8 papers
Discovery of Strong Energy-Dependent X-ray Polarization in the Intermediate State of GS 1354-64
Swati Ravi, Lorenzo Marra, James F. Steiner +20
We report the discovery of significant X-ray polarization from the dynamically confirmed black hole X-ray binary (BHXB) GS 1354-64 during its 2025-2026 outburst, obtained with the…
Decoding Cygnus X-2: The Critical Role of Reflection in IXPE Data
Honghui Liu, Jiachen Jiang, Adam Ingram +10
We present a spectro-polarimetric re-analysis of the first IXPE observation of Cygnus X-2 which we determine to be mainly in the normal branch, from quasi-simultaneous observations…
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.…
Cygnus X-3 revealed as a Galactic ultraluminous X-ray source by IXPE
Alexandra Veledina, Fabio Muleri, Juri Poutanen +127
The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds the critical value, known as the Eddington limit. Discovery of ultralumi…
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…
Dramatic Drop in the X-Ray Polarization of Swift J1727.81613 in the Soft Spectral State
JiÅÃ Svoboda, Michal DovÄiak, James F. Steiner +34
Black-hole X-ray binaries exhibit different spectral and timing properties in different accretion states. The X-ray outburst of a recently discovered and extraordinarily bright sou…