Related papers: Optical Modulation in the X-Ray Binary 4U 1543-624…
Symbiotic X-ray binaries form a subclass of low-mass X-ray binary systems consisting of a neutron star accreting material from a red giant donor star via stellar wind or Roche lobe overflow. Only a few confirmed members are currently known;…
In this paper we present X-Shooter time resolved spectroscopy and RXTE PCA light curves of the ultra-compact X-ray binary candidate 4U 0614+091. The X-Shooter data are compared to the GMOS data analyzed previously by Nelemans et al. (2004).…
Using the Faint Object Spectrograph (FOS) aboard the Hubble Space Telescope, we have obtained the first time-resolved spectra of the King et al. ultraviolet-bright counterpart to the 11-minute binary X-ray source in the core of the globular…
We report the discovery of the likely orbital period of the ultracompact low-mass X-ray binary (LMXB) 2S 0918-549. Using time-resolved optical photometry carried out with the 8-m Gemini South Telescope, we obtained a 2.4-hr long, Sloan r'…
We present timing analysis results for Rossi x-ray Timing Explorer (RXTE) observations of x-ray binary source 4U 1820$-$30 located in the globular cluster NGC 6624. The light curves of observations made between October 1996 and September…
4U 1210-64 is a peculiar X-ray binary that was first discovered in 1978 by the Uhuru satellite. The analysis of the X-ray data revealed a 6.7-day orbital period and an additional long-term modulation that is manifested as low and high flux…
Rossi X-ray Timing Explorer All-Sky Monitor observations of the X-ray source 4U2206+54, previously proposed to be a Be star system, show the X-ray flux to be modulated with a period of approximately 9.6 days. If the modulation is due to…
RX J0806.3+1527 is a candidate double degenerate binary with possibly the shortest known orbital period. The source shows an 100% X-ray intensity modulation at the putative orbital frequency of 3.11 mHz (321.5 s). If the system is a…
4U 1323-619 is a low mass X-ray binary system that shows type I X-ray bursts and dips. The most accurate estimation of the orbital period is 2.941923(36) hrs and a distance from the source that is lower than 11 kpc has been proposed. We aim…
In this work we extend our dynamical study of Ultra Compact X-ray Binaries (UCXB) 4U 1820-30 from Prodan and Murray 2012 to three more UCXBs in globular clusters: 4U 1850-087, 4U 0513-40 and M15 X-2. These three UCXBs have orbital periods <…
We present an analysis of the X-ray variability of three symbiotic X-ray binaries, GX 1+4, 4U 1700+24, and 4U 1954+31, using observations made with the Swift Burst Alert Telescope (BAT) and the Rossi X-ray Timing Explorer (RXTE) All-Sky…
We perform a comprehensive analysis of the superorbital modulation in the ultracompact X-ray source 4U 1820-303, consisting of a white dwarf accreting onto a neutron star. Based on RXTE data, we measure the fractional amplitude of the…
Evidence is emerging that the luminous X-ray sources in the cores of globular clusters may often consist of, or perhaps even as a class be dominated by, ultracompact (P < 1 hr) binary stars. To the two such systems already known, in NGC…
In the absence of detectable pulsations in the eclipsing High Mass X-ray binary 4U 1700-37, the orbital period decay is necessarily determined from the eclipse timing measurements. We have used the earlier reported mid-eclipse time…
We present the results of a study with the Swift Burst Alert Telescope in the 14 - 195 keV range of the long-term variability of 5 low mass X-ray binaries with reported or suspected super-orbital periods -- 4U 1636-536, 4U 1820-303, 4U…
4U 1822-371 is one of the proto-type accretion disk coronal sources with an orbital period of about 5.6 hours. The binary is viewed almost edge-on at a high inclination angle of 83 degrees, which makes it a unique candidate to study binary…
We present results from several years of fast optical photometry of 4U0614+091 (V1055 Orionis), a candidate ultracompact X-ray binary most likely consisting of a neutron star and a degenerate secondary. We find evidence for strong…
We have used the Advanced Camera for Surveys on board the Hubble Space Telescope to image the core of the globular cluster M15 in the far-ultraviolet (FUV) waveband. Based on these observations, we identify the FUV counterpart of the…
We report the discovery using data from the Swift Burst Alert Telescope (BAT) of superorbital modulation in the wind-accretion supergiant high-mass X-ray binaries 4U 1909+07 (= X 1908+075), IGR J16418-4532, and IGR J16479-4514. Together…
The X-ray burster 4U1850-087, located in the Galactic globular cluster NGC6712, is an ultracompact binary (orbital period~21 min),likely harbouring a degenerate companion.The source has been observed at soft gamma-rays several times with…