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Session 11 - QSOs and Radio Galaxies.
Display session, Monday, June 08
We present the HST FOS observations of the radio-quiet, z_em \simeq 1.202 QSO 0122+0338 in the spectral range (2222-3277 ÅWe report the detection of prominent groups of intervening absorption lines including three highly ionized absorption systems with z_a \simeq 1.166, 1.199, and 1.207. The absorption systems z_a \simeq 1.166 and 1.207 include strong \ionO6 \lambda\lambda 1032, 1038 absorption with \log N(\ionO6)\gtrsim 14.8 cm^-2. The z_a \simeq 1.199 system contains both Ly\alpha and Ly\beta with a relative velocity of \Delta v \sim +400 km s^-1 to the emission redshift. We believe these systems are contained within the environment of the QSO.
The z_a \simeq 1.166 system is very highly ionized given the presence of strong \ionO6 and Ly\alpha lines and the lack of \ionN5 absorption. The relative velocity of \Delta v \sim +4000 km s^-1 places the absorber in the region of the QSO. We believe the source of this absorption system is either collisionally ionized, hot gas in a high density cloud, or non-equilibrium cooling of hot gas (e.g. in the associated galactic halo or the intracluster medium).
The prominent absorption system z_a \simeq 1.207 is discerned by the set of highly ionized lines, including: Ly\alpha \lambda 1216, Ly\beta \lambda 1026, \ionO6 \lambda\lambda 1032, 1038, \ionSi3 \lambda 1207, \ionSi4 \lambda\lambda 1394, 1403 and \ionN5 \lambda\lambda 1239, 1243. All the absorption lines possess a relative velocity of \Delta v \sim -600 km s^-1 indicating inflow relative to the emission redshift. This may be accounted due to gas cloud velocity dispersions within an associated cluster. Nonetheless, it is probable the absorption system is in the proximity of the QSO. Strong \ionN5 absorption (\log N(\ionN5) \gtrsim 14.6 cm^-2) can be interpreted by a nitrogen rich gas expected to be associated with some QSO models. Since the gas may have high metallicity, the high ionization state of the gas is evidence it is physically associated with the QSO itself.
The spectrum also contains galactic absorption lines of low ionization. We measure the rest equivalent widths of these lines to be on the order of several angstroms in agreement with previous interstellar absorption line obsevations.
Program listing for Monday