We present a XMM–Newton observation of Markarian 304 , a Seyfert 1 galaxy at z = 0.066 .
The EPIC data show that MKN 304 is affected by heavy ( N _ { H } \approx 10 ^ { 23 } cm ^ { -2 } ) obscuration due to ionized gas .
A two–phase warm absorber provides an adequate parameterization of this gas .
The ionization parameter of the two components is \xi \approx 6 erg cm ^ { -2 } s ^ { -1 } and \xi \approx 90 erg cm ^ { -2 } s ^ { -1 } , respectively .
The observed continuum photon index ( \Gamma \approx 1.9 ) is typical for Seyfert 1 galaxies .
Two significant emission lines are detected at 0.57 keV and 6.4 keV , respectively .
The former is mostly likely due to He–like oxygen triplet emission arising from an ionized plasma ( maybe the warm absorber itself ) .
The latter is due to fluorescent emission of K–shell iron in a low–ionization state ( FeI–XV ) .
The upper limit for the line width of \sigma _ { K \alpha } < 0.18 keV most likely rules out an origin in the inner parts of the accretion disk .
Interestingly , the strength of such line is consistent with the possibility that the emission is produced in the warm absorber itself .
However , a substantial contribution from the torus is plausible too .
We have also found a weak ( 4 % of the primary continuum ) soft excess emission component .
The presence of this excess could be explained by either emission/scattering from a warm gas or partial covering , or a combination of them .