884 citations · 1.7k across the 23 of their papers we have counts for
24 papers
Constraints on the Intranight Optical Variability of Intermediate-Mass Black Hole Candidates
Wenwen Zuo, Hengxiao Guo, Wanling Liu +12
Intermediate-mass black holes (IMBHs) provide a unique regime for studying accretion variability at the low-mass end of the black hole population, yet their intranight optical vari…
The Intermediate-Mass Black Hole Reverberation Mapping Project: Scientific Overview and Sample Characteristics
Hengxiao Guo, Jiancheng Wu, Wenwen Zuo +38
Recent discoveries with the James Webb Space Telescope of massive black holes at high redshift have highlighted fundamental questions about black hole seed formation and the coevol…
Empirical Near-Infrared Spectral Templates from SPHEREx: Disentangling AGN and Host-Galaxy Emission
Wenke Ren, Hengxiao Guo, Zhenya Zheng +9
SPHEREx conducts the first all-sky near-infrared spectral survey over 0.75-5.0 m, spanning the transition from host-galaxy starlight to AGN-heated torus emission and enabling sp…
Magnetically Arrested Discs Powering Jets in a Large Sample of Low-Accretion FR I Radio Galaxies
Huibo Fei, Han He, Bei You +4
We study a sample of 289 Fanaroff-Riley type I (FR I) radio galaxies selected from the LOFAR Two-Metre Sky Survey (LoTSS) DR1, identified by their edge-darkened radio morphologies.…
Multi-band optical photometric variability of the blazar OJ 287 from 2015 to 2025
Alok C. Gupta, Karan Dogra, Mark Kidger +101
We present the most densely sampled multi-band optical photometric observations of the peculiar BL Lacertae object OJ 287 from 2015 to 2025 with a focus on its optical activity on…
Shigatse Astronomical Site Testing. I. Cloud-cover Climatology and Selected Local Meteorological Conditions
Baiyu Zhang, Hejun Yang, Xiaojun Dong +15
As the first paper in a Shigatse astronomical site-testing series, we present a multi-source assessment of cloud cover and selected local meteorological conditions at the Shigatse…
Identifying the secondary jet in the RadioAstron image of OJ~287
Mauri J. Valtonen, Lankeswar Dey, Staszek Zola +26
The 136 year long optical light curve of OJ~287 is explained by a binary black hole model where the secondary is in a 12 year orbit around the primary. Impacts of the secondary on…
From Equipartition to Curvature: The Spectral Evolution of 4FGL Blazars
Muhammad S. Anjum, Shu-Jin Hou, Liang Chen +2
We investigate the evolution of spectral energy distribution (SED) and underlying electron energy distribution (EED) by modeling the nearly simultaneous broadband spectra of select…
Lunar Orbital VLBI Experiment: motivation, scientific purposes and status
Xiaoyu Hong, Weiren Wu, Qinghui Liu +47
The Lunar Orbital VLBI Experiment (LOVEX) is a scientific component of the Chinese Lunar Exploration Project (CLEP) Chang'E-7. The spaceborne component of LOVEX is implemented onbo…
The Intermediate-Mass Black Hole Reverberation Mapping Project: First Detection of Mid-Infrared Lags in Prototypical IMBHs in NGC 4395 and POX 52
Jingbo Sun, Hengxiao Guo, Wenwen Zuo +25
The search for robust evidence of intermediate-mass black holes (IMBHs) is crucial for understanding black hole seeding process and the formation of supermassive black holes in the…
Constraints on the fractional changes of the fundamental constants at a look-back time of 2.5 Myrs
Renzhi Su, Tao An, Stephen J. Curran +3
The quantum nature of gravity remains one of the greatest mysteries of modern physics, with many unified theories predicting variations in fundamental constants across space and ti…
Multiband Optical Variability of the Blazar 3C 454.3 on Diverse Timescales
Karan Dogra, Alok C. Gupta, C. M. Raiteri +79
Due to its peculiar and highly variable nature, the blazar 3C 454.3 has been extensively monitored by the WEBT team. Here, we present for the first time these long-term optical flu…
Spectral Energy Distribution Variability of the Blazar OJ 287 during 2009-2021
Wenwen Zuo, Alok C. Gupta, Minfeng Gu +11
Using nearly simultaneous radio, near-infrared, optical, and ultraviolet data collected since 2009, we constructed 106 spectral energy distributions (SEDs) of the blazar OJ 287. Th…
X-ray Flux and Spectral Variability of the Blazar OJ 287 with Suzaku
Dongtao Zhou, Zhongli Zhang, Alok C. Gupta +4
We present analyses of Suzaku XIS light curves and spectra of the BL Lac object OJ 287 with observations positioned primarily around proposed recurrent optical outbursts. The first…
Evidence of jet activity from the secondary black hole in the OJ287 binary system
Mauri J. Valtonen, Staszek Zola, Alok C. Gupta +29
We report the study of a huge optical intraday flare on November 12, 2021, at 2 am UT, in the blazar OJ287. In the binary black hole model it is associated with an impact of the se…
Reverberation evidence for Stream Collision and Delayed Disk Formation in Tidal Disruption Events
Hengxiao Guo, Jingbo Sun, Shuang-Liang Li +9
When a star passes through the tidal disruption radius of a massive black hole (BH), it can be torn apart by the tidal force of the BH, known as the Tidal Disruption Event (TDE). S…
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…
Optical intra-day variability of the blazar S5 0716+714
Tushar Tripathi, Alok C. Gupta, Ali Takey +18
We present an extensive recent multi-band optical photometric observations of the blazar S5 0716+714 carried out over 53 nights with two telescopes in India, two in Bulgaria, one i…
Multi-wavelength temporal variability of the blazar PKS 1510-089
Q. Yuan, Pankaj Kushwaha, Alok C. Gupta +13
We perform correlation and periodicity search analyses on long-term multi-band light curves of the FSRQ 1510-089 observed by the space-based Fermi--Large Area Telescope in gamma-ra…
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. III. Data Processing and Calibration
The Event Horizon Telescope Collaboration
We present the calibration and reduction of Event Horizon Telescope (EHT) 1.3mm radio wavelength observations of the supermassive black hole candidate at the center of the radio ga…
Core shift effect in blazars
A. Agarwal, P. Mohan, Alok C. Gupta +8
We studied the pc-scale core shift effect using radio light curves for three blazars, S5 0716+714, 3C 279 and BL Lacertae, which were monitored at five frequencies () between 4.…
Optical-NIR variability of blazars on diverse timescales
A. Agarwal, A. C. Gupta
To search for optical variability on a wide range of timescales, we have carried out photometric monitoring of 3C 454.3, 3C 279 and S5 0716+714. CCD magnitudes in B, V, R and I pas…
Multi-band optical-NIR variability of blazars on diverse timescales
Aditi Agarwal, Alok C. Gupta, R. Bachev +10
To search for optical variability on a wide range of timescales, we have carried out photometric monitoring of two flat spectrum radio quasars, 3C 454.3 and 3C 279, plus one BL Lac…