferometry observations reveal that relativistic jets like the one in M87 have a limb-brightened, double-edged structure. Analytic and numerical models strug…
Signatures of Black Hole Spin and Plasma Acceleration in Jet Polarimetry
Zachary Gelles, Andrew Chael, Eliot Quataert
We study the polarization of black hole jets on scales of and show that large spatial swings in the polarization occur at three characteristic distances from the…
The Black Hole Explorer: Motivation and Vision
Michael D. Johnson, Kazunori Akiyama, Rebecca Baturin +65
We present the Black Hole Explorer (BHEX), a mission that will produce the sharpest images in the history of astronomy by extending submillimeter Very-Long-Baseline Interferometry…
Polarimetry and Astrometry of NIR Flares as Event Horizon Scale, Dynamical Probes for the Mass of Sgr A*
The GRAVITY Collaboration, R. Abuter, N. Aimar +66
We present new astrometric and polarimetric observations of flares from Sgr A* obtained with GRAVITY, the near-infrared interferometer at ESO's Very Large Telescope Interferometer…
Relativistic Signatures of Flux Eruption Events Near Black Holes
Zachary Gelles, Koushik Chatterjee, Michael Johnson +2
Images of supermassive black holes produced using very long baseline interferometry provide a pathway to directly observing effects of a highly curved spacetime, such as a bright `…
Bayesian Accretion Modeling: Axisymmetric Equatorial Emission in the Kerr Spacetime
Daniel C. M Palumbo, Zachary Gelles, Paul Tiede +4
The Event Horizon Telescope (EHT) has produced images of two supermassive black holes, Messier~87* (M 87*) and Sagittarius~A* (Sgr A*). The EHT collaboration used these images to i…
Orbital motion near Sagittarius A* -- Constraints from polarimetric ALMA observations
Maciek Wielgus, Monika Moscibrodzka, Jesse Vos +6
We report on the polarized light curves of the Galactic Center supermassive black hole Sagittarius A*, obtained at millimeter wavelength with the Atacama Large Millimeter/submillim…
Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
Michael Janssen, Heino Falcke, Matthias Kadler +236
Very-long-baseline interferometry (VLBI) observations of active galactic nuclei at millimeter wavelengths have the power to reveal the launching and initial collimation region of e…
The Polarized Image of a Synchrotron Emitting Ring of Gas Orbiting a Black Hole
Ramesh Narayan, Daniel C. M. Palumbo, Michael D. Johnson +237
Synchrotron radiation from hot gas near a black hole results in a polarized image. The image polarization is determined by effects including the orientation of the magnetic field i…
First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon
The Event Horizon Telescope Collaboration
Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. This polarized synchrotr…
Polarized Image of Equatorial Emission in the Kerr Geometry
Zachary Gelles, Elizabeth Himwich, Daniel C. M. Palumbo +1
We develop a simple toy model for polarized images of synchrotron emission from an equatorial source around a Kerr black hole by using a semi-analytic solution of the null geodesic…
The Role of Adaptive Ray Tracing in Analyzing Black Hole Structure
Z. Gelles, B. S. Prather, D. C. M. Palumbo +3
The recent advent of the Event Horizon Telescope (EHT) has made direct imaging of supermassive black holes a reality. Simulated images of black holes produced via general relativis…