Modeling the X-ray light curves of Cygnus X-3. Possible role of the jet

Abstract

Context: Physics behind the soft X-ray light curve asymmetries in Cygnus X-3, a well-known microquasar, was studied. AIMS: Observable effects of the jet close to the line-of-sight were investigated and interpreted within the frame of light curve physics. METHODS: The path of a hypothetical imprint of the jet, advected by the WR-wind, was computed and its crossing with the line-of-sight during the binary orbit determined. We explore the possibility that physically this 'imprint' is a formation of dense clumps triggered by jet bow shocks in the wind ("clumpy trail"). Models for X-ray continuum and emission line light curves were constructed using two absorbers: mass columns along the line-of-sight of i) the WR wind and ii) the clumpy trail, as seen from the compact star. These model light curves were compared with the observed ones from the RXTE/ASM (continuum) and Chandra/HETG (emission lines). Results: We show that the shapes of the Cygnus X-3 light curves can be explained by the two absorbers using the inclination and true anomaly angles of the jet as derived in Dubus et al. (2010) from gamma-ray Fermi/LAT observations. The clumpy trail absorber is much larger for the lines than for the continuum. We suggest that the clumpy trail is a mixture of equilibrium and hot (shock heated) clumps. Conclusions: A possible way for studying jets in binary stars when the jet axis and the line-of-sight are close to each other is demonstrated. The X-ray continuum and emission line light curves of Cygnus X-3 can be explained by two absorbers: the WR companion wind plus an absorber lying in the jet path (clumpy trail). We propose that the clumpy trail absorber is due to dense clumps triggered by jet bow shocks.

7 pages, 8 figures, Accepted for publication in Astronomy and Astrophysics 16.12.2012

References in corpus (6)

• Physical Properties of Wolf-Rayet Stars
• A catalogue of low-mass X-ray binaries in the Galaxy, LMC, and SMC (Fourth edition)
• Effects of the stellar wind on X-ray spectra of Cygnus X-3
• Spectral variability in Cygnus X-3
• On the interaction of microquasar jets with stellar winds
• First e-VLBI observations of Cygnus X-3

Cited by in corpus (10)

• Periodic signals from the Circinus region: two new cataclysmic variables and the ultraluminous X-ray source candidate GC X-1
• Near-IR and X-ray Variability of Cyg X-3: Evidence for a Compact IR Source and Complex Wind Structures
• The effects of the stellar wind and orbital motion on the jets of high-mass microquasars
• Scale invariant jets: from blazars to microquasars
• Phase-resolved spectral analysis of the 11 millihertz quasi-periodic oscillation in the black-hole candidate H1743-322
• Relativistic stellar jets: dynamics and non-thermal radiation
• Extending the "Energetic Scaling of Relativistic Jets From Black Hole Systems" to Include $\gamma$-ray-loud X-ray Binaries
• Smearing of mass accretion rate variation by viscous processes in accretion disks in compact binary systems
• Birthplaces of X-ray emission lines in Cygnus X-3
• The constraining power of X-ray polarimetry: detailed structure of the intrabinary bow shock in Cygnus X-3