252 citations · 2.8k across the 102 of their papers we have counts for
104 papers
Discovery of minute-scale polarization angle rotation in a supermassive black hole jet
Aristeidis Polychronakis, Ioannis Liodakis, Dmitry Blinov +7
Relativistic jets from supermassive black holes oriented towards our line of sight called blazars have puzzled the astronomical community for decades. Their fast jets and preferent…
A Multiwavelength Study of a Long-Duration VHE Flare from BL Lacertae with VERITAS
Atreya Acharyya, Avery Archer, Priyadarshini Bangale +72
We report the first observations of a long-duration very-high-energy (VHE; GeV) flare from BL Lacertae (VER J2202+422), taken with the Very Energetic Radiation Imaging Te…
WALOP-South: a four camera one shot imaging polarimeter for the PASIPHAE survey. Paper III -- PSF modelling
Indrajit Paul, Kishan Deka, Tuhin Ghosh +22
The two WALOP instruments, built for the PASIPHAE survey, will measure the linear polarization of large numbers of stars in the Galactic polar regions in the SDSS- band. They ar…
Wide Area Linear Optical Polarimeter Control Software
John A. Kypriotakis, Bhushan Joshi, Dmitry Blinov +19
The WALOPControl software is designed to facilitate comprehensive control and operation of the WALOP (Wide Area Linear Optical Polarimeter) polarimeters, ensuring safe and concurre…
IXPE Observations of the Blazar Mrk 501 in 2022: A Multiwavelength View
L. Lisalda, E. Gau, H. Krawczynski +157
The blazar Markarian 501 (Mrk 501) was observed on three occasions over a 4-month period between 2022 March and 2022 July with the Imaging X-ray Polarimetry Explorer (IXPE). In thi…
Exploring Compact Symmetric Objects with Complex Morphologies
E. E. Sheldahl, G. B. Taylor, S. E. Tremblay +9
Compact symmetric objects (CSOs) are a unique class of jetted active galactic nuclei (AGN) defined by sub-kpc radio emission, showing radio structure on both sides of the central e…
Very-high-energy gamma-ray detection and long-term multi-wavelength view of the flaring blazar B2 1811+31
K. Abe, S. Abe, J. Abhir +231
Among the blazars whose emission has been detected up to very-high-energy (VHE; 100 GeV < E < 100 TeV) gamma rays, intermediate synchrotron-peaked BL Lacs (IBLs) are quite rare. Th…
Characterizing Candidate Blazar Counterparts of the Ultra-High-Energy Event KM3-230213A
KM3NeT Collaboration, MessMapp Group, LAT Collaboration +13
High-energy astrophysical neutrinos serve as crucial messengers for understanding hadronic acceleration processes and identifying the origins of cosmic rays, with blazars among the…
Time-dependent modelling of short-term variability in the TeV-blazar VER J0521+211 during the major flare in 2020
MAGIC Collaboration, S. Abe, J. Abhir +228
The BL Lacertae object VER J0521+211 underwent a notable flaring episode in February 2020. A short-term monitoring campaign, led by the MAGIC (Major Atmospheric Gamma Imaging Chere…
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…
The WALOP-North Instrument I: Optical Design, Filter Design, Calibration
John A. Kypriotakis, Siddharth Maharana, Ramya M. Anche +18
The Wide Area Linear Optical Polarimeter North (WALOP-North) is an optical polarimeter designed for the needs of the PASIPHAE survey. It will be installed on the 1.3m telescope at…
Multi-wavelength study of OT 081: broadband modelling of a transitional blazar
MAGIC Collaboration, H. Abe, S. Abe +270
OT 081 is a well-known, luminous blazar that is remarkably variable in many energy bands. We present the first broadband study of the source which includes very-high-energy (VHE, $…
IXPE Observation of the Low-Synchrotron Peaked Blazar S4 0954+65 During An Optical-X-ray Flare
Pouya M. Kouch, Ioannis Liodakis, Francesco Fenu +134
The X-ray polarization observations made possible with the Imaging X-ray Polarimetry Explorer (IXPE) offer new ways of probing high-energy emission processes in astrophysical jets…
A wiggling filamentary jet at the origin of the blazar multi-wavelength behaviour
C. M. Raiteri, M. Villata, M. I. Carnerero +96
Blazars are beamed active galactic nuclei known for their strong multi-wavelength variability on timescales from years down to minutes. We aim to investigate the suitability of the…
A Two-Week Monitoring Campaign on Mrk 421
W. Peter Maksym, Ioannis Liodakis, M. Lynne Saade +153
X-ray polarization is a unique new probe of the particle acceleration in astrophysical jets made possible through the Imaging X-ray Polarimetry Explorer. Here we report on the firs…
Insights from the first flaring activity of a high-synchrotron-peaked blazar with X-ray polarization and VHE gamma rays
MAGIC Collaboration, K. Abe, S. Abe +250
We study a flaring activity of the HSP Mrk421 that was characterized from radio to very-high-energy (VHE; E TeV) gamma rays with MAGIC, Fermi-LAT, Swift, XMM-Newton and sever…
The Radio Spectra of High Luminosity Compact Symmetric Objects (CSO-2s): Implications for Studies of Compact Jetted Active Galactic Nuclei
P. V. de la Parra, A. C. S Readhead, T. Herbig +18
This paper addresses, for the first time, a key aspect of the phenomenology of Compact Symmetric Objects (CSOs) -- the characteristics of their radio spectra. We present a radio-sp…
PKS~J08050111: A Second Owens Valley Radio Observatory Blazar Showing Highly Significant Sinusoidal Radio Variability -- The Tip of the Iceberg
P. V. de la Parra, S. Kiehlmann, P. Mroz +23
Owens Valley Radio Observatory (OVRO) observations of supermassive black hole binary (SMBHB) candidate PKS~2131021 revealed, for the first time, six likely characteristics of th…
Association of the IceCube neutrinos with blazars in the CGRaBS sample
Pouya M. Kouch, Elina Lindfors, Talvikki Hovatta +11
The origin of high-energy (HE) astrophysical neutrinos has remained an elusive hot topic in the field of HE astrophysics for the past decade. Apart from a handful of individual ass…
PKS 2131-021 -- Discovery of Strong Coherent Sinusoidal Variations from Radio to Optical Frequencies: Compelling Evidence for a Blazar Supermassive Black Hole Binary
S. Kiehlmann, P. V. de la Parra, A. G. Sullivan +31
Haystack and Owens Valley Radio Observatory (OVRO) observations recently revealed strong, intermittent, sinusoidal total flux-density variations that maintained coherence between 1…
Systems design, assembly, integration and lab testing of WALOP-South Polarimeter
Siddharth Maharana, A. N. Ramaprakash, Chaitanya Rajarshi +28
Wide-Area Linear Optical Polarimeter (WALOP)-South is the first wide-field and survey-capacity polarimeter in the optical wavelengths. On schedule for commissioning in 2024, it wil…
Testing particle acceleration in blazar jets with continuous high-cadence optical polarization observations
Ioannis Liodakis, Sebastian Kiehlmann, Alan P. Marscher +44
Variability can be the pathway to understanding the physical processes in astrophysical jets, however, the high-cadence observations required to test particle acceleration models a…
A -Ray Emitting Blazar at Redshift 3.64: Fermi-LAT and OVRO Observations of PKS 0201+113
Hai Lei, Ying-Kang Zhang, Xiong Jiang +5
High-redshift () -ray blazars are rare, but they are crucial for our understanding of jet evolution, -ray production and propagation, and the growth of supermassive bla…
The first degree-scale starlight-polarization-based tomography map of the magnetized interstellar medium
V. Pelgrims, N. Mandarakas, R. Skalidis +21
We present the first degree-scale tomography map of the dusty magnetized interstellar medium (ISM) from stellar polarimetry and distance measurements. We used the RoboPol polarimet…