75 citations · 272 across the 21 of their papers we have counts for
25 papers
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…
The 2025 Failed Outburst of IGR J17091-3624: Spectral Evolution and the Role of Ionized Absorbers
Oluwashina K. Adegoke, Javier A. Garcia, Guglielmo Mastroserio +15
IGR J17091-3624 is the only black hole X-ray binary candidate, aside from the well-studied black hole system GRS 1915+105, observed to exhibit a wide range of structured variabilit…
Exploring MAXI J1744-294: IXPE insights into a Newly Discovered X-ray Transient
Lorenzo Marra, Romana Mikušincová, Federico M. Vincentelli +33
We present the first IXPE spectro-polarimetric observation of the black hole candidate MAXI J1744294, a transient X-ray source discovered during a bright 2025 outburst in the Ga…
Reprocessing from highly ionized gas in the soft spectral state of V4641 Sgr with NuSTAR
Riley M. T. Connors, Joey Neilsen, Aarran W. Shaw +6
V4641 Sgr is a low-mass black hole X-ray binary system with somewhat puzzling spectral characteristics during its soft state. Recent high-resolution spectroscopic studies of V4641…
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…
Connecting the X-ray/UV variability of Fairall 9 with NICER: A Possible Warm Corona
Ethan R. Partington, Edward M. Cackett, Rick Edelson +7
The Seyfert 1 AGN Fairall 9 was targeted by NICER, Swift, and ground-based observatories for a 1000-day long reverberation mapping campaign. The following analysis of NICER s…
Characterizing the Broadband Reflection Spectrum of MAXI J1803-298 During its 2021 Outburst with NuSTAR and NICER
Oluwashina Adegoke, Javier Garcia, Riley Connors +12
MAXI J1803-298 is a transient black hole candidate discovered in May of 2021 during an outburst that lasted several months. Multiple X-ray observations reveal recurring "dipping" i…
Self-Consistent Disk-Reflection Analysis of the Black-Hole Candidate X-ray Binary MAXI J1813-095 with NICER, Swift, Chandra, and NuSTAR
Santiago Ubach, James F. Steiner, Jiachen Jiang +5
We present our analysis of MAXI J1813-095 during its hard state ``stalled'' outburst in 2018. This self-consistent analysis has been carried out using \NICER, \Swift, \Chandra, and…
Proof of principle X-ray reflection mass measurement of the black hole in H1743-322
Edward Nathan, Adam Ingram, James F. Steiner +9
The black hole X-ray binary H1743-322 lies in a region of the Galaxy with high extinction, and therefore it has not been possible to make a dynamical mass measurement. In this pape…
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…
Long term variability of Cygnus X-1. VIII. A spectral-timing look at low energies with NICER
Ole König, Guglielmo Mastroserio, Thomas Dauser +19
The Neutron Star Interior Composition Explorer (NICER) monitoring campaign of Cyg X-1 allows us to study its spectral-timing behavior at energies keV across all states. The…
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…
The First High-Contrast Images of Near High-Mass X-Ray Binaries with Keck/NIRC2
M. Prasow-Émond, J. Hlavacek-Larrondo, K. Fogarty +10
Although the study of X-ray binaries has led to major breakthroughs in high-energy astrophysics, their circumbinary environment at scales of 100--10,000 astronomical units ha…
Dramatic Drop in the X-Ray Polarization of Swift J1727.81613 in the Soft Spectral State
Jiří Svoboda, Michal Dovčiak, 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…
Highly-coherent quasi-periodic oscillations in the 'heartbeat' black hole X-ray binary IGR J17091-3624
Jingyi Wang, Erin Kara, Jeroen Homan +13
IGR J17091-3624 is a black hole X-ray binary (BHXB), often referred to as the 'twin' of GRS 1915+105 because it is the only other known BHXB that can show exotic 'heartbeat'-like v…
The 2022 Outburst of IGR J17091-3624: Connecting the exotic GRS 1915+105 to standard black hole X-ray binaries
Jingyi Wang, Erin Kara, Javier A. García +13
While the standard X-ray variability of black hole X-ray binaries (BHXBs) is stochastic and noisy, there are two known BHXBs that exhibit exotic `heartbeat'-like variability in the…
Evidence for a dynamic corona in the short-term time lags of black hole X-ray binary MAXI J1820+070
Niek Bollemeijer, Phil Uttley, Arkadip Basak +19
In X-ray observations of hard state black hole X-ray binaries, rapid variations in accretion disc and coronal power-law emission are correlated and show Fourier-frequency-dependent…
X-ray Polarization of the Eastern Lobe of SS 433
Philip Kaaret, Riccardo Ferrazzoli, Stefano Silvestri +103
How astrophysical systems translate the kinetic energy of bulk motion into the acceleration of particles to very high energies is a pressing question. SS 433 is a microquasar that…
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)…
A Possible Third Body in the X-Ray System GRS 1747-312 and Models with Higher-Order Multiplicity
Caleb Painter, Rosanne Di Stefano, Vinay L. Kashyap +7
GRS 1747-312 is a bright Low-Mass X-ray Binary in the globular cluster Terzan 6, located at a distance of 9.5 kpc from the Earth. It exhibits regular outbursts approximately every…
IXPE observation confirms a high spin in the accreting black hole 4U 1957+115
L. Marra, M. Brigitte, N. Rodriguez Cavero +113
We present the results of the first X-ray polarimetric observation of the low-mass X-ray binary 4U 1957+115, performed with the Imaging X-ray Polarimetry Explorer in May 2023. The…
Discovery of a variable energy-dependent X-ray polarization in the accreting neutron star GX 5-1
Sergio Fabiani, Fiamma Capitanio, Rosario Iaria +116
We report on the coordinated observations of the neutron star low-mass X-ray binary (NS-LMXB) \gx in X-rays (IXPE, NICER, Nustar and INTEGRAL), optical (REM and LCO), near-infrared…
Detection of Reflection Features in the Neutron Star Low-Mass X-ray Binary Serpens X-1 with NICER
R. M. Ludlam, J. M. Miller, Z. Arzoumanian +17
We present Neutron Star Interior Composition Explorer (NICER) observations of the neutron star low-mass X-ray binary Serpens X-1 during the early mission phase in 2017. With the hi…