!   $Id: 6314,v 3.1 1995/06/08 11:31:08 pepsa Exp $
Proposal_Information
              Title: THE LEVEL OF IONIZATION AND CHEMICAL COMPOSITION OF QSO BAL
                     REGION GAS - REPEAT FOR HOPR 230

  Proposal_Category: GO
Scientific_Category: Quasars
              Cycle: 4

Investigators
        PI_Name: DAVID A. TURNSHEK
 PI_Institution: UNIVERSITY OF PITTSBURGH

       CoI_Name: BRIAN R. ESPEY
CoI_Institution: UNIVERSITY OF PITTSBURGH

       CoI_Name: RAY J. WEYMANN
CoI_Institution: MT WILSON & LAS CAMPANAS OBSERVATORY


Abstract:
FROM PROGRAM 5455:
About 10% of all radio quiet QSOs exhibit broad absorption lines (BALs) in
their spectra. The BALs come from a mostly highly ionized region outflowing
from the central source at speeds up to many tens of thousands of km/s.
Observational constraints on models require that the covering factor of the BAL
region be small (e.g., normally < 0.2), therefore many QSOs must have BAL
regions which do not lie along our lines-of-sight. For assumptions which
should reasonably apply to BAL regions, accurate (algorithm independent) ionic
column densities can be derived as a function of outflow velocity for BAL gas.
This is unlike the case for broad emission lines in QSOs, which at any observed
velocity originates in various components with a range of ionizations. Based on
column density analyses, evidence suggests that the chemical composition of the
BAL region gas is enhanced by factors of 10 to 100 or more times solar values.
Since this conclusion is remarkable, we propose to carefully checked it. One
possible problem is that our assumptions about the ability of BAL gas to cover
the central source are not universally correct. Another problem with past
analyses is that different ionic species of the same element in an object have
not been studied. We will remedy these problems by observing the UV spectrum of
three specially selected BAL QSOs which currently show the best evidence for
enhanced abundances. Constraints on the ionization and chemical composition of
the BAL region gas will be derived using Ferland's photoionization code.


Questions

Observing_Description:
FROM PRGRAM 5455:
We propose HST observations of 4 QSOs using the FOS G270H mode in order to
study the strength and shape of BAL profiles that fall in the spectral region
below 3200 Angstroms. The observation of each object can be made during a
single visit. The signal-to-noise ratio attained near continuum regions will be
approximately 30 per resolution element with resolution R=1300 (4 pixels per
resolution element with 1/4 diode substeps).  Exposure times range from 34
minutes to 54 minutes. In addition we will observe 6 QSOs using the FOS G160L
mode in order to follow the shapes of the continuous energy distributions
into the far UV. The signal-to-noise ratio attained near continuum regions
at about 1600 Angstroms will be 10 per resolution element with resolution
R=200 (4 pixels per resolution element with 1/4 diode substeps), which will
be adequate for our purpose.
THIS PROGRAM REPEATS 1 FAILED OBSERVATION FROM PROGRAM 5455.


Fixed_Targets
  Target_Number: 4
    Target_Name: Q0932+5006
    Description: GALAXY, QSO, Radio Quiet
       Position: RA = 9H 35M 53.01S +/- .1S,
                 DEC = +49D 53' 13.8" +/- .1S,
                 PLATE-ID=00T8
        Equinox: 2000
        RV_or_Z: Z = 1.92
           Flux: V = 17.24
                 B-V = 0.16
                 F-CONT(1600) = 8.6 E-16
       Comments: PREVIOUSLY OBSERVED WITH HST


Visits
      Visit_Number: 1

     Exposure_Number: 7
         Target_Name: Q0932+5006
              Config: FOS/RD
              Opmode: ACQ/BINARY
            Aperture: 4.3
          Sp_Element: MIRROR
Number_of_Iterations: 1
   Time_Per_Exposure: 14.6S
Special_Requirements: ONBOARD ACQ FOR 8

     Exposure_Number: 8
         Target_Name: Q0932+5006
              Config: FOS/RD
              Opmode: ACCUM
            Aperture: 1.0
          Sp_Element: G160L
Number_of_Iterations: 1
   Time_Per_Exposure: 20M


Data_Distribution

         Medium: 8MM             ! 8MM or 6250BPI or 1600BPI
Blocking_Factor: 10              ! 10 or 1
        Ship_To: PI_Address      ! STSCI or PI_Address or <free-text>
       Ship_Via: UPS             ! UPS (2-day) or OVERNIGHT