Related papers: Phase dependent evolution within large luminosity …
The Be/X-ray binary 1A 0535+262 underwent a giant X-ray outburst in November 2020, peaking at $\sim1\times 10^{38}$ erg s$^{-1}$ (1--100 keV, 1.8 kpc), the brightest outburst recorded for this source so far. Our goal is to search for…
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 investigate the cyclotron resonant scattering features (CRSFs) of the accreting X-ray pulsar Cen X-3 and significantly detect the 29 keV cyclotron line features in the hard X-ray averaged spectroscopy studies based on the recent…
We present two observations of the high-mass X-ray binary GX 301-2 with NuSTAR, taken at different orbital phases and different luminosities. We find that the continuum is well described by typical phenomenological models, like a very…
We present pulse phase resolved spectra of the hypergiant high mass X-ray binary GX 301-2. We observed the source in 2001 October with RXTE continuously for a total on-source time of almost 200ksec. We model the continuum with both, a…
We report a detailed timing and spectral analysis of the X-ray pulsar 2S~1417-624 using the data from Insight-HXMT during the 2018 outburst. The pulse profiles are highly variable with respect to both unabsorbed flux and energy. A…
We report on the BeppoSAX monitoring of a giant outburst of the transient X-ray pulsar XTE J1946+274 in 1998. The source was detected with a flux of ~ 4 x 10^(-9) erg cm^(-2) s^(-1) (in 0.1 - 120 keV range). The broadband spectrum, typical…
Using a consistent set of models, we parameterized the X-ray spectra of all accreting pulsars in the Rossi X-ray Timing Explorer database which exhibit Cyclotron Resonance Scattering Features (CRSFs, or cyclotron lines). These sources in…
We present an extended study of the Be/X-ray pulsar 2S 1553-542 during its Type II outbursts. We have incorporated \emph{NICER, Swift-XRT, RXTE-PCA, \emph{NuSTAR} and FERMI} observations to carry out the detailed phase and time resolved…
We study the spectral and temporal behavior of the High Mass X-ray Binary A 0535+26 during a `pre-outburst flare' which took place ~5 d before the peak of a normal (type I) outburst in August/September 2005. We compare the studied behavior…
Accretion onto magnetic neutron stars results in X-ray spectra that often exhibit a cyclotron resonance scattering feature (CRSF) and, sometimes, higher harmonics of it. Two places are suspect for the formation of a CRSF: the surface of the…
We study the variations in the Cyclotron Resonant Scattering Feature (CRSF) during 2011 outburst of the high mass X-ray binary 4U 0115+63 using observations performed with Suzaku, RXTE, Swift and INTEGRAL satellites. The wide-band spectral…
We report comprehensive spectral and temporal properties of the Be/X-ray binary pulsar SMC X-2 using X-ray observations during the 2015 and 2022 outbursts. The pulse profile of the pulsar is unique and strongly luminosity dependent. It…
We present NICER observations of accreting X-ray pulsar 1A 0535+262 during its faint state ($\lesssim 6\times10^{36}$ erg/s) observed in several type I and II outbursts. We discovered a transition of temporal and spectral properties around…
Her X-1 is one of the the most intensively studied Accreting X-ray Binary Pulsars (AXBPs). This is largely because it is a bright and persistent X-ray pulsar, showing the largest variety of observable phenomena, partly due to the favorable…
A number of accreting X-ray pulsars experience spectral changes, both on the long time scales and on the time scales of the neutron star spin period. The sources seem to form two distinct groups which differ by the type of the spectral…
We present the results of the neutron star X-ray binary system Cen X-3 performed by $Insight$-HXMT with two observations during 2017 and 2018. During these two observations, the source reached a X-ray luminosity of $\sim 10^{38}$ erg…
We present a comprehensive analysis of Vela X-1 using two new NuSTAR observations, placed in the context of four earlier datasets obtained between 2012 and 2020. The energy-resolved pulse profiles demonstrate a significant transformation…
Based on HXMT observations of EXO 2030+375 during its 2021 giant outburst, we report the analysis of pulse variations and the broadband X-ray spectrum, and find the presence of a potential cyclotron resonant scattering feature with the…
Magnetic neutron stars (NSs) often exhibit a cyclotron resonant scattering feature (CRSF) in their X-ray spectra, but the site of the CRSF formation is still an open puzzle. A promising candidate for high-luminosity sources has always been…