173 citations · 648 across the 31 of their papers we have counts for
35 papers
Breaking the symmetry: X-ray polarization from a spreading layer on a tilted weakly magnetized neutron star
Anna Bobrikova, Alexandra Veledina, Juri Poutanen +1
When modeling the emission from an X-ray binary system, we often assume that the rotational axis of the compact object is aligned with that of the binary system. While often consid…
Peering through the dip: IXPE unveils the extended scattering environment of GX 13+1
Alessandro Di Marco, Fabio La Monaca, Luigi Stella +17
Neutron star low-mass X-ray binaries feature complex accretion geometries, often including an accretion disk corona or disk winds. Here, a study of the highly inclined dipping sour…
Pulse profile modelling of the 2024 outburst of the accreting millisecond pulsar SRGA J144459.2-604207
Bas Dorsman, Tuomo Salmi, Anna L. Watts +14
Pulse profile modelling via relativistic ray-tracing can constrain the system parameters of neutron stars, notably their mass and radius. Among these objects, accreting millisecond…
The First X-Ray Polarimetry of an Eclipsing Low-Mass X-Ray Binary: Serendipitous IXPE Observation of AX J1745.6-2901
Romana Mikušincová, Lorenzo Marra, Hemanth Manikantan +38
We present the first X-ray polarimetric measurement of the neutron star low-mass X-ray binary system AX J1745.6-2901 conducted by the Imaging X-ray Polarimetry Explorer (IXPE) sate…
Super-Eddington Accretion Geometry: a Remarkable Stability of the Hidden Ultraluminous X-Ray Source Cygnus X-3
Romana Mikušincová, Alexandra Veledina, Fabio Muleri +112
We report on the average and orbital phase-resolved polarization of Cyg X-3 in the hard state during the 2023 Imaging X-ray Polarimetry Explorer (IXPE) observational campaign. We f…
Pulse profile modelling of the accretion-powered millisecond pulsar SAX J1808.4-3658 using NICER data from its 2019 and 2022 outbursts
Bas Dorsman, Tuomo Salmi, Anna L. Watts +5
Pulse profile modelling is a relativistic ray-tracing technique that has provided constraints on parameters, with a focus on mass and radius, of five rotation-powered millisecond p…
Probing the polarized emission from the accretion-powered pulsar 4U 1907+09 with IXPE
Menglei Zhou, Lorenzo Ducci, Honghui Liu +12
We present observations of the accretion-powered X-ray pulsar (XRP) 4U 1907+09, conducted with the Imaging X-ray Polarimetry Explorer (IXPE) that delivers the first high-quality po…
IXPE view of the Sco-like source GX 349+2 in the normal branch
Fabio La Monaca, Anna Bobrikova, Juri Poutanen +6
We present a detailed spectropolarimetric study of the Sco-like Z-source GX 349+2, simultaneously observed with the Imaging X-ray Polarimetry Explorer (IXPE) and Nuclear Spectrosco…
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.…
Exploring polarization and geometry in the X-ray pulsar 4U 1538-52
Vladislav Loktev, Sofia V. Forsblom, Sergey S. Tsygankov +12
The Imaging X-ray Polarimetry Explorer (IXPE) observations of accreting X-ray pulsars (XRPs) continue to provide novel insights into the physics and geometry of these sources. We p…
The very high X-ray polarisation of accreting black hole IGRJ17091-3624 in the hard state
Melissa Ewing, Maxime Parra, Guglielmo Mastroserio +26
We report the first detection of the X-ray polarisation of the transient black hole X-ray binary IGRJ17091-3624 taken with the Imaging X-ray polarimetry Explorer (IXPE) in March 20…
X-ray Dips and Polarization Angle Swings in GX 13+1
Alessandro Di Marco, Fabio La Monaca, Anna Bobrikova +8
We present the result from the April 2024 observation of the low-mass X-ray binary GX 13+1 with the Imaging X-ray Polarimetry Explorer (IXPE), together with NICER and Swift-XRT coo…
Modelling polarized X-ray pulses from accreting millisecond pulsars with X-PSI, using different hot spot locations and shapes
Tuomo Salmi, Bas Dorsman, Anna L. Watts +7
We present an analysis of polarized X-ray pulses based on simulated data for accreting millisecond pulsars (AMPs). We used the open-source X-ray Pulse Simulation and Inference code…
Polarized radiation from the spreading layer of the weakly magnetized neutron stars
Anna Bobrikova, Juri Poutanen, Vladislav Loktev
Observations show that the X-ray emission of the accreting weakly magnetized neutron stars is polarized. Here, we develop a theoretical model, where we assume the emission of the a…
Parameter constraints for accreting millisecond pulsars with synthetic NICER data
Bas Dorsman, Tuomo Salmi, Anna L. Watts +10
Pulse profile modelling (PPM) is a technique for inferring mass, radius and hotspot properties of millisecond pulsars. PPM is now regularly used for analysis of rotation-powered mi…
Discovery of Polarized X-Ray Emission from the Accreting Millisecond Pulsar SRGA J144459.2-604207
Alessandro Papitto, Alessandro Di Marco, Juri Poutanen +22
We report on the discovery of polarized X-ray emission from an accreting millisecond pulsar. During a 10-day-long coverage of the February 2024 outburst of SRGA J144459.2-604207, t…
Ultrasoft state of microquasar Cygnus X-3: X-ray polarimetry reveals the geometry of astronomical puzzle
Alexandra Veledina, Juri Poutanen, Anastasiia Bocharova +17
Cygnus X-3 is an enigmatic X-ray binary, that is both an exceptional accreting system and a cornerstone for the population synthesis studies. Prominent X-ray and radio properties f…
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…
Probing the polarized emission from SMC X-1: the brightest X-ray pulsar observed by IXPE
Sofia V. Forsblom, Sergey S. Tsygankov, Juri Poutanen +101
Recent observations of X-ray pulsars (XRPs) performed by the Imaging X-ray Polarimetry Explorer (IXPE) have made it possible to investigate the intricate details of these objects i…
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…
New polarimetric study of the galactic X-ray burster GX 13+1
Anna Bobrikova, Alessandro Di Marco, Fabio La Monaca +3
Weakly magnetized neutron stars (WMNS) are complicated sources with challenging phenomenology. For decades, they have been studied via spectrometry and timing. It has been establis…
Discovery of a strong rotation of the X-ray polarization angle in the galactic burster GX 13+1
Anna Bobrikova, Sofia V. Forsblom, Alessandro Di Marco +106
Weakly magnetized neutron stars in X-ray binaries show complex phenomenology with several spectral components that can be associated with the accretion disk, boundary and/or spread…
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)…
Polarized radiation from an accretion shock in accreting millisecond pulsars using exact Compton scattering formalism
Anna Bobrikova, Vladislav Loktev, Tuomo Salmi +1
Pulse profiles of accreting millisecond pulsars can be used to determine neutron star (NS) parameters, such as their masses and radii, and therefore provide constraints on the equa…