The 6.7 keV Iron Line Distribution in the Galaxy

We have systematically observed the 6.7 keV iron line emission from the Galactic ridge with the X-ray satellite Ginga. The volume emissivity of the iron line emission from the Galactic ridge is approximated by an exponential disk model plus an arm component of Galactic radius 4 kpc. The scale height of the Galactic ridge emission is determined to be 100 +/- 20 pc. The iron line luminosity from the Galactic ridge is estimated to be (6.5 +/- 1.3) x 10 exp 36 ergs/s, which is about 7 percent of the 2-10 keV band luminosity. We have also discovered another diffuse emission feature near the Galactic bulge with luminosity of about (2.8 +/- 0.8) x 10 exp 36 ergs/s. This emission is found to be extended to a higher Galactic latitude of more than 5 deg.