Related papers: A phase-resolved spectroscopic study of the X-ray …
We analyze the X-ray spectra of the atoll 4U~1705-44 when the source undergoes the island-banana state transition. We use the Rossi X-ray Timing Explorer (RXTE) and BeppoSAX observations for this analysis. We demonstrate that the broad-band…
We have performed pulse phase resolved spectroscopy of the Cyclotron Resonance Scattering Features (CRSF) of some bright accretion powered X-ray pulsars like 1A 1118-61, Vela X-1, A0535+26, XTE J1946+274, 4U 1907+09, 4U 1626-67 and GX 301-2…
In this paper, we review the observational properties of two accreting X-ray pulsars, the persistent source 4U1907+09 and the transient V0332+53. Accreting X-ray pulsars are among the brightest sources in the X-ray sky and are frequently…
4U 1700-37 is a wind-fed high-mass X-ray binary hosting a compact object, likely a neutron star, accreting from O6.5 Iaf+ supergiant HD 153919. Coherent pulsations not firmly detected; magnetic field strength remains uncertain. We analyze…
We present a spectral and timing study of the High Mass X-ray Binary transient source 4U 1700-37 using NuSTAR and ASTROSAT/LAXPC. The source is observed in two different flux states. A combined spectral analysis of NuSTAR's FPMA and FPMB…
In this paper we present a spectroscopic study of six double-lined binaries, five of which were recently discovered in a high-resolution spectroscopic survey of optical counterparts of stellar X-ray sources. Thanks to high-resolution…
Our work focuses on a comprehensive orbital phase dependent spectroscopy of the four High Mass X-ray Binary Pulsars (HMXBPs) 4U 1538-52, GX 301-2, OAO 1657-415 & Vela X-1. We hereby report the measurements of the variation of the absorption…
We present preliminary results on our campaign of observations of the X-ray binary pulsar GX301-2. BeppoSAX observed this source six times in January/February 1998: at the periastron and apoastron, and at other four, intermediate, orbital…
We present new results of uniform spectral analysis of Swift/XRT observations of the X-ray binary system 4U 1957+11. This includes 26 observations of the source made between MJD 54282$-$55890 (2007 July 01 $-$ 2011 November 25). All 26…
Centaurus X-3 is a persistent high-mass X-ray binary with the long-term light curve from the source exhibiting orbit-to-orbit intensity variations with no apparent superorbital periodicity. We used $\sim$13.5 years of MAXI/GSC data to study…
(Abridged) We report on ASCA and BeppoSAX observations of the X-ray source 4U 1700+24 and on (quasi-)simultaneous spectroscopy of its optical counterpart, V934 Her, from the Loiano 1.5-meter telescope. Archival ROSAT and RXTE data as well…
We present spectroscopic X-ray data of two candidate ultra-compact X-ray binaries: 4U~0614+091 and 4U~1543$-$624. We confirm the presence of a broad O VIII Ly$\alpha$ reflection line (at $\approx18\ \AA$) using {\it XMM-Newton} and {\it…
We present a spectral and timing analysis of INTEGRAL observations of two high mass X-ray binaries, 4U 1538-522 and 4U 1907+09. Our timing measurements for 4U 1538-522 find the pulse period to have exhibited a spin-up trend until…
We present the results obtained from broadband spectroscopy of the high mass X-ray binary 4U 1700-37 using data from a Suzaku observation in 2006 September 13-14 covering 0.29-0.72 orbital phase range. The light curves showed significant…
We present results of observations of the transient X-ray pulsar V0332+53 performed during a very powerful outburst in Dec, 2004 -- Feb, 2005 with the INTEGRAL and RXTE observatories in a wide (3-100 keV) energy band. A cyclotron resonance…
Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disk. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in…
The persistent Be/X-ray binary RX J0440.9+4431 flared in 2010 and 2011 and has been followed by various X-ray facilities Swift, RXTE, XMM-Newton, and INTEGRAL. We studied the source timing and spectral properties as a function of its X-ray…
We report on two new XMM-Newton observations of the Anomalous X-ray Pulsar (AXP) 4U 0142+614 performed in March and July 2004, collecting the most accurate spectrum for this source to date. Furthermore, we analyse two short archival…
In June-September 2006 the Be/X-ray binary EXO 2030+375 experienced the second giant outburst since its discovery. The source was shown to have a complicated pulse-averaged X-ray spectral continuum with possible evidence of cyclotron…
We have performed a detailed study of the broadband spectra of the luminous globular cluster X-ray sources using BeppoSAX. With the exception of X2127+119, located in NGC7078, all the other spectra are well represented by a two component…