! This version is the one involving simple two-point dithers of 0.25,0.25 ! arcsec for ~half the exposures in both WF3-FIX and PC1-FIX. The other ! half are done at the default aperture position of POS TARG 0,0. This ! corresponds to the file that RAL tested that yielded the most exposure ! time while still staying within the maximum exposure times desired and ! still dithering. - It corresponds to the file I called andyv5_5937.prop ! during testing. A similar version was tried in which the positions were ! kept the same while the filters were switched, but this version yielded ! more exposure time on target. - RAL 6 Sept., 1995 ! ! Uses POS TARGS for all dithering ! Proposal 5937, submission 1 ! PI: Edwin L. Turner ! Received Mon Feb 27 11:04:52 EST 1995 ! From: elt@astro.Princeton.EDU ! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 5937,v 4.1 1995/09/08 15:21:41 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: Ray Lucas ! Phone: 410 338-4716 , E-mail: lucas@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Date generated: Sat Dec 17 10:53:31 EST 1994 ! Proposal_Information Title: A Gravitational Lens Telescope: Ly-Alpha Imagery of Q2237+0305 Proposal_Category: GO Scientific_Category: Quasars Cycle: 5 Investigators PI_name: Edwin L. Turner PI_Institution: Princeton University Observatory CoI_Name: Joachim Wambsganss CoI_Institution: Max-Planck Institute for Astrophysics Contact: N Abstract: Q2237+0305, aka Huchra's lens or Einstein's cross, is one of the best understood gravitational lens systems, in part because the lensing galaxy is unusually nearby (z=0.04). The continuum emitting core of the z=1.69 quasar which is the background source lies only about 0.1 arcsec from perfect alignment directly behind the galaxy, and its images (which fall about 1 arcsec from the center of the galaxy) are magnified by factors at least of order 10. Any emission in the region near the quasar core will also be strongly magnified. Such emission would be resolved from the core images by HST even if it were as small as 50h^-1 parsec (0.01 arcsec intrinsic angular size). We propose to obtain deep WFPC2 images in the F336W and F300W bands which are fortuitously well matched to the redshifted Ly-Alpha emission line of the source. Such emission can be mapped back into the source plane (via available models of the system) to provide a map of the HII region surrounding the quasar at otherwise inaccessible resolution. In addition, Ly-Alpha emission regions in the quasar's host galaxy may be detected with some degree of lensing boost (depending on its location relative to the quasar core), probably with characteristic distorted arc- like shapes. Reversing the problem, resolved emission will also provide additional, potentially powerful constraints on lens models of Q2237+0305 and thus further constrain the galaxy's mass distribution. Questions Observing_Description: We wish to obtain images through both F336W (the Ly-alpha band) and F300W (the reference band for dust and other broadband features) using both the PC chip (for subtraction of the core images to look for relatively high surface brightness resolved features very near the core images) and a WF chip (to look for lower surface brightness emission well separated from the core images). We propose to devote 2 orbits to each type of chip with F300W and 3 orbits each with F336W for a total of 10 orbits. The criterion for individual exposure times is to avoid bleeding of the core images in the WF exposures and to keep the core images well within the linear range in the PC exposures so that they may be accurately subtracted. Unfortuantely, in this context (but not others!), the core images of Q2237+0305 are quite variable due to microlensing events and perhaps intrinsic fluctuations, so that it is not possible to predict their brightnesses in advance. We have, therefore, used predictions of their rough typical brightnesses based on Yee's photometry (extrapolated by the observed spectral index, -1.5, into the UV) and then allowed fairly generous safety margins to absorb microlensing or other variations. Based on these calculations we adopt individual WF exposures of 17 to 21 minutes each and individual PC exposures of 11 to 13 minutes. After ``orbit packing" calculations, we find that this plan gives totals of 126 minutes in 6 exposures for WF chip with F336W, 76 minutes in 4 exposures for WF chip with F300W, 112 minutes in 9 exposures for PC chip with F336W, and 78 minutes in 6 exposures for PC chip with F300W. Real_Time_Justification: None. Calibration_Justification: None. Additional_Comments: None. Fixed_Targets Target_Number: 1 Target_Name: G2237+0305 Alternate_Names: EINSTEIN CROSS, HUCHRA'S LENS Description: GALAXY, GRAVITATIONAL LENS, QSO, SPIRAL Position: RA = 22H 40M 29.78S +/- 0.06S, DEC = +3D 21' 29.4" +/- 1" Equinox: J2000 RV_or_Z: Z = 1.69 Flux: V = 17.5 +/- 1.5 B-V = 0.5 +/- 1.0 Comments: FLUX VALUES ARE NOT AVAILABLE IN THE UV WHERE WE ARE IMAGING. ALSO, MICROLENSING EVENTS PRODUCE STRONG IMAGE VARIATIONS AND THERE IS EVIDENCE FOR EXTINCTION BY DUST IN THE LENS. THE FLUX OF THE LY-ALPHA FEATURES FOR WHICH WE ARE SEARCHING IS ENTIRELY UNKNOWN. SEE OBSERVING_DESCRIPTION ABOVE FOR STRATEGY. Visits Visit_Number: 1 Visit_Requirements: Exposure_Number: 1 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1100S Special_Requirements: POS TARG 0,0 ! MAX DUR 1100S Exposure_Number: 2 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1100S Special_Requirements: POS TARG 0,0 ! MAX DUR 1100S Exposure_Number: 3 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1300S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 1300S Exposure_Number: 4 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1300S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 1300S Exposure_Number: 5 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1100S Special_Requirements: POS TARG 0,0 ! MAX DUR 1300S Exposure_Number: 6 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1200S Special_Requirements: POS TARG 0,0 ! MAX DUR 1300S Exposure_Number: 7 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1200S Special_Requirements: POS TARG 0,0 ! MAX DUR 1300S Exposure_Number: 8 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1100S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 1300S Exposure_Number: 9 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1200S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 1300S Exposure_Number: 10 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: WF3-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 1200S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 1300S Visit_Number: 2 Visit_Requirements: SAME ORIENT AS 1 Exposure_Number: 11 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0,0 ! MAX DUR 700S Exposure_Number: 12 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0,0 ! MAX DUR 700S Exposure_Number: 13 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0,0 ! MAX DUR 700S Exposure_Number: 14 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 800S Special_Requirements: POS TARG 0,0 ! MAX DUR 800S Exposure_Number: 15 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0,0 ! MAX DUR 800S Exposure_Number: 16 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 800S Exposure_Number: 17 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 800S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 800S Exposure_Number: 18 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 800S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 800S Exposure_Number: 19 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F336W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 800S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 800S Exposure_Number: 20 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0,0 ! MAX DUR 800S Exposure_Number: 21 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 800S Special_Requirements: POS TARG 0,0 ! MAX DUR 800S Exposure_Number: 22 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0,0 ! MAX DUR 800S Exposure_Number: 23 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 800S Exposure_Number: 24 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 800S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 800S Exposure_Number: 25 Target_Name: G2237+0305 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F300W Optional_Parameters: CR-SPLIT = NO Number_of_Iterations: 1 Time_Per_Exposure: 800S Special_Requirements: POS TARG 0.25,0.25 ! MAX DUR 800S 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: ! ! 137 Peyton Hall,Ivy Lane, ! Princeton, NJ 08544-1001 ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: ! Needed if Ship_To: is not PI_Address !