Orbital Phase Resolved Spectroscopy of EX Hya Using XMM-NEWTON

Abstract

We present for the first orbital phase resolved spectra of intermediate polar (IP), EX Hya, during two different states with a factor of 3 difference between the X-ray count rates. We find definite spectral variations between different states of the source. The adopted model is composed of two MEKAL plus a VMCFLOW components to account for the continuum which is partially absorbed. Additional Gaussian lines at energies similar to 6,4, 6.7 and 6.9 keV were also included to fit the residuals. The soft component of the spectrum is found to be harder during orbital minimum, suggesting the presence of extra ionized absorbing column. Moreover, the presence of cold emission Fek alpha line points toward the presence of a reflection component probably due to an accretion disk and/or a bulge at the impact zone.