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20072026
most citedFirst Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way

1.9k citations · 13.4k across the 79 of their papers we have counts for

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astro-ph.HE2026

Broadband multiwavelength properties of the archetypal blazar 3C 279 during the 2017 Event Horizon Telescope campaign

G. Principe, J. C. Algaba, E. Aviano +529

The archetypal blazar 3C 279 hosts a prominent relativistic jet and exhibits strong broadband variability across the electromagnetic spectrum. In April 2017, the Event Horizon Tele…

astro-ph.HE2026★ 1 cited

Locating the missing large-scale emission in the jet of M87* with short EHT baselines

Boris Georgiev, Paul Tiede, Sebastiano D. von Fellenberg +280

In Very-Long Baseline Interferometric arrays, nearly co-located stations probe the largest scales and typically cannot resolve the observed source. In the absence of large-scale st…

astro-ph.HE2026

A long-term multiwavelength study of the flat spectrum radio quasar OP 313

Chiara Bartolini, Elina Lindfors, Andrea Tramacere +25

The Flat Spectrum Radio Quasar OP 313 is a high-redshift (z = 0.997) blazar that entered an intense gamma-ray active phase from November 2023 to March 2024, as observed by the Larg…

astro-ph.HE2026★ 1 cited

Ring Asymmetry and Spin in M87*

Vadim Bernshteyn, Nicholas S. Conroy, Michi Bauböck +263

Event Horizon Telescope (EHT) images of the supermassive black hole M87* depict an asymmetric ring of emission. General relativistic magnetohydrodynamic (GRMHD) models of M87* and…

astro-ph.HE2025★ 4 cited

Probing jet base emission of M87* with the 2021 Event Horizon Telescope observations

Saurabh, Hendrik Müller, Sebastiano D. von Fellenberg +282

We investigate the presence and spatial characteristics of the jet base emission in M87* at 230 GHz, enabled by the enhanced uv coverage in the 2021 Event Horizon Telescope (EHT) o…

astro-ph.HE2025

First Mid-infrared Detection and Modeling of a Flare from Sgr A*. II. Mid-IR Spectral Energy Distribution and Millimeter Polarimetry

Joseph M. Michail, Sebastiano D. von Fellenberg, Garrett K. Keating +20

S. D. von Fellenberg et al. (2025a, Paper I) reported the first mid-infrared detection of a flare from Sgr A*. The JWST/MIRI/MRS observations were consistent with an orbiting hotsp…

astro-ph.HE2025

The First Radio-Bright Off-Nuclear TDE 2024tvd Reveals the Fastest-Evolving Double-Peaked Radio Emission

Itai Sfaradi, Raffaella Margutti, Ryan Chornock +34

We present the first multi-epoch broadband radio and millimeter monitoring of an off-nuclear TDE using the VLA, ALMA, ATA, AMI-LA, and the SMA. The off-nuclear TDE 2024tvd exhibits…

astro-ph.HE2025

Continued Rapid Radio Brightening of the Tidal Disruption Event AT2018hyz

Yvette Cendes, Edo Berger, Paz Beniamini +15

We present ongoing radio observations of the tidal disruption event (TDE) AT2018hyz, which was first detected in the radio at 972 days after disruption, following multiple non-dete…

astro-ph.HE2025★ 4 cited

Origin of the ring ellipticity in the black hole images of M87*

Rohan Dahale, Ilje Cho, Kotaro Moriyama +273

We investigate the origin of the elliptical ring structure observed in the images of the supermassive black hole M87*, aiming to disentangle contributions from gravitational, astro…

astro-ph.HE2025★ 10 cited

The putative center in NGC 1052

Anne-Kathrin Baczko, Matthias Kadler, Eduardo Ros +284

Many active galaxies harbor powerful relativistic jets, however, the detailed mechanisms of their formation and acceleration remain poorly understood. To investigate the area of je…

astro-ph.HE2025★ 13 cited

A multi-frequency study of sub-parsec jets with the Event Horizon Telescope

Jan Röder, Maciek Wielgus, Andrei P. Lobanov +287

The 2017 observing campaign of the Event Horizon Telescope (EHT) delivered the first very long baseline interferometry (VLBI) images at the observing frequency of 230 GHz, leading…

astro-ph.HE2024★ 35 cited

IXPE observation of PKS 2155-304 reveals the most highly polarized blazar

Pouya M. Kouch, Ioannis Liodakis, Riccardo Middei +133

We report the X-ray polarization properties of the high-synchrotron-peaked (HSP) blazar PKS 2155304 based on observations with the Imaging X-ray Polarimetry Explorer (IXPE). We…

astro-ph.HE2024★ 4 cited

The flaring activity of blazar AO 0235+164 during year 2021

Juan Escudero Pedrosa, Iván Agudo, Till Moritz +16

Context. The blazar AO 0235+164, located at redshift , has displayed interesting and repeating flaring activity in the past, the latest episodes occurring in 2008 and 2015.…

astro-ph.HE2024★ 34 cited

Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode

J. C. Algaba, M. Balokovic, S. Chandra +738

The nearby elliptical galaxy M87 contains one of the only two supermassive black holes whose emission surrounding the event horizon has been imaged by the Event Horizon Telescope (…

astro-ph.HE2023★ 93 cited

First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization

The Event Horizon Telescope Collaboration

Event Horizon Telescope (EHT) observations have revealed a bright ring of emission around the supermassive black hole at the center of the M87 galaxy. EHT images in linear polariza…

astro-ph.HE2023★ 12 cited

Polarimetric Geometric Modeling for mm-VLBI Observations of Black Holes

Freek Roelofs, Michael D. Johnson, Andrew Chael +4

The Event Horizon Telescope (EHT) is a millimeter very long baseline interferometry (VLBI) array that has imaged the apparent shadows of the supermassive black holes M87* and Sagit…

astro-ph.HE2023★ 681 cited

First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric

The Event Horizon Telescope Collaboration

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…

astro-ph.HE2023★ 450 cited

First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole

The Event Horizon Telescope Collaboration

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…

astro-ph.HE2023★ 548 cited

First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole

The Event Horizon Telescope Collaboration

In this paper, we provide a first physical interpretation for the Event Horizon Telescope (EHT)'s 2017 observations of Sgr A*. Our main approach is to compare resolved EHT data at…

astro-ph.HE2023★ 1.9k cited

First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way

The Event Horizon Telescope Collaboration

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 observati…

astro-ph.HE2023★ 370 cited

First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass

The Event Horizon Telescope Collaboration

In this paper we quantify the temporal variability and image morphology of the horizon-scale emission from Sgr A*, as observed by the EHT in 2017 April at a wavelength of 1.3 mm. W…

astro-ph.HE2023★ 2 cited

Observations of Low and Intermediate Spectral Peak Blazars with the Imaging X-ray Polarimetry Explorer

Herman L. Marshall, Ioannis Liodakis, Alan P. Marscher +145

We present X-ray polarimetry observations from the Imaging X-ray Polarimetry Explorer (IXPE) of three low spectral peak and one intermediate spectral peak blazars, namely 3C 273, 3…

astro-ph.HE2023★ 43 cited

Magnetic Field Properties inside the Jet of Mrk 421: Multiwavelength Polarimetry Including the Imaging X-ray Polarimetry Explorer

Dawoon E. Kim, Laura Di Gesu, Ioannis Liodakis +133

We conducted a polarimetry campaign from radio to X-ray wavelengths of the high-synchrotron-peak (HSP) blazar Mrk 421, including Imaging X-ray Polarimetry Explorer (IXPE) measureme…

astro-ph.HE2023★ 1 cited

X-ray Polarization of the BL Lac Type Blazar 1ES 0229+200

Steven R. Ehlert, Ioannis Liodakis, Riccardo Middei +110

We present polarization measurements in the band from blazar 1ES 0229+200, the first extreme high synchrotron peaked source to be observed by the Imag…