371 citations · 692 across the 27 of their papers we have counts for
27 papers
Fingerprints of thermal Comptonization in accreting neutron stars. Plasma-vacuum interplay in cyclotron lines and polarisation
E. Sokolova-Lapa, D. K. Maniadakis, J. J. R. Stierhof +11
X-ray emission from accreting, strongly magnetised neutron stars and its pulse-phase variability probe their magnetic-field geometry, spin orientation, and emission processes. Whet…
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…
Energy-resolved pulse profiles of Vela X-1: cross-calibrating XMM-Newton and NuSTAR to trace spectral features
Dimitrios K. Maniadakis, Antonino D'Aì, Camille M. Diez +12
Pulse profiles probe the emission geometry of accreting X-ray pulsars, but their observed shapes may depend on instrumental response and observational setup. The pulsed fraction sp…
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…
The elusive cyclotron line in 4U 1901+03: hidden, yet present
Elena Ambrosi, Antonino D' Aì, Giancarlo Cusumano +8
Context. Cyclotron resonant scattering features (CRSFs) in accreting X-ray pulsars are often difficult to detect, especially when shallow or variable. Recent studies have shown tha…
How the spin-phase variability of cyclotron lines shapes the pulsed fraction spectra: insights from 4U 1538-52
Dimitrios K. Maniadakis, Ekaterina Sokolova-Lapa, Antonino D'Aì +15
We study the energy-dependent pulse profile of 4U 1538-52 and its phase-dependent spectral variability, with emphasis on the behavior around the cyclotron resonant scattering featu…
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…
Energy-resolved pulse profile changes in V 0332+53: Indications of wings in the cyclotron absorption line profile
Antonino D'Aì, Dimitrios K. Maniadakis, Carlo Ferrigno +15
We aim to investigate the energy-resolved pulse profile changes of the accreting X-ray pulsar V 0332+53, focusing in the cyclotron line energy range, using the full set of availabl…
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…
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…
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 SRG/eROSITA all-sky survey: First X-ray catalogues and data release of the western Galactic hemisphere
A. Merloni, G. Lamer, T. Liu +142
The eROSITA telescope array aboard the Spektrum Roentgen Gamma (SRG) satellite began surveying the sky in December 2019, with the aim of producing all-sky X-ray source lists and sk…
The High Energy X-ray Probe (HEX-P): A New Window into Neutron Star Accretion
R. M. Ludlam, C. Malacaria, E. Sokolova-Lapa +15
Accreting neutron stars (NSs) represent a unique laboratory for probing the physics of accretion in the presence of strong magnetic fields ( G). Additionally, the ma…
Vacuum polarization alters the spectra of accreting X-ray pulsars
E. Sokolova-Lapa, J. Stierhof, T. Dauser +1
It is a common belief that for magnetic fields typical for accreting neutron stars in High-Mass X-ray Binaries vacuum polarization only affects the propagation of polarized emissio…
Accreting on the edge: a luminosity-dependent cyclotron line in the Be/X-ray Binary 2S 1553-542 accompanied by accretion regimes transition
Christian Malacaria, Yash Bhargava, Joel B. Coley +15
Accreting X-ray pulsars (XRPs) undergo luminous X-ray outbursts during which the luminosity-dependent spectral and timing features of the neutron star's emission can be analyzed in…
Continuum, cyclotron line, and absorption variability in the high-mass X-ray binary Vela X-1
C. M. Diez, V. Grinberg, F. Fürst +7
Because of its complex clumpy wind, prominent cyclotron resonant scattering features, intrinsic variability and convenient physical parameters (close distance, high inclination, sm…
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…
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…
NuSTAR observation of GRO J1744-28 at low mass accretion rate
O. König, F. Fürst, P. Kretschmar +8
We present the spectral analysis of the LMXB GRO J1744-28 using 29 ks of NuSTAR data taken in 2017 February at a low luminosity of erg/s (3-50 keV). The c…
Accurate Treatment of Comptonization in X-ray Illuminated Accretion Disks
Javier A. García, Ekaterina Sokolova-Lapa, Thomas Dauser +5
A large fraction of accreting black hole and neutron stars systems present clear evidence of the reprocessing of X-rays in the atmosphere of an optically-thick accretion disk. The…
The giant outburst of 4U 0115+634 in 2011 with Suzaku and RXTE
Matthias Bissinger né Kühnel, Ingo Kreykenbohm, Carlo Ferrigno +19
We present an analysis of X-ray spectra of the high mass X-ray binary 4U 0115+634 as observed with Suzaku and RXTE in 2011 July, during the fading phase of a giant X-ray outburst.…