| |< | | < | | ^ | | > | | >| |
Q 1354+193
V = 16.0; z = 0.719; exp = 3600 s; coverage = 3765.8-6189.9 A
Optical spectra of this QSO have been studied by Weymann et al. (1979) and by SS92. Weymann et al. first reported a Mg II system at z = 0.457, which was confirmed at z = 0.4564 by SS92. A Lyman limit system roughly at this redshift with log N(HI) = 17.17 cm^-2 was reported by Bahcall et al (1993). The HIRES spectrum of this system has a relatively low signal to noise ratio, S/N ~20 per resolution element. This field has been studied in some detail and several galaxies in a cluster have been found by C. Steidel (private communication) and by K. Lanzetta (private communication) in this redshift range. However, there appears to be only a "single" Mg II system to a 5-sigma limit of EW(rest) ~0.03 A in the HIRES spectrum (there are no breaks in the redshift coverage until z = 0.82). It could be that the reported system is arising in multiple galaxy halos, though the profiles are not suggestive of kinematic complexity. High resolution spectra of high ionization transitions may be instrumental in a deeper appreciation of this line of sight.
z=0.456588 |DATA & VOIGT PROFILES| |EWs & AOD COLUMNS| |VP PARAMETERS|
This system is seen to have two subsystems separated by v ~80 km/s. The main subsystem is broad and exhibits hidden components, based upon the discrepancy of the N_a(v) profiles from the Mg II doublet. This is likely due to the low signal to noise, though it is interesting that the Fe II components are quite narrow, which may suggest that the system is comprised of many quiescent clouds. A total of seven VP components were fit, where the constraint on the cloud velocities was primarily the Mg II 2803 transition profile. The higher velocity subsystem has been fit with a single VP component. Mg I has been detected aligned with the strongest Mg II component. The Fe II 2600 transition was detected, but the spectrum is very noisy. The Fe II 2344, 2374, 2383, and 2587 transitions, the Mn II 2587 transition, and the Ca II 3934, 3969 doublet were not covered by the HIRES format. The other Mn II transitions show no absorption to the EW(rest) limits given in Table 3.43.
|PREVIOUS QSO| |NEXT QSO| | QSO LISTING | |TABLE OF CONTENTS| |CWC HOME|