Related papers: Multiband Echo Tomography of Sco X-1
The Imaging X-ray Polarimetry Explorer (IXPE) measured with high significance the X-ray polarization of the brightest Z-source Scorpius X-1, resulting in the nominal 2-8 keV energy band in a polarization degree of 1.0(0.2)% and a…
We present Rossi X-ray Timing Explorer observations of the X-ray pulsar SMC X-1. The source is highly variable on short time scales (< 1 h), exhibiting apparent X-ray flares occupying a significant fraction (~3 %) of the total observing…
We report here detailed timing and spectral analysis of two Beppo-SAX observations of the binary X-ray pulsar LMC X-4 carried out during the low and high states of its 30.5 days long super-orbital period. Timing analysis clearly shows 13.5…
[abridged] Three years of optical monitoring of the low-mass X-ray binary (LMXB) 4U 1957+11 is presented. The source was observed in V, R and i-bands using the Faulkes Telescopes North and South. The light curve is dominated by long-term…
Sco X-1 is the brightest persistent X-ray in the sky. It is generally believed that Sco X-1 is a low-mass X-ray binary containing a neutron star accreting from a low-mass donor star where mass transfer is driven by the magnetic braking.…
We present an optical and infrared (IR) study of IC 10 X-2, a high-mass X-ray binary in the galaxy IC 10. Previous optical and X-ray studies suggest X-2 is a Supergiant Fast X-ray Transient: a large-amplitude (factor of $\sim$ 100),…
We report on the temporal and spectral characteristics of the early X-ray emission from the Gamma Ray Burst 051117A as observed by Swift. The superb quality of the early X-ray light-curve and spectra of this source, one of the brightest…
Cen X-3 is a compact high mass X-ray binary likely powered by Roche lobe overflow. We present a phase-resolved X-ray spectral and timing analysis of two pointed XMM-Newton observations. The first one took place during a normal state of the…
We present a study of the correlated spectral and timing behavior of the new X-ray transient SAX J1711.6-3808 during its 2001 outburst using data obtained with the RXTE. We also investigate the correlations between those source properties…
We present a comprehensive analysis of the optical and infrared (IR) properties of high-mass X-ray binary (HMXB) IC 10 X-2, classified as a super-giant HMXB and super-fast X-ray transient (SFXT) by previous work. Our analysis of regular…
Earlier work showed that the track in the X-ray hardness-intensity diagram of Cir X-1 corresponds to a Z track in its color-color diagram. In this paper, we study the cross spectrum of Cir X-1 in different regions of the hardness-intensity…
We investigate the cross spectrum of XTE J1701-462 in various types of Neutron Star-Low Mass X-ray Binary subclasses, during its 2006-2007 outburst. We analyze the relation between the time lags and temporal variabilities. We find that the…
There is controversy regarding the nature of the suspected donor star to the microquasar GRS 1915+105, and hence whether GRS 1915+105 is a high mass X-ray binary (HMXB) or a low-mass X-ray binary (LMXB). In order to clarify this issue, we…
Lyman break analogs in the local Universe serve as counterparts to Lyman break galaxies (LBGs) at high redshifts, which are widely regarded as major contributors to cosmic reionization in the early stages of the Universe. We studied…
We present the results of timing and spectral analysis of X-ray high state observations of the high-mass X-ray pulsar SMC X-1 with Chandra, XMM-Newton, and ROSAT, taken between 1991 and 2001. The source has L_X ~ 3-5 x 10^38 ergs/s, and the…
We present the first spectral analysis of Scorpius X-1 (Sco X-1) using intentional stray light (SL) observations taken by NuSTAR. Unlike focused observations that have high telemetry load when observing bright sources, intentional SL…
We study RXTE PCA data for the high mass X-ray binary source SMC X-1 between 2003-10 and 2003-12 when the source was in high states. The source is found to be frequently bursting which can be seen as flares in lightcurves on an average of…
The equation of state for ultra-dense matter can be tested from observations of the ratio of mass to radius of neutron stars. This could be measured precisely from the redshift of a narrow line produced on the surface. X-rays bursts have…
High quality, high resolution X-ray spectra were obtained of Sco X-1 with the Reflection Grating Spectrometer (RGS) on board the XMM-Newton satellite. The spectrum around the Oxygen K-edge is searched for signatures indicative for EXAFS.…
We consider the problem of searching for continuous gravitational wave sources orbiting a companion object. This issue is of particular interest because the LMXB's, and among them Sco X-1, might be marginally detectable with 2 years…