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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 (…
Joint ALMA/X-ray monitoring of the radio-quiet type 1 AGN IC 4329A
E. Shablovinskaya, C. Ricci, C-S. Chang +20
The origin of a compact millimeter (mm, 100-250 GHz) emission in radio-quiet active galactic nuclei (RQ AGN) remains debated. Recent studies propose a connection with self-absorbed…
XMM-Newton --NuSTAR monitoring campaign of the Seyfert 1 galaxy IC 4329A
A. Tortosa, C. Ricci, E. Shablovinskaia +13
We present the results of a joint {\it XMM-Newton} and {\it NuSTAR} campaign on the active galactic nucleus (AGN) IC 4329A, consisting of 9 20 ks {\it XMM-Newton} observat…
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…
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…
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…
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…
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…
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…
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…
A search for pulsars around Sgr A* in the first Event Horizon Telescope dataset
Pablo Torne, Kuo Liu, Ralph P. Eatough +282
The Event Horizon Telescope (EHT) observed in 2017 the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A*), at a frequency of 228.1 GHz (=1.3 mm). Th…
The Event Horizon Telescope Image of the Quasar NRAO 530
Svetlana Jorstad, Maciek Wielgus, Rocco Lico +27
We report on the observations of the quasar NRAO 530 with the Event Horizon Telescope (EHT) on 2017 April 5-7, when NRAO 530 was used as a calibrator for the EHT observations of Sa…
Extended hard X-ray emission in highly obscured AGN
Jingzhe Ma, Martin Elvis, G. Fabbiano +3
Kilo-parsec scale hard ( 3 keV) X-ray continuum and fluorescent Fe K line emission has been recently discovered in nearby Compton-thick (CT) active galactic nuclei (AGN), whi…
Resolving the inner parsec of the blazar J1924-2914 with the Event Horizon Telescope
Sara Issaoun, Maciek Wielgus, Svetlana Jorstad +27
The blazar J1924-2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic Center's black hole Sagittarius A*. Here we present the first total and linearly polari…
Millimeter light curves of Sagittarius A* observed during the 2017 Event Horizon Telescope campaign
Maciek Wielgus, Nicola Marchili, Ivan Marti-Vidal +28
The Event Horizon Telescope (EHT) observed the compact radio source, Sagittarius A* (Sgr A*), in the Galactic Center on 2017 April 5-11 in the 1.3 millimeter wavelength band. At th…
X-ray Coronal Properties of Swift/BAT-Selected Seyfert 1 Active Galactic Nuclei
Nikita Kamraj, Murray Brightman, Fiona A. Harrison +9
The corona is an integral component of Active Galactic Nuclei (AGN) which produces the bulk of the X-ray emission above 1--2 keV. However, many of its physical properties and the m…
The Variability of the Black-Hole Image in M87 at the Dynamical Time Scale
Kaushik Satapathy, Dimitrios Psaltis, Feryal Ozel +235
The black-hole images obtained with the Event Horizon Telescope (EHT) are expected to be variable at the dynamical timescale near their horizons. For the black hole at the center o…
Extreme Relativistic Reflection in the Active Galaxy ESO 033-G002
D. J. Walton, M. Balokovic, A. C. Fabian +13
We present the first high signal-to-noise broadband X-ray spectrum of the radio-quiet type-2 Seyfert ESO 033-G002, combining data from - and . The nuclear X-ra…
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…
A Highly Accreting Low-Mass Black Hole Hidden in the Dust: Suzaku and NuSTAR observations of the NLS1 Mrk 1239
Jiachen Jiang, Mislav Baloković, Murray Brightman +3
We present torus modelling for the X-ray spectra of a nearby narrow-line Seyfert 1 galaxy Mrk 1239 (), based on archival Suzaku, NuSTAR and Swift observations. Our model…
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…
First M87 Event Horizon Telescope Results. VII. Polarization of the Ring
The Event Horizon Telescope Collaboration
In 2017 April, the Event Horizon Telescope (EHT) observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy. These 1.3 mm wavelength observat…
Properties of the Obscuring Torus in NGC 1052 from Multi-epoch Broadband X-ray Spectroscopy
M. Baloković, S. E. Cabral, L. Brenneman +1
Obscuration of the innermost parts of active galactic nuclei (AGN) is observed in the majority of the population both in the nearby universe and at high redshift. However, the natu…
NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei: II. Median High-energy Cutoff in Seyfert II Hard X-ray Spectra
M. Baloković, F. A. Harrison, G. Madejski +16
Broadband X-ray spectroscopy of the X-ray emission produced in the coronae of active galactic nuclei (AGN) can provide important insights into the physical conditions very close to…