! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 5816,v 1.1 1994/12/14 19:48:19 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: n/a ! Phone: n/a , E-mail: n/a ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: tytler-556.prop ! Date generated: Wed Dec 14 14:48:07 EST 1994 ! Proposal_Information ! Section 4 Title: Archival Search for METAL LINES in QUASAR LYMAN-ALPHA SYSTEMS Proposal_Category: AR Scientific_Category: Quasars Cycle: 5 Investigators PI_name: Prof. David Tytler PI_Institution: University of California, San Diego CoI_Name: Xiao-Ming Fan CoI_Institution: University of California, San Diego Contact: ! Y or N (designate at most one contact) CoI_Name: Scott Burles CoI_Institution: University of California, San Diego Contact: ! Y or N (designate at most one contact) CoI_Name: Christopher Davis CoI_Institution: University of California, San Diego Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) QSO Lyman-alpha forest absorption systems have traditionally been considered intergalactic primordial gas clouds, but new data suggest that many of them at high redshift contain metals with abundances of C/H ~eq -3, which means 10^-3 solar. We propose to search for metals in HST spectra of LyAlpha forest systems at low redshift. The search has two parts: first we look for 2 Sigma metal lines at the expected positions of known LyAlpha lines, and we estimate the number of chance identifications. Second, we align and coadd spectra at the expected positions of the metal lines in each LyAlpha systems. We will look for the strong metal lines (C IV, O VI, N V, C III, Mg X and Ne VIII) in this composite. There are five reasons why we expect to find metals. (1) We are finding C IV in LyAlpha clouds at high z. (2) The number of C IV systems increases with decreasing redshift. (3) In general, abundances should be higher at low z. (4) We are now identifying many low redshift LyAlpha lines with the outer regions of galaxies. (5) O VI should be stronger than C IV. O VI is not easily seen at high z because of confusion in the LyAlpha forest, but it will be accessible in HST data. With 100 LyAlpha systems from the HST spectra of 167 QSOs we should reach a limit of C/H <= -2.3 for C IV, and worse for other ions. If we find metals, we begin to determine if they are more common in LyAlpha clouds which are associated with galaxies, and especially whether they occur in clouds which are intergalactic. Questions ! Free format text (please update) Observing_Description: Real_Time_Justification: Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: Target_Name: Alternate_Names: Description: Position: ! Most common specification format is ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: ! Include at least V and B-V Comments: Solar_System_Targets ! Section 5.2 Target_Number: Target_Name: Description: Level_1: ! Satellite of Sun Level_2: ! Satellite of Level_1 Level_3: ! Satellite of Level_2 Window: Flux: ! Include at least V and B-V Comments: Generic_Targets ! Section 5.3 Target_Number: Target_Name: Description: Criteria: Flux: Comments: Scan_Data ! Appendix B Scan_Number: FGS_Scan: Cont_or_Dwell: Dwell_Points: Dwell_Secs: Scan_Width: Scan_Length: Sides_Angle: Number_Lines: Scan_Rate: First_Line_PA: Scan_Frame: Length_Offset: Width_Offset: ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed Visits ! Section 6 Visit_Number: Visit_Requirements: ! Section 7.1 ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling ! PCS MODE [Fine | Gyro] ! GUIDing TOLerance ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN