46 citations · 120 across the 16 of their papers we have counts for
17 papers
Pulse profiles of accreting neutron stars - A review of analysis methods, observations, and theoretical models
Katja Pottschmidt, Peter Kretschmar, Ekaterina Sokolova-Lapa +25
X-ray pulsars are highly magnetized ( G) neutron stars accreting from a donor star. Their characteristic X-ray emission arises from accreted material decelerated fro…
The low luminosity end of Galactic HMXBs with eROSITA: Establishing a luminosity floor for accreting BeXRBs
Aafia Zainab, Philipp Thalhammer, Nico Zalot +18
We present a first look at the Galactic population of heretofore known HMXBs as observed by SRG/eROSITA during its first four surveys. eROSITA's sensitivity of $\sim10^{-13}\,\math…
A simple relation: Neutron star magnetic field strength and spectral shape at low mass accretion rates
Nicolas Zalot, Ekaterina Sokolova-Lapa, Aafia Zainab +8
The X-ray spectra of neutron stars with moderate magnetic fields ( G) in high-mass X-ray binaries (HMXBs) at low X-ray luminosities ( e…
Flux variability of the "10 keV feature" of 4U 0115+63
Katrin Berger, Ekaterina Sokolova-Lapa, Ralf Ballhausen +14
X-ray spectra of accretion-powered X-ray pulsars can often be described using a power-law continuum with a high-energy cutoff, which might be further modified by additional spectra…
Don't torque like that. Measuring compact object magnetic fields with analytic torque models
J. J. R. Stierhof, E. Sokolova-Lapa, K. Berger +10
Context. Changes of the rotational period observed in various magnetized accreting sources are generally attributed to the interaction between the in-falling plasma and the large-s…
Multiwavelength study of 1eRASS J085039.9-421151 with eROSITA NuSTAR and X-shooter
Aafia Zainab, Artur Avakyan, Victor Doroshenko +23
The eROSITA instrument on board Spectrum-Roentgen-Gamma has completed four scans of the X-ray sky, leading to the detection of almost one million X-ray sources in eRASS1 only, incl…
Sharp Periodic Flares and Long-Term Variability in the High-Mass X-ray Binary XTE J1829-098 from RXTE PCA, Swift BAT and MAXI Observations
Robin H. D. Corbet, Ralf Ballhausen, Peter A. Becker +20
XTE J1829-098 is a transient X-ray pulsar with a period of ~7.8 s. It is a candidate Be star system, although the evidence for this is not yet definitive. We investigated the twent…
The giant outburst of EXO 2030+375 II: Broadband spectroscopy and evolution
R. Ballhausen, P. Thalhammer, P. Pradhan +13
In 2021, the high-mass X-ray binary EXO 2030+375 underwent a giant X-ray outburst, the first since 2006, that reached a peak flux of (3-50\,keV). The go…
The giant outburst of EXO 2030+375 I: Spectral and pulse profile evolution
P. Thalhammer, R. Ballhausen, E. Sokolova-Lapa +12
The Be X-ray binary EXO 2030+375 went through its third recorded giant outburst from June 2021 to early 2022. We present the results of both spectral and timing analysis based on N…
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…
An in-depth analysis of the variable cyclotron lines in GX 3012
Nicolas Zalot, Ekaterina Sokolova-Lapa, Jakob Stierhof +13
Context. The High-Mass X-ray Binary (HMXB) system GX 3012 is a persistent source with a well-known variable cyclotron line centered at 35 keV. Recently, a second cyclotron line…
The unaltered pulsar: GRO J1750-27, a super-critical X-ray neutron star that does not blink an eye
C. Malacaria, L. Ducci, M. Falanga +11
When accreting X-ray pulsars (XRPs) undergo bright X-ray outbursts, their luminosity-dependent spectral and timing features can be analysed in detail. The XRP GRO J1750-27 recently…
NuSTAR spectral analysis beyond 79 keV with stray light
G. Mastroserio, B. W. Grefenstette, P. Thalhammer +10
Due to the structure of the NuSTAR telescope, photons at large off-axis (> 1deg) can reach the detectors directly (stray light), without passing through the instrument optics. At t…
Fitting strategies of accretion column models and application to the broadband spectrum of Cen X-3
Philipp Thalhammer, Matthias Bissinger, Ralf Ballhausen +10
Due to the complexity of modeling the radiative transfer inside the accretion columns of neutron star binaries, their X-ray spectra are still commonly described with phenomenologic…
SRG/ART-XC, Swift, NICER and NuSTAR study of different states of the transient X-ray pulsar MAXI J0903-531
Sergey S. Tsygankov, Sergey V. Molkov, Victor Doroshenko +6
The results of the broadband spectral and timing study of the recently discovered transient X-ray pulsar MAXI J0903-531 in a wide range of luminosities differing by a factor of ~30…
Multi-wavelength study of Mrk 421 during a TeV flare
A. Gokus, A. Kreikenbohm, K. Leiter +31
The blazar Mrk 421 shows frequent, short flares in the TeV energy regime. Due to the fast nature of such episodes, we often fail to obtain sufficient simultaneous information about…
X-ray emission from magnetized neutron star atmospheres at low mass accretion rates. I. Phase-averaged spectrum
E. Sokolova-Lapa, M. Gornostaev, J. Wilms +12
Recent observations of X-ray pulsars at low luminosities allow, for the first time, to compare theoretical models for the emission from highly magnetized neutron star atmospheres a…