activity
20232026
most citedX-ray Polarization of BL Lacertae in Outburst

45 citations · 157 across the 21 of their papers we have counts for

collaborators

21 papers

astro-ph.IM2026

Verification of the Polarimetric Capability of the East Asia VLBI Network

Yunjeong Lee, Jongho Park, Do-Young Byun +10

The East Asia VLBI Network (EAVN) has recently enabled dual-polarization observations at and . We present the first systematic verification of its polarimetr…

astro-ph.HE2026

Where within the 3C 84 jet are -rays produced?

Georgios F. Paraschos, Ioannis Liodakis, Svetlana Jorstad +49

The location of -ray creation and emission within extra-galactic jets is a matter of active debate. One particularly well-suited source to pinpoint the location is the nearby, b…

astro-ph.GA2026

Jet-torus interaction revealed by sub-parsec SO absorption in NGC 1052

Satoko Sawada-Satoh, Seiji Kameno, Nozomu Kawakatsu +10

We report the first λ2-mm very long baseline interferometry (VLBI) observations of the radio galaxy NGC 1052, conducted with the Korean VLBI Network (KVN) using a wide-band recordi…

astro-ph.HE2025

The IXPE and multifrequency polarimetric view of the extreme blazars 1ES 1101-232 and RGB J0710+591

Fabrizio Tavecchio, Dawoon E. Kim, Gabriel Emery +53

Multiwavelength polarimetry is a powerful tool to probe magnetic field and flow geometries in the relativistic jets of blazars. In this respect, particularly interesting are the so…

astro-ph.HE2025

Detection of Compton scattering in the jet of 3C 84

Ioannis Liodakis, Sudip Chakraborty, Frédéric Marin +77

3C 84 is the brightest cluster galaxy in the Perseus Cluster. It is among the closest radio-loud active galaxies and among the very few that can be detected from low frequency radi…

astro-ph.GA2025

The variability angular diameter distance and the intrinsic brightness temperature of active galactic nuclei

Whee Yeon Cheong, Sang-Sung Lee, Chanwoo Song +5

Context. It has recently been suggested that angular diameter distances derived from comparing the variability timescales of blazars to angular size measurements with very long bas…

astro-ph.HE2025

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…

astro-ph.HE2025★ 9 cited

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…

astro-ph.HE2025★ 15 cited

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…

astro-ph.GA2025

Polarization flare of 3C 454.3 in millimeter wavelengths seen from decadal polarimetric observations

Hyeon-Woo Jeong, Sang-Sung Lee, Sincheol Kang +6

This study investigates polarimetric characteristics of the blazar 3C~454.3 at 22-129~GHz using decadal~(2011-2022) data sets. In addition, we also delve into the origin of the pol…

astro-ph.HE2025★ 1 cited

Gamma-ray flares from the jet of the blazar CTA 102 in 2016-2018

Sanghyun Kim, Sang-Sung Lee, Juan Carlos Algaba +16

CTA 102 is a -ray bright blazar that exhibited multiple flares in observations by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope during the period of 2016…

astro-ph.HE2024

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…

astro-ph.HE2024

X-ray and multiwavelength polarization of Mrk 501 from 2022 to 2023

Chien-Ting J. Chen, Ioannis Liodakis, Riccardo Middei +143

We present multiwavelength polarization measurements of the luminous blazar Mrk~501 over a 14-month period. The 2--8 keV X-ray polarization was measured with the Imaging X-ray Pola…

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

A study of the radio spectrum of Mrk 421

Jee Won Lee, Sang-Sung Lee, Jeffrey Hodgson +5

We present the results of a spectral analysis using simultaneous multifrequency (22, 43, 86, and 129 GHz) very long baseline interferometry (VLBI) observations of the Korean VLBI N…

astro-ph.HE2023

A Near Magnetic-to-kinetic Energy Equipartition Flare from the Relativistic Jet in AO 0235+164 during 2013-2019

Whee Yeon Cheong, Sang-Sung Lee, Sang-Hyun Kim +17

We present the multiwavelength flaring activity of the blazar AO 0235+164 during its recent active period from 2013 to 2019. From a discrete correlation function (DCF) analysis, we…

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

IXPE and multi-wavelength observations of blazar PG 1553+113 reveal an orphan optical polarization swing

Riccardo Middei, Matteo Perri, Simonetta Puccetti +119

The lower energy peak of the spectral energy distribution of blazars has commonly been ascribed to synchrotron radiation from relativistic particles in the jets. Despite the consen…

astro-ph.HE2023★ 6 cited

Double SSA Spectrum and Magnetic Field Strength of the FSRQ 3C 454.3

Hyeon-Woo Jeong, Sang-Sung Lee, Whee Yeon Cheong +7

We present the results of a radio multi-frequency () study of the blazar 3C~454.3. After subtracting the quiescent spectrum corresponding to optically thin emission,…

astro-ph.HE2023★ 45 cited

X-ray Polarization of BL Lacertae in Outburst

Abel L. Peirson, Michela Negro, Ioannis Liodakis +128

We report the first confidence detection of X-ray polarization in BL Lacertae. During a recent X-ray/-ray outburst, a 287 ksec observation (2022 November 27-30) was tak…