A view of PKS 2155-304 with XMM-Newton reflection grating spectrometers

We present the high-resolution X-ray spectrum of the BL Lac object PKS 2155-304 taken with the RGS units on board XMM-Newton in 2000 November. We detect an O VII Kalpha resonant absorption line from warm/hot local gas at 21.59 Angstrom (similar to4.5 sigma detection). The line profile is possibly double peaked. We do not confirm the strong 20.02 Angstrom absorption line seen with Chandra and interpreted as z similar to 0.05 O VIII Kalpha. We set a 3 sigma upper limit of 14 mAngstrom on the equivalent width. We also detect the similar to23.5 Angstrom interstellar O I 1s --> 2p line and derive a factor of less than or equal to1.5 subsolar O/H ratio in the interstellar medium along the PKS 2155-304 line of sight.