Balman, Şölen
We detect dipping activity/modulations in the light curve of the four low-mass X-ray binaries in the 3-10 keV and 20-40 keV energy ranges. The spectral parameters derived from the fits to the International Gamma-Ray Astrophysics Laboratory data are consistent with hot coronal structures in these systems where we find a range of plasma temperatures 3.0-224.9 keV. The unabsorbed X-ray to soft gamma-ray fluxes between 4 keV and 200 keV are 5.9 x 10(-10) erg s(-1) cm(-2) for XB 1916-053, 3.3 x 10(-10) erg s(-1) cm(-2) for XB 1323-619, 21.6 x 10(-10) erg s(-1) cm(-2) for X 1624-490, and 11.0 x 10(-10) erg s(-1) cm(-2) for 4U 1746-371. The optical depth to Compton scattering, tau, varies in a range 4.4-0.002 consistent with electron densities n(e) < 1.4 x 10(15) cm(-3). In general, we find no significant difference in the dip and non-dip spectra in the ISGRI energy range (above 20 keV) for all the four sources. We only detect absorption differences between dipping and non-dipping intervals for XB 1916-053 and X 1624-490 in the JEM-X energy range. Fits in the 4-200 keV range including an additional photoionized absorber model for the two sources show that XB 1916-053 has the highest ionized absorber among the two.


Variations in the dip properties of the low-mass X-ray binary XB 1254-690 observed with XMM-Newton and INTEGRAL
Trigo, M. Diaz; Parmar, A. N.; Boirin, L.; Motch, C.; Talavera, A.; Balman, Şölen (EDP Sciences, 2009-01-01)
We have analysed data from five XMM-Newton observations of XB 1254-690, one of them simultaneous with INTEGRAL, to investigate the mechanism responsible for the highly variable dip durations and depths seen from this low-mass X-ray binary. Deep dips were present during two observations, shallow dips during one and no dips were detected during the remaining two observations. At high (1-4 s) time resolution "shallow dips" are seen to include a few very rapid, deep dips whilst the "deep" dips consist of many s...
The XMM-Newton detection of extended emission from the nova remnant of T Pyxidis
Balman, Şölen (Oxford University Press (OUP), 2010-05-01)
We report the detection of an extended X-ray nebulosity with an elongation from north-east to south-west in excess of 15 arcsec in a radial profile and imaging of the recurrent nova T Pyx using the archival data obtained with the X-ray Multi-Mirror Mission (XMM-Newton), European Photon Imaging Camera (pn instrument). The signal-to-noise ratio in the extended emission (above the point source and the background) is 5.2 over the 0.3-9.0 keV energy range and 4.9 over the 0.3-1.5 keV energy range. We calculate a...
The X-ray spectral evolution of classical Nova V1974 Cygni 1992: A reanalysis of the ROSAT data
Balman, Şölen; Krautter, J; Ogelman, H (IOP Publishing, 1998-05-20)
We present a spectral analysis of the archival X-ray data of classical Nova V1974 Cygni 1992 (Nova Cygni 1992) obtained by the ROSAT Position Sensitive Proportional Counter (PSPC). The X-ray spectrum is fitted with a two-component model. The first component is a white dwarf atmosphere emission model developed for the remnants of classical novae near the Eddington luminosity. The model is used to fit the soft X-ray data in the similar to 0.1-1.0 keV range, where the bulk of emission is below 0.7 keV. The sec...
A Study on W Ursae Majoris-Type Systems Recognised by the ROTSE-IIId Experiment
Coker, D.; ÖZDEMİR, SACİT; YEŞİLYAPRAK, Cahit; Yerli, Sinan Kaan; AKSAKER, NAZIM; Gucsav, B. B. (Cambridge University Press (CUP), 2013-01-24)
We present a study on characterising the light curves of W UMa-type systems gathered from the archive containing 5 years of data observed with the Robotic Optical Transient Search Experiment Telescope (ROTSE-IIId) located in Turkey. A sample of 45 W UMa-type systems was studied on the basis of Fourier decomposition of light curves and some basic geometrical parameters, namely degree of contact (f), mass ratio (q), and orbital inclination (i), as approximated values for these systems were determined. Moreove...
The first resolved and detected classical nova shell in X-rays: The shell of Nova Persei 1901
Balman, Şölen; Ogelman, HB (IOP Publishing, 1999-06-20)
We present the ROSAT High-Resolution Imager data of the first resolved and detected classical nova shell in the X-ray wavelengths: the shell of Nova Persei 1901. We find that the X-ray nebula is composed of knots/clumps and has an elliptical shape with a total count rate of about 0.01 +/- 0.001 counts s(-1). We estimate that the spectrum is of thermal origin with a luminosity of similar to 8.0 x 10(31) ergs s(-1) and an X-ray temperature of similar to 2.0 x 10(6) K in the 0.1-2.4 keV energy range. The knots...
Citation Formats
Ş. Balman, “A STUDY OF THE LOW-MASS X-RAY BINARY DIP SOURCES XB 1916-053, XB 1323-619, X 1624-490 AND 4U 1746-371 OBSERVED WITH INTEGRAL,” ASTRONOMICAL JOURNAL, pp. 50–62, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57298.