Black Holes & Event Horizon Imaging
Event Horizon Telescope images of M87* and Sgr A*, polarization and spin measurements and black-hole ringdown tests.
Most influential
- First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm. This allows u…
Article4,205 citationsarXiv:1906.11238doi:10.3847/2041-8213/ab0ec7 - First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A$^*$), the Galactic center source associated with a supermassive black hole. These observations were conducted in 2017 using a global interferometric array of eight telescopes operating at a wavelength of $λ=1.3\,{\rm mm}$. The EHT data resolve a compact emission region w…
Article1,865 citationsarXiv:2311.08680doi:10.3847/2041-8213/ac6674 - First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
We present measurements of the properties of the central radio source in M87 using Event Horizon Telescope data obtained during the 2017 campaign. We develop and fit geometric crescent models (asymmetric rings with interior brightness depressions) using two independent sampling algorithms that consider distinct representations of the visibility data. We show…
Article1,629 citationsarXiv:1906.11243doi:10.3847/2041-8213/ab1141 - First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ~40 micro-as, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. The ring is persistent across four observing nights a…
Article1,501 citationsarXiv:1906.11241doi:10.3847/2041-8213/ab0e85 - First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Here we consider the physical implications of the asymmetric ring seen in the 2017 EHT data. To this end, we construct a large library of models based on general relativistic magnetohydrodynamic (GRMHD) s…
Article1,427 citationsarXiv:1906.11242doi:10.3847/2041-8213/ab0f43 - Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A ∗
Horizon-scale images of black holes (BHs) and their shadows have opened an unprecedented window onto tests of gravity and fundamental physics in the strong-field regime. We consider a wide range of well-motivated deviations from classical General Relativity (GR) BH solutions, and constrain them using the Event Horizon Telescope (EHT) observations of Sagittar…
Article748 citationsarXiv:2205.07787doi:10.1088/1361-6382/acd97b - First Sagittarius A* Event Horizon Telescope Results. VI. Testing the Black Hole Metric
Astrophysical black holes are expected to be described by the Kerr metric. This is the only stationary, vacuum, axisymmetric metric, without electromagnetic charge, that satisfies Einstein's equations and does not have pathologies outside of the event horizon. We present new constraints on potential deviations from the Kerr prediction based on 2017 EHT obser…
Article672 citationsarXiv:2311.09484doi:10.3847/2041-8213/ac6756 - Black hole shadows, photon rings, and lensing rings
The presence of a bright "photon ring" surrounding a dark "black hole shadow" has been discussed as an important feature of the observational appearance of emission originating near a black hole. We clarify the meaning and relevance of these heuristics with analytic calculations and numerical toy models. The standard usage of the term "shadow" describes the …
Article657 citationsarXiv:1906.00873doi:10.1103/physrevd.100.024018 - First Sagittarius A* Event Horizon Telescope Results. III. Imaging of the Galactic Center Supermassive Black Hole
We present the first event-horizon-scale images and spatiotemporal analysis of Sgr A* taken with the Event Horizon Telescope in 2017 April at a wavelength of 1.3 mm. Imaging of Sgr A* has been conducted through surveys over a wide range of imaging assumptions using the classical CLEAN algorithm, regularized maximum likelihood methods, and a Bayesian posterio…
Article449 citationsarXiv:2311.09479doi:10.3847/2041-8213/ac6429 - Shadows of Kerr Black Holes with Scalar Hair
Using backwards ray tracing, we study the shadows of Kerr black holes with scalar hair (KBHsSH). KBHsSH interpolate continuously between Kerr BHs and boson stars (BSs), so we start by investigating the lensing of light due to BSs. Moving from the weak to the strong gravity region, BSs - which by themselves have no shadows - are classified, according to the l…
Article530 citationsarXiv:1509.00021doi:10.1103/physrevlett.115.211102 - Universal interferometric signatures of a black hole’s photon ring
The Event Horizon Telescope image of the supermassive black hole in the galaxy M87 is dominated by a bright, unresolved ring. General relativity predicts that embedded within this image lies a thin "photon ring," which is composed of an infinite sequence of self-similar subrings that are indexed by the number of photon orbits around the black hole. The subri…
Article410 citationsarXiv:1907.04329doi:10.1126/sciadv.aaz1310 - Constraints on black-hole charges with the 2017 EHT observations of M87*
Our understanding of strong gravity near supermassive compact objects has recently improved thanks to the measurements made by the Event Horizon Telescope (EHT). We use here the M87* shadow size to infer constraints on the physical charges of a large variety of nonrotating or rotating black holes. For example, we show that the quality of the measurements is …
Article344 citationsarXiv:2105.09343doi:10.1103/physrevd.103.104047 - Hunting for extra dimensions in the shadow of M87*
The Event Horizon Telescope has recently provided the first image of the dark shadow around the supermassive black hole M87*. The observation of a highly circular shadow provides strong limits on deviations of M87*'s quadrupole moment from the Kerr value. We show that the absence of such a deviation can be used to constrain the physics of extra dimensions of…
Article364 citationsarXiv:1905.12421doi:10.1103/physrevd.100.024020 - Magnetically charged black holes from non-linear electrodynamics and the Event Horizon Telescope
Non-linear electrodynamics (NLED) theories are well-motivated extensions of QED in the strong field regime, and have long been studied in the search for regular black hole (BH) solutions. We consider two well-studied and well-motivated NLED models coupled to General Relativity: the Euler-Heisenberg model and the Bronnikov model. After carefully accounting fo…
Article337 citationsarXiv:1912.08231doi:10.1088/1475-7516/2020/02/003 - Gravitational Test Beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole
The 2017 Event Horizon Telescope (EHT) observations of the central source in M87 have led to the first measurement of the size of a black-hole shadow. This observation offers a new and clean gravitational test of the black-hole metric in the strong-field regime. We show analytically that spacetimes that deviate from the Kerr metric but satisfy weak-field tes…
Article336 citationsarXiv:2010.01055doi:10.1103/physrevlett.125.141104
Newest work
- Testing Conformal Weyl Gravity with Plasma Modified Black Hole Shadows and EHT ConstraintsPreprintarXiv:2610.36562
- A Collimated Protostellar Outflow Likely Driven by Jet and Reshaped by Environment in the Sagittarius C Cloud of the Central Molecular ZonePreprintarXiv:2610.36573
- Improved constraints on higher-derivative effective field theory extensions of general relativity with GW230627_015337PreprintarXiv:2610.36728
- Self lensing in BH-NS binaries as progenitors for periodically repeating Fast Radio BurstsPreprintarXiv:2610.37052
- Tidal contributions to neutron star orbital precession around Sgr $A^*$PreprintarXiv:2610.35776
- Can a Wormhole Induce a Monopole?PreprintarXiv:2610.35969
- Late Epoch Infrared Spectroscopy and Two-Component 3D Photoionization Modeling of Classical Nova V5668 SgrPreprintarXiv:2610.33376
- Gravitational Waves from Ringing Dyonic Black Holes and Estimation of Parameters in Einstein-Bumblebee-Maxwell GravityPreprintarXiv:2610.33569
- Perturbations and phenomenology of compact objects in quantum gravity theoriesPreprintarXiv:2610.31536
- Image Morphology of Misaligned Magnetically Arrested DisksPreprintarXiv:2610.31754