The Kinematics and Physical Conditions of the Ionized Gas in Markarian 509. I.ChandraHigh Energy Grating Spectroscopy

We observed the Seyfert 1 galaxy Mrk 509 simultaneously with Chandra/HETG,HST/STIS and RXTE. We measure strong absorption lines from He-like Ne and Mg,and from H-like N, O, and Ne. The lines are unresolved except for Ne Lya and NeIX(r). The absorption-line profiles are blueshifted by ~200 km/s with respectto the systemic velocity of Mrk 509, and there is a hint of another componentnear systemic. The soft X-ray spectrum can be described in remarkable detailwith a simple, single-zone photoionized absorber with a column density of 2.06(+0.39,-0.45) x 10^21 cm^-2 and an ionization parameter of log{xi} = 1.76(+0.13,-0.14) (or log{U}=0.27). The UV data, on the other hand, can easilydetect eight kinematic components, covering roughly the same velocities as theX-ray absorption profiles. Even though the X-ray and UV absorbers share thesame velocity space, the UV absorbers have a much smaller column density andionization state. We show that models of the X-ray data do not predictsignificant UV absorption and are therefore consistent with the UV data. The UVabsorbers could be embedded in the X-ray absorber, as a multiphase medium.Finally, we do not detect any soft X-ray emission lines.Comment: Accepted for publication in the Astrophysical Journal. 66 pages, 14 figures, six of them color. Abstract is abridge