Spectral measurements of Cyg X-3: A thermal source embedded in hot plasma within a cold shell

摘要: The attempts at unified model fitting to explain the spectral variations in Cyg X-3 suggest equally probable fits with a combination of an absorbed blackbody and separately power law exponential cut-off or composite free-free emission hard X-ray component apart from iron line. These seemingly ordinary but ad hoc mixtures simple mechanisms have profound implication about geometry source. While first set suggests black-hole nature compact object, second is consistent neutron star binary picture. variability energies above 30 keV can provide crucial input for In this paper, we present observations X-3, made our on-going survey galactic extragalactic sources 20–200 energy region, using Large Area Scintillation counter Experiment. data show clear power-law photon spectrum form dN/dE ∼ E−2.8 20 130 range. A comparison earlier that total number photons entire 2–500 band conserved all time given luminosity level irrespective state. We propose behaviour be explained by which thermal source embedded hot plasma formed winds accretion disk within cold shell. high/soft low/hard states are simply manifestation extent surrounding scattering medium seed Comptonized maintained either driven magneto-centrifugal winds.