329 citations · 900 across the 19 of their papers we have counts for
20 papers
An apparent positive relation between spin and orbital angular momentum in X-ray binaries
Zhen Yan, Wenda Zhang, Wenfei Yu
The origin of current angular momentum (AM) of the black hole (BH) in X-ray binary (XRB) is still unclear, which is related with the birth and/or the growth of the BH. Here we coll…
X-ray Polarimetry as a Tool to Measure the Black Hole Spin in Microquasars: Simulations of IXPE Capabilities
Romana Mikusincova, Michal Dovciak, Michal Bursa +5
Measurements of the angular momentum (spin) of astrophysical black holes are extremely important, as they provide information on the black hole formation and evolution. We present…
Investigating the X-ray polarization of lamp-post coronae in BHXRB
Wenda Zhang, Michal Dovčiak, Michal Bursa +3
High-sensitivity X-ray polarimetric observations of black hole X-ray binaries, which will soon become available with the launches of space-borne X-ray observatories with sensitive…
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…
XMM-Newton detection of soft time lags in the TDE candidate AT 2018fyk
Wenda Zhang
In this letter we report a tentative detection of soft time lags (i.e. variability of softer photons lags behind the variability of harder photons) in one observation…
Coronal properties of black hole X-ray binaries in the hard state as seen by NuSTAR and Swift
Zhen Yan, Fu-guo Xie, Wenda Zhang
In this work, we measure two important phenomenological parameters of corona (and hot accretion flow) in black hole X-ray binaries: the photon index and the electron temperatur…
Role of Coherent Eddies in Potential Vorticity Transport in Two-layer Quasigeostrophic Turbulence
Wenda Zhang, Christopher L. P. Wolfe, Ryan Abernathey
The transport by materially coherent eddies is studied in a two-layer quasigeostrophic model of geophysical turbulence. The coherent eddies are identified by closed contours of the…
Probing the Bardeen-Petterson effect in tidal disruption events with spectral line reverberation mapping
Wenda Zhang, Wenfei Yu, Vladimír Karas +1
For an inclined accretion flow around a rotating black hole, the combined effect of the Lense-Thirring precession and viscous torque tends to align the inner part of the flow with…
The X-ray Polarization Probe mission concept
Keith Jahoda, Henric Krawczynski, Fabian Kislat +100
The X-ray Polarization Probe (XPP) is a second generation X-ray polarimeter following up on the Imaging X-ray Polarimetry Explorer (IXPE). The XPP will offer true broadband polarim…
Constraining the size of the corona with fully relativistic calculations of spectra of extended corona. I - the Monte Carlo radiative transfer code
Wenda Zhang, Michal Dovčiak, Michal Bursa
The size and geometry of the X-ray emitting corona in AGNs are still not well constrained. Dovčiak & Done (2016) proposed a method based on calculations assuming a point-like lamp-…
Polarimetry and strong gravity effects from spots orbiting near a black hole
Vladimir Karas, Michal Dovciak, Jiri Svoboda +4
We study the modulation of the observed radiation flux and the associated changes in the polarization degree and angle that are predicted by the orbiting spot model for flares from…
The enhanced X-ray Timing and Polarimetry mission - eXTP
ShuangNan Zhang, Andrea Santangelo, Marco Feroci +146
In this paper we present the enhanced X-ray Timing and Polarimetry mission - eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of…
The Large Area Detector onboard the eXTP mission
Marco Feroci, Mahdi Ahangarianabhari, Giovanni Ambrosi +68
The eXTP (enhanced X-ray Timing and Polarimetry) mission is a major project of the Chinese Academy of Sciences (CAS) and China National Space Administration (CNSA) currently perfor…
eXTP -- enhanced X-ray Timing and Polarimetry Mission
S. N. Zhang, M. Feroci, A. Santangelo +181
eXTP is a science mission designed to study the state of matter under extreme conditions of density, gravity and magnetism. Primary targets include isolated and binary neutron star…
X-ray outbursts of ESO 243-49 HLX-1: comparison with Galactic low-mass X-ray binary transients
Zhen Yan, Wenda Zhang, Roberto Soria +2
We studied the outburst properties of the hyper-luminous X-ray source ESO 243-49 HLX-1, using the full set of Swift monitoring observations. We quantified the increase in the waiti…
Predictions for reverberating spectral line from a newly formed black hole accretion disk: case of tidal disruption flares
Wenda Zhang, Wenfei Yu, Vladimir Karas +1
Tidal Disruption Events (TDEs) can be perfect probes of dormant SMBHs in normal galaxies. During the rising phase, the accretion luminosity can increase by orders of magnitude in s…
Early Phase Detection and Coverage of Extragalactic and Galactic Black Hole X-ray Transients with the SKA
Wenfei Yu, Hui Zhang, Zhen Yan +1
SKA's large field of view and high sensitivity at low frequencies will provide almost a complete coverage of the very early rising phase of extragalactic and Galactic transients wh…
Low frequency QPOs and possible change in the accretion geometry during the outbursts of Aquila X1
Wenda Zhang, Wenfei Yu
We have studied the evolution of the Low Frequency Quasi-Periodic Oscillations (LFQPOs) during the rising phase of seven outbursts of the neutron star Soft X-ray Transient (SXT) Aq…
Tidal disruption events from a nuclear star cluster as possible origin of transient relativistic spectral lines near SMBH
V. Karas, M. Dovciak, D. Kunneriath +2
We discuss a possibility that a tidal disruption event near a dormant supermassive black hole (SMBH) can give rise to spectral features of iron in 6-7 keV X-ray signal: a relativis…
Energy dependent power spectral states and origin of aperiodic variability in black hole binaries
Wenfei Yu, Wenda Zhang
We found the black hole candidate MAXI J1659-152 showed distinct power spectra, i.e., a power-law noise (PLN) vs. band-limited noise (BLN) plus quasi-periodic oscillations (QPOs),…