173 citations · 611 across the 25 of their papers we have counts for
27 papers
Optical polarimetry of the accreting black hole X-ray binary Swift J1727.81613 over the state transition and radio ejections
Anagha P. Nitindala, Alexandra Veledina, Vadim Kravtsov +7
We present the first optical () polarimetric observations of Swift J1727.81613 during its 2023--2024 outburst. Observations were performed during the X-ray hard-to-soft sta…
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…
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…
Variability of X-ray polarization of Cyg X-1
Vadim Kravtsov, Anastasiia Bocharova, Alexandra Veledina +31
We present the results of a three-year X-ray, optical, and radio polarimetric monitoring campaign of the prototypical black hole X-ray binary Cyg X-1, conducted from 2022 to 2024.…
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…
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…
Neutrino beaming in ultraluminous X-ray pulsars as a result of gravitational lensing by neutron stars
Alexander A. Mushtukov, Alexander Y. Potekhin, Ivan D. Markozov +6
X-ray pulsars experiencing extreme mass accretion rates can produce neutrino emission in the MeV energy band. Neutrinos in these systems are emitted in close proximity to the stell…
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…
An IXPE-Led X-ray Spectro-Polarimetric Campaign on the Soft State of Cygnus X-1: X-ray Polarimetric Evidence for Strong Gravitational Lensing
James F. Steiner, Edward Nathan, Kun Hu +134
We present the first X-ray spectropolarimetric results for Cygnus X-1 in its soft state from a campaign of five IXPE observations conducted during 2023 May-June. Companion multiwav…
Studying geometry of the ultraluminous X-ray pulsar Swift J0243.6+6124 using X-ray and optical polarimetry
Juri Poutanen, Sergey S. Tsygankov, Victor Doroshenko +108
Discovery of pulsations from a number of ULXs proved that accretion onto neutron stars can produce luminosities exceeding the Eddington limit by several orders of magnitude. The co…
Recovery of the X-ray polarisation of Swift J1727.81613 after the soft-to-hard spectral transition
J. Podgorný, J. Svoboda, M. Dovčiak +34
We report on the detection of X-ray polarisation in the black-hole X-ray binary Swift J1727.81613 during its dim hard spectral state by the Imaging X-ray Polarimetry Explorer (I…
Orbital variability of polarized X-ray radiation reflected from a companion star in X-ray binaries
Varpu Ahlberg, Vadim Kravtsov, Juri Poutanen
The reflection of X-ray radiation produced near a compact object from its stellar companion contributes to the orbital variability of polarization in X-ray binaries. The X-rays are…
X-ray Polarimetry as a Tool to Constrain Orbital Parameters in X-Ray Binaries
John Rankin, Vadim Kravtsov, Fabio Muleri +10
X-ray binary systems consist of a companion star and a compact object in close orbit. Thanks to their copious X-ray emission, these objects have been studied in detail using X-ray…
X-Ray Polarized View on the Accretion Geometry in the X-Ray Binary Circinus X-1
John Rankin, Fabio La Monaca, Alessandro Di Marco +101
Cir X-1 is a neutron star X-ray binary characterized by strong variations in flux during its eccentric 16.6 days orbit. There are also strong variations in the spectral state…
Tracking the X-ray Polarization of the Black Hole Transient Swift J1727.8-1613 during a State Transition
Adam Ingram, Niek Bollemeijer, Alexandra Veledina +120
We report on an observational campaign on the bright black hole X-ray binary Swift J1727.81613 centered around five observations by the Imaging X-ray Polarimetry Explorer (IXPE)…
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…
Discovery of X-ray Polarization from the Black Hole Transient Swift J1727.8-1613
Alexandra Veledina, Fabio Muleri, Michal Dovciak +113
We report the first detection of the X-ray polarization of the bright transient Swift J1727.8-1613 with the Imaging X-ray Polarimetry Explorer. The observation was performed at the…
Complex variations of X-ray polarization in the X-ray pulsar LS V +44 17/RX J0440.9+4431
Victor Doroshenko, Juri Poutanen, Jeremy Heyl +109
We report on Imaging X-ray polarimetry explorer (IXPE) observations of the Be-transient X-ray pulsar LS V +44 17/RX J0440.9+4431 made at two luminosity levels during the giant outb…
Peering into the tilted heart of Cyg X-1 with high-precision optical polarimetry
Vadim Kravtsov, Alexandra Veledina, Andrei V. Berdyugin +7
We present the high-precision optical polarimetric observations of black hole X-ray binary Cyg X-1, spanning several cycles of its 5.6 day orbital period. Week-long observations on…
X-ray Polarization Observations of BL Lacertae
Riccardo Middei, Ioannis Liodakis, Matteo Perri +143
Blazars are a class of jet-dominated active galactic nuclei with a typical double-humped spectral energy distribution. It is of common consensus the Synchrotron emission to be resp…
Polarized Blazar X-rays imply particle acceleration in shocks
Ioannis Liodakis, Alan P. Marscher, Iván Agudo +125
Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to $\sim 1…
Polarized x-rays constrain the disk-jet geometry in the black hole x-ray binary Cygnus X-1
Henric Krawczynski, Fabio Muleri, Michal Dovčiak +111
A black hole x-ray binary (XRB) system forms when gas is stripped from a normal star and accretes onto a black hole, which heats the gas sufficiently to emit x-rays. We report a po…
Optical polarization signatures of black hole X-ray binaries
Vadim Kravtsov, Andrei V. Berdyugin, Ilia A. Kosenkov +7
Polarimetry provides an avenue for probing the geometry and physical mechanisms producing optical radiation in many astrophysical objects, including stellar binary systems. We pres…
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…