  We analyse WMAP 7-year temperature data, jointly modeling the cosmic
microwave background (CMB) and Galactic foreground emission. We use the
Commander code based on Gibbs sampling. Thus, from the WMAP7 data, we derive
simultaneously the CMB and Galactic components on scales larger than 1deg with
sensitivity improved relative to previous work. We conduct a detailed study of
the low-frequency foreground with particular focus on the "microwave haze"
emission around the Galactic center. We demonstrate improved performance in
quantifying the diffuse galactic emission when Haslam 408MHz data are included
together with WMAP7, and the spinning and thermal dust emission is modeled
jointly. We also address the question of whether the hypothetical galactic haze
can be explained by a spatial variation of the synchrotron spectral index. The
excess of emission around the Galactic center appears stable with respect to
variations of the foreground model that we study. Our results demonstrate that
the new galactic foreground component - the microwave haze - is indeed present.
