2009/04/22 by Ş. Balman, Solen Balman
Earth and Planetary Sciences · Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #High-pressure geophysics and materials #Materials science #Optics #Physics #Pulsars and Gravitational Waves Research #Range (aeronautics) #Spectral line #X-ray #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.1088/0004-6256/138/1/50
27 pages, 7 figures, 4 tables, accepted as it stands in the Astronomical Journal
arxiv created 2009/04/22 · openalex publication_date 2009/05/21 · arxiv updated 2015/05/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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 × 10 −10 erg s −1 cm −2 for XB 1916 − 053, 3.3 × 10 −10 erg s −1 cm −2 for XB 1323 − 619, 21.6 × 10 −10 erg s −1 cm −2 for X 1624 − 490, and 11.0 × 10 −10 erg s −1 cm −2 for 4U 1746 − 371. The optical depth to Compton scattering, τ, varies in a range 4.4–0.002 consistent with electron densities n e < 1.4 × 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.