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Q 1206+459
V = 16.1; z = 1.155; exp = 3600 s; coverage = 3810.5-6304.9 A
The spectrum of QSO has been studied by SS92 and by Burles & Tytler (1996). SS92 reported a Mg II system at z = 0.9729. In a search for O VI absorption, Burles & Tytler reported three redshifts, z = 0.7339, 0.9270, and 1.0827. In the HIRES spectrum, the Mg II doublet was not detected in the z = 0.7339 nor the 1.0827 system. The 5-sigma equivalent width upper limits for Mg II are EW(rest) < 0.015 A. These are clearly highly ionized systems. A weak system at z = 0.9343 was discovered in the HIRES data. Examination of the broad C IV profile in the Key Project FOS spectrum, redward of the very strong C IV absorption, revealed a weak C IV absorber associated with the discovered weak system. Two systems were included in this study.
z=0.927602 A |DATA & VOIGT PROFILES| |EWs & AOD COLUMNS| |VP PARAMETERS|
z=0.927602 B |DATA & VOIGT PROFILES| |EWs & AOD COLUMNS| |VP PARAMETERS|This system is revealed to be a very complex and kinematically spread out system, with a maximum Mg II cloud separation of 500 km/s (greater than the escape velocity of typical L* galaxies). It is possible that this is a "double system", one for which a rich complement of low and high ionization species are seen in absorption. If so, the weak system (call it "A", as presented in Table 3.27) would have a measured redshift of z = 0.9266. It is likely that the bulk of the C IV absorption arises in association with subsystem A, given the lower Mg II absorption strengths that would occur in high ionization gas. Because the FOS data have a resolution of 250 km/s, it is not possible to precisely discern if the strong high ionization conditions are associated with system A, system B, or both. The average redshift of the high ionization "system" is consistent with being centered on subsystem A within the 1-sigma (125 km/s) uncertainty of the measured redshift. However, this is uncertain since the velocity zero point of the FOS data was not addressed by Burles & Tytler. The Mg II profile of system A exhibits the symmetric velocity splittings that are suggestive of shell expansion or radial infall. It is possible that this subset of the profiles could be part of a collisional wind that is also responsible for the O VI, N V, C IV, Si IV, N III, C III, C II, Si II, Ly-alpha, Ly-beta, and Ly-gamma transitions reported by Burles & Tytler. Such a wind could arise from supernovae explosions (Bregman 1980; MacLow & McCray 1988), especially in the low mass potentials of dwarf satellite galaxies (Wang 1993, 1995). Interestingly, there is no Fe II detected to a 5-sigma EW(rest) limit of 0.008 AA over this velocity interval. The bulk of the Mg II absorption arises in system B, presented in Table 3.28. It is likely that the ionization conditions are lower than in system A. Also detected is the Mg I transition and several Fe II transitions. The overall system (A+B) was fit with 12 VP components (six each) over a total of five subfeatures. The Ca II 3934, 3969 doublet was not covered by the HIRES format. The Mn II triplet showed no absorption to the EW(rest) limits given in Table 3.27 and Table 3.28.
z=0.934283 |DATA & VOIGT PROFILES| |EWs & AOD COLUMNS| |VP PARAMETERS|This "weak" Mg II system was discovered in the HIRES spectrum. Only the Mg II doublet was detected to the EW(rest) limits quoted in Table 3.29. The Ca II 3934, 3969 doublet was not covered by the HIRES format. It is unlikely that this system is associated with the z = 0.9276 system(s), given that the velocity separation is 1300 km/s.
Speculations on the "Double System" (circa 1997)For the "double system", the low ionization gas kinematics and the large absorption strengths of the higher ions are suggestive of an active system, or multiple systems with different gaseous phases. A great deal can be learned by comparing the relative line of sight kinematics, spatial separations, individual morphologies, and stellar content of the matter traced by stars, i.e. galaxies. Such detail requires the high spatial resolution imaging provided by WFPC2/HST, both for obtaining morphologies of galaxies and for identifying faint dwarf galaxies in the environment. Three galaxies have been identified in the ground-based image of Kirhakos et al. 1992 at 5.6'', 8.6'', and 9.0'' from the quasar. Additionally, Thimms (1995) has measured O II] emission using Fabry-Perot imaging at a redshift of 0.93, corresponding to the 8.6'' galaxy.
Post Thesis WorkChemical and multiphase ionization modeling has been done for all three systems.
See Churchill & Charlton (1999).
FOS/HST data have been investigated.
See Churchill et al. (2000a)
See Churchill et al. (2000b)
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