  We present the Chandra-LETGS analysis of Mrk 279, a bright Seyfert 1 galaxy.
The spectrum shows a variety of features arising from different physical
environments in the vicinity of the black hole. We detect three absorption
components, located at the redshift of the source. One of them is likely to
arise from the host galaxy. An additional component due to absorption by a
collisionally ionized gas at z=0 is also observed. Such an absorption can be
produced in the outskirts of our Galaxy or in the local group. The emission
spectrum is rich in narrow and broad emission features. We tested the
hypothesis that the broad emission lines originate in the Broad Line Region
(BLR), as studied in the UV band. We find that at least 2 components with
different ionization parameters are necessary to simultaneously interpret the
broad emission line measured in the UV (by HST-STIS and FUSE) and in the
X-rays.
