Near-IR and X-ray Variability of Cyg X-3: Evidence for a Compact IR Source and Complex Wind Structures

Abstract

We study near-infrared (JHK) and X-ray light curves of Cyg X-3 obtained with the 2.5-m telescope of the Caucasian Mountain Observatory of MSU SAI and collected from RXTE ASM and MAXI archives. The light curves in the X-ray and IR domains are strongly affected by irregular variations. However, the mean curves are remarkably stable and qualitatively similar in both domains. This means that the IR flux of the system originates not only from the free-free radiation of the WR wind but also from a compact IR source located near the relativistic companion. The shape of the mean X-ray and IR light curves suggest the existence of two additional structures in the WR wind - a bow shock near the relativistic companion and a so-called "clumpy trail" (Vilhu et al. 2013). Modeling of the mean X-ray and IR light curves allowed us to obtain important system parameters: the orbital phase of the superior conjunction of the relativistic companion ${\varphi }_0=-0.066\pm 0.006$, the orbital inclination angle $i=29.5^{\circ }\pm 1.2^{\circ }$, and the WR mass-loss rate $\dot{M}=(0.96\pm 0.14)\times 10^{-5}{\mathrm{M}}_{\odot }\mathrm{y}{\mathrm{r}}^{-1}$. By using relations between $\dot{M}$ and the rate of the period change and between $\dot{M}$ and the WR mass, we estimated the probable mass of the relativistic companion $M_{\mathrm{C}}\simeq 7.2{\mathrm{M}}_{\odot }$ which points towards the black hole hypothesis. However, this estimate is based on the assumption of a smooth WR wind. Considering the uncertainty associated with clumping, the mass-loss rate can be lower which leaves room for the neutron star hypothesis.

arXiv comment23 pages, 11 figures, accepted by ApJ

References in corpus (24)

• MCMC using Hamiltonian dynamics
• A One-sided, Highly Relativistic Jet from Cygnus X-3
• JHK Observations of Faint Standard Stars in the Mauna Kea Near-Infrared Photometric System
• Cyg X-3: a low-mass black hole or a neutron star
• Superorbital variability of X-ray and radio emission of Cyg X-1 - II. Dependence of the orbital modulation and spectral hardness on the superorbital phase
• Orbital dynamics of Cygnus X-3
• Orbital modulation of X-ray emission lines in Cygnus X-3
• Determining the Distance of Cyg X-3 with its X-ray Dust Scattering Halo
• Effects of the stellar wind on X-ray spectra of Cygnus X-3
• ASTRONIRCAM - infrared camera-spectrograph for Sternberg institute 2.5 METER TELESCOPE
• A comprehensive study of high-energy gamma-ray and radio emission from Cyg X-3
• Gemini/GNIRS infrared spectroscopy of the Wolf-Rayet stellar wind in Cygnus X-3
• Compton scattering as the explanation of the peculiar X-ray properties of Cyg X-3
• Energy-dependent orbital modulation of X-rays and constraints on emission of the jet in Cyg X-3
• First e-VLBI observations of Cygnus X-3
• Photoionization Emission Models for the Cyg X-3 X-ray Spectrum
• CG X-1: an eclipsing Wolf-Rayet ULX in the Circinus galaxy
• A 2.4 - 12 microns spectrophotometric study with ISO of Cygnus X-3 in quiescence
• On the Spin of the Black Hole in IC 10 X-1
• Cygnus X-3 with ISO: investigating the wind
• Jet evolution, flux ratios and light-travel time effects
• The Period Change and Long-Term Variability of Cyg X-3
• Wind suppression by X-rays in Cygnus X-3
• Modeling the X-ray light curves of Cygnus X-3. Possible role of the jet

Cited by in corpus (12)

• A catalogue of high-mass X-ray binaries in the Galaxy: from the INTEGRAL to the Gaia era
• Cygnus X-3 revealed as a Galactic ultraluminous X-ray source by IXPE
• Ultrasoft state of microquasar Cygnus X-3: X-ray polarimetry reveals the geometry of astronomical puzzle
• On the Neutron Star/Black Hole Mass Gap and Black Hole Searches
• Galactic transient sources with the Cherenkov Telescope Array Observatory
• The innermost jet in the hidden ultra-luminous X-ray source Cygnus X-3
• Spectral Analysis of Cyg X-3 using simultaneous AstroSat and Insight-HXMT Observations
• The constraining power of X-ray polarimetry: detailed structure of the intrabinary bow shock in Cygnus X-3
• Empirical correlation between masses of black holes and Wolf-Rayet stars derived from their mass distributions in spectroscopic binaries
• Birthplaces of X-ray emission lines in Cygnus X-3
• Relativistic Scattering in the Funnel of Cygnus X-3
• Diagnosing the Properties and Evolutionary Fates of Black Hole and Wolf-Rayet X-ray Binaries as Potential Gravitational Wave Sources for the LIGO-Virgo-KAGRA Network