! !__Proposal-Section__ !6156 ! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 6156,v 3.1 1995/06/22 19:32:45 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: Christian Ready ! Phone: 410 338-4546 , E-mail: ready@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: new-prop.file.prop ! Date generated: Tue Mar 21 17:29:03 EST 1995 ! Proposal_Information ! Section 4 Title: Is the intergalactic HeII absorption in PKS 1935-692 and Q0302-003 truly different? Proposal_Category: GO/DD Scientific_Category: Quasars Cycle: 5 Investigators PI_name: Peter Jakobsen PI_Institution: Astrophysics Division, ESA/ESTEC CoI_Name: David Tytler CoI_Institution: University of California, San Diego Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) Follow-up FOC far-UV objective prism observations of the second example of a ``clear'' high redshift quasar ever to be discovered, the z=3.18 object PKS 1935-692 will be made. An earlier FOS observation of this object suggests that PKS 1935-692 displays considerably less intense intergalactic helium foreground absorption than that previously detected in the FOC prism spectrum of Q0302-003 at z=3.29. This implies that the helium opacity may be patchy at z~3 and that universe was in the process of becoming re- ionized in helium at that late epoch. The objective of the proposed observation is to verify this important finding by exploiting the superior background monitoring and subtraction afforded by the two dimensional FOC detector and enable a clean and unambiguous comparison of the HeII absorption in PKS 1935-692 and Q0302-003 to be made. Questions Observing_Description: Based on our considerable experience with the FOC far-UV prism, we have developed a simple, but effective, observing strategy that involves limiting individual FOC prism exposures of faint targets to about 20 minute duration and co-adding the individually reduced exposures. Aside from enabling variations in the the particle and sky background to be dealt with in an optimal manner, this technique also has the important benefit of allowing the individual sub- spectra to be shifted slightly on the FOC detector through offset pointing (by a few tenths of an arcsecond) in order to eliminate residual flat-field effects in the resulting combined spectrum. Assuming a visibility of 59 minutes for PKS 1935-692, it follows that two 20-25 minute sub- exposures are achievable per orbit and that a total of 5 orbits are required to reach the desired total exposure time of 1.5 * 10^4 s. All exposures are blind ``point and shoot'' (Mode III) and no special calibration exposures are required beyond routine Cycle 5 calibrations. Real_Time_Justification: None None Calibration_Justification: Additional_Comments: Fixed_Targets Target_Number: 1 Target_Name: Q1935-692 Alternate_Names: Description: GALAXY, QUASAR Position: RA = 19H 40M 25.56S +/- 0.1S, DEC = -69D 07' 56.5" +/- 1", PLATE-ID=01CB Equinox: J2000 RV_or_Z: Z=3.152 Flux: V = 18.8 +/- 0.5 ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed Visits ! Section 6 Visit_Number: 1 Visit_Requirements: ! Section 7.1 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1100S Special_Requirements: POS TARG +0.0,-4.9 Exposure_Number: 2 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1100S Special_Requirements: POS TARG -0.2,-4.9 Exposure_Number: 3 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1400S Special_Requirements: POS TARG +0.2,-4.9 Exposure_Number: 4 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1400S Special_Requirements: POS TARG +0.2,-4.7 Exposure_Number: 5 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1400S Special_Requirements: POS TARG +0.0,-4.7 Exposure_Number: 6 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1400S Special_Requirements: POS TARG -0.2,-4.7 Exposure_Number: 7 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1400S Special_Requirements: POS TARG -0.2,-5.1 Exposure_Number: 8 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1400S Special_Requirements: POS TARG +0.0,-5.1 Exposure_Number: 9 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1400S Special_Requirements: POS TARG +0.2,-5.1 Exposure_Number: 10 Target_Name: Q1935-692 Config: FOC/96 Opmode: IMAGE Aperture: 512x512 Sp_Element: PRISM1 Wavelength: 1150-6000 Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 1400S Special_Requirements: POS TARG +0.1,-4.9 Data_Distribution ! Defaults indicated; change if desired Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 ! Only astronomers with very old 9- ! track tape drives should consider ! a blocking factor of 1 Ship_To: PI_Address ! STSCI or PI_Address or ! PI Address from Phase I is: ! ! 2200 AG Noordwijk ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: ! Needed if Ship_To: is not PI_Address ! ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator