199 citations · 1.1k across the 47 of their papers we have counts for
35 papers · 1 filter
POLAMI Multi-Wavelength Polarization Study of AGN Jets: A Millimeter-Optical Comparison
C. Casadio, D. Blinov, I. Agudo +20
Millimeter-band polarimetry offers a powerful probe of AGN jets, accessing regions less affected by opacity and Faraday rotation than at longer radio wavelengths. As part of the PO…
First detection of VHE gamma-ray signal from the FSRQ TON 0599
MAGIC Collaboration, K. Abe, S. Abe +245
TON\,0599 (z=0.7247) belongs to the few flat spectrum radio quasars (FSRQs) detected in the very high energy (VHE, \,GeV) gamma-ray band. Its redshift makes it currently o…
Unveiling blazar synchrotron emission: a multiwavelength polarimetric study of HSP and LSP populations
Sara Capecchiacci, Ioannis Liodakis, Riccardo Middei +96
Polarimetric properties of blazars allow us to put constraints on the acceleration mechanisms that fuel their powerful jets. By studying the multiwavelength polarimetric behaviour…
Determining the origin of the X-ray emission in blazars through multiwavelength polarization
Ioannis Liodakis, Haocheng Zhang, Stella Boula +48
The origin of the high-energy emission in astrophysical jets from black holes is a highly debated issue. This is particularly true for jets from supermassive black holes that are a…
High optical to X-ray polarization ratio reveals Compton scattering in BL Lacertae's jet
Ivan Agudo, Ioannis Liodakis, Jorge Otero-Santos +147
Blazars, supermassive black hole systems (SMBHs) with highly relativistic jets aligned with the line of sight, are the most powerful long-lived emitters of electromagnetic emission…
The polarisation behaviour of OJ 287 viewed through radio, millimetre and optical observations between 2015 and 2017
J. Jormanainen, T. Hovatta, E. Lindfors +13
OJ 287 is a bright blazar with century-long observations, and one of the strongest candidates to host a supermassive black hole binary. Its polarisation behaviour between 2015 and…
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, $…
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…
Optical and near-infrared polarization of the black hole X-ray binary A0620-00 in quiescence
Vadim Kravtsov, Alexandra Veledina, Andrei V. Berdyugin +12
We present simultaneous high-precision optical polarimetric and near-infrared (NIR) to ultraviolet (UV) photometric observations of low-mass black hole X-ray binary A0620-00 in the…
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…
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…
Distinguishing radiation mechanisms and particle populations in blazar jets through long-term multi-band monitoring with RINGO3 and Fermi
Callum McCall, Helen Jermak, Iain A. Steele +6
We present the results of seven years of multicolour photometric monitoring of a sample of 31 -ray bright blazars using the RINGO3 polarimeter on the Liverpool Telescope from 20…
The extreme coronal line emitter AT 2022fpx: Varying optical polarization properties and late-time X-ray flare
Karri I. I. Koljonen, Ioannis Liodakis, Elina Lindfors +8
Supermassive black holes disrupt passing stars, producing outbursts called tidal disruption events (TDEs). TDEs have recently gained attention due to their unique dynamics and emis…
Detection of an intranight optical hard-lag with colour variability in blazar PKS 0735+178
Callum McCall, Helen E. Jermak, Iain A. Steele +3
Blazars are a highly variable subclass of active galactic nuclei that have been observed to vary significantly during a single night. This intranight variability remains a debated…
GRB 210619B: first gamma-ray burst detection by the novel polarimeter MOPTOP
M. Shrestha, I. A. Steele, S. Kobayashi +4
GRB~210619B was a bright long gamma-ray burst (GRB) which was optically followed up by the novel polarimeter MOPTOP on the Liverpool Telescope (LT). This was the first GRB detectio…
Refining the prediction for OJ 287 next impact flare arrival epoch
Mauri J. Valtonen, Staszek Zola, A. Gopakumar +23
The bright blazar OJ~287 routinely parades high brightness bremsstrahlung flares which are explained as being a result of a secondary supermassive black hole (SMBH) impacting the a…
Polarimetry and Photometry of Gamma-Ray Bursts Afterglows with RINGO3
M. Shrestha, I. A. Steele, S. Kobayashi +7
We present photometric and polarimetric measurements of gamma-ray burst (GRB) optical afterglows observed by the RINGO3 imaging polarimeter over its 7 year lifetime mounted o…
Multiwavelength astrophysics of the blazar OJ 287 and the project MOMO
S. Komossa, A. Kraus, D. Grupe +19
We are carrying out the densest and longest multiyear, multiwavelength monitoring project of OJ 287 ever done. The project MOMO (Multiwavelength Observations and Modelling of OJ 28…
Promise of persistent multi-messenger astronomy with the blazar OJ 287
Mauri J. Valtonen, Lankeswar Dey, A. Gopakumar +7
Successful observations of the seven predicted bremsstrahlung flares from the unique bright blazar OJ 287 firmly point to the presence of a nanohertz gravitational wave (GW) emitti…
GRB 191016A: A highly collimated gamma-ray burst jet with magnetised energy injection
M. Shrestha, I. A. Steele, S. Kobayashi +7
Long gamma-ray burst GRB 191016A was a bright and slow rising burst that was detected by the \textit{Swift} satellite and followed up by ground based Liverpool Telescope (LT). LT f…
Black hole spin-orbit misalignment in the X-ray binary MAXI J1820+070
Juri Poutanen, Alexandra Veledina, Andrei V. Berdyugin +10
The observational signatures of black holes in x-ray binary systems depend on their masses, spins, accretion rate and the misalignment angle between the black hole spin and the orb…
Spitzer Observations of the Predicted Eddington Flare from Blazar OJ 287
Seppo Laine, Lankeswar Dey, Mauri Valtonen +25
Binary black hole (BH) central engine description for the unique blazar OJ 287 predicted that the next secondary BH impact-induced bremsstrahlung flare should peak on 2019 July 31.…
Monitoring of the radio galaxy M87 during a low emission state from 2012 to 2015 with MAGIC
MAGIC Collaboration, V. A. Acciari, S. Ansoldi +188
M87 is one of the closest (z=0.00436) extragalactic sources emitting at very-high-energies (VHE, E > 100 GeV). The aim of this work is to locate the region of the VHE gamma-ray emi…