Related papers: Cyclotron Line Variability
Cyclotron resonance scattering features observed in the spectra of some X-ray pulsars show significant changes of the line centroid energy with the pulsar luminosity. Whereas for bright sources above the so called critical luminosity these…
OAO 1657-415 is an accreting X-ray pulsar with a high mass companion that has been observed by several telescopes over the years, in different orbital phases. Back in 1999, observations performed with Beppo-SAX lead to the detection of a…
We report the timing and spectral properties of Be/X-ray binary pulsar GX 304-1 by using two Suzaku observations during its 2010 August and 2012 January X-ray outbursts. Pulsations at ~275 s were clearly detected in the light curves from…
The results of the broadband spectral and timing study of the transient X-ray pulsar GRO J2058+42 in a wide energy range at a low luminosity $L_{x} \simeq 2.5\times 10^{36}$ erg s$^{-1}$ are reported. The data revealed that the pulse…
Context: Be/X-ray binaries show outbursts with peak luminosities up to a few times $10^{37}\,$erg/s, during which they can be observed and studied in detail. Most (if not all) Be/X-ray binaries harbour accreting pulsars, whose X-ray spectra…
We report on the results of the longest uninterrupted observation of the Anomalous X-ray Pulsar 1RXS J1708-4009 obtained with the BeppoSAX satellite in August 2001. In the phase-resolved spectrum, corresponding to the rising part of the…
We present timing and broad-band spectral studies of the high mass X-ray binary pulsar 4U 1909+07 using data from Suzaku observation during 2010 November 2-3. The pulse period of the pulsar is estimated to be 604.11+/-0.14 s. Pulsations are…
We report the results of a long observation of the anomalous X-ray pulsar 1RXS J170849-400910 obtained with the BeppoSAX satellite in August 2001. The best-fit phase-averaged spectrum was an absorbed power law plus blackbody model, with…
We studied spectra for 34 accretion-powered X-ray and one millisecond pulsars that were within the field of view of the INTEGRAL observatory over two years (December 2002 - January 2005) of its in-orbit operation and that were detected by…
We report the first report on cyclotron line studies with the LAXPC instrument onboard AstroSat of the High mass X-ray Binary pulsar 4U 1538-52. During the observation of source which spanned about one day with a net exposure of 50 ks,the…
We present a detailed study of the high mass X-ray binary Vela X-1, using observations performed by Insight-HXMT in 2019 and 2020, concentrating on timing analysis and spectral studies including pulse phase-resolved spectroscopy. The…
In 2015 October, the Be/X-ray binary 4U 0115+63 underwent a type II outburst, reaching an X-ray luminosity of $\sim$ {\DP{38}\es}. During the outburst, Nuclear Spectroscopic Telescope Array ({\it NuSTAR}) performed two Target of Opportunity…
We present a detailed analysis of observations of the high mass X-ray binary Cen X-3 spanning two consecutive binary orbits performed with the RXTE satellite in early March 1997. The PCA and HEXTE light curves both show a clear reduction in…
We report on the spectral analysis of the X-ray pulsar LMC X-4 in its high state out of eclipse observed by BeppoSAX. During this observation no coherent pulsations are detected. The primary continuum is well described by a power law with a…
The systematic search for the presence of cyclotron lines in the spectra of accreting X-ray pulsars is being carried on with the BeppoSAX satellite since the beginning of the mission. These highly successful observations allowed the…
We present both timing and spectral analysis of the outburst of 4U 0115+63 in April -- May 2008 with INTEGRAL and RXTE observations. We have determined the spin period of the neutron star at $\sim 3.61430 \pm 0.00003$ s, and a spin up rate…
We report on the 20 ksec observation of Vela X-1 performed by BeppoSAX on 1996 July 14 during its Science Verification Phase. We observed the source in two intensity states, characterized by a change in luminosity of a factor ~ 2, and a…
The X-ray energy spectra and Normalized Power Spectral Densities (NPSDs) of an X-ray nova, GS 2000+25, were investigated. The X-ray energy spectra of the source consist of two components: a hard component, which can be represented by a…
We present results from the first Suzaku observation of the high-mass X-ray binary 4U 1538-522. The broad-band spectral coverage of Suzaku allows for a detailed spectral analysis, characterizing the cyclotron resonance scattering feature at…
Using recent compilations of detailed X-ray observations and spectral models of exceptional quality, we record the electron cyclotron resonance absorption (ECRA) features that have been detected in 45 pulsating high-mass X-ray binaries…