Modelling of infrared emission from Cyg X-3 and the UKIRT IRCAM3 point spread function

Abstract Modelling of the point spread function of the UKIRT IRCAM3 array was conducted in order to test for any extended emission around the X-ray binary Cyg X-3. We found that the point spread function cannot be represented by a simple Gaussian, but modelling of the stars required additional functions, namely Lorentzian and exponential components. After modelling for the PSF, we found that Cyg X-3 could be represented by two stellar-type profiles, 0.56″ apart.