Chandra Observation of 3c 212: a New Look at the X-ray and Uv Absorbers

The red quasar 3C212 (z = 1.049) is one of the most distant and most luminous AGN which has shown evidence of an X-ray warm absorber. In order to further investigate this unusual quasar, we used Chandra/ACIS-S to observe 3C212 for 19.5 ksec, resulting in a net detection of ∼ 4000 counts. The Chandra data confirm the presence of an excess absorbing column NH ≈ 4 × 10 21 cm at the quasar redshift, but we find no compelling evidence for a warm absorber. Using both the Chandra and archival ROSAT PSPC data, we obtain very good fits for both a partially covered neutral absorber and a low-ionization (U = 0.03) photo-ionized absorber. In the ultraviolet, 3C212 shows a strong associated Mg ii absorber. Based on a moderate resolution (80 km s) MMT spectrum we show that the absorber is highly saturated and has a covering fraction less than 60%, implying that the absorber is truly intrinsic to the quasar. Photo-ionization modeling of the Mg ii absorber yields a constraint on the ionization parameter of U < 0.03, inconsistent with a warm UV/X-ray absorber. In addition to our spectral analysis, we find evidence in the ACIS image data for weak extended emission surrounding the quasar as well as emission corresponding to the radio lobes at a distance of 5 from 3C212. The statistical significance of these features is low, but we briefly explore the implications if the detections are valid. Subject headings: quasars: absorption lines — quasars:individual (3C212) — ultraviolet: galaxies — X-rays: galaxies