6543( 6) - 02/03/99 13:54 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6543 Version: 6 Check-in Date: 03-Feb-1999 13:53:35 1.Proposal Title: EMISSION-LINE & CONTINUUM IMAGING OF THE GRAVITATIONAL LENS SYSTEM 2016+112 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 6 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Charles Lawrence California Institute of Technology CoI: R. D. Blandford California Institute of Technology N CoI: D. W. Hogg California Institute of Technology N CoI: D. P. Schneider Pennsylvania State University N CoI: J. T. Trauger Jet Propulsion Laboratoy N CoI: E. L. Turner Princeton University Observatory N ------------------------------------------------------------------------------------ 5. Abstract We propose to obtain images of the gravitational lens system 2016+112 in two broad filters and a narrow ramp filter centered on the strong, narrow Ly Alpha line of the z=3.265 multiply imaged quasar (5182 Angstrom, which by a happy coincidence can be placed on the PC with a 15degrees\ rotation). These observations will provide: 1) an accurate position of the faint third image relative to the others (not possible in radio images alone because of confusion with one of the lensing galaxies); 2) detections of or improved limits on additional images near the second lensing galaxy; 3) ellipticities and position angles for the two lensing galaxies; 4) evidence of any distortions in the quasar emission line regions on scales of less than 1 kpc; and, possibly, 5) a test of the existence of a cluster of galaxies at z~1 suggested by recent X-ray measurements; and 6) the structure of the resolved emission line regions located near the quasar. 2016+112 is the only known system with two supercritical lenses at different redshifts. Such systems may be quite sensitive to Omega_0. The proposed observations will provide crucial data required for a successful model. Stong radio emission from one of the lensing galaxies makes accurate and unambiguous radio-only measurements of the faint third image impossible. Only with high resolution HST images in the Ly Alpha line can this confusion be overcome. ------------------------------------------------------------------------------------ 6543( 6) - 02/03/99 13:54 - [ 2] Observations Description ------------------------ We propose observations in three filters. FR533N15 will be used to take images in the narrow Ly Alpha line at 5182 Angstrom. Broadband images through F606W will be used to subtract continuum emission from the narrowband images. Galaxies D and C are extremely red, and will be most detectable in F814W. begintabularllll FR533N15 & Primary Orbits: 8 & Exposures: 8 & PC1, F606W & Primary Orbits: 2 & Exposures: 2 & PC1, F814W & Primary Orbits: 2 & Exposures: 2 & WF, endtabular With FR533N15 (rotated by 15degrees), Ly Alpha at 5182 Angstrom\ falls on PC1 at pixel (699, 336). The total extent of 2016+112 is about 5", so it fits easily within a single strip on the filter. 2016+112 will be placed in at least two slightly different positions on PC1, so that ghosts or flaws associated with the narrow filter can be detected, and to verify placement in the bandpass of the filter. Eight orbits will give a SNR of 7 in the core pixels of C', or roughly 10 overall, high enough to determine accurate relative positions and to search for fainter images nearby. About 40\% of the light from images A, B, and C' (m_V~24.4 mag) in the F606W filter is from Ly Alpha. To obtain a SNR above 10 on the continuum level (highly desirable for subtraction of the continuum from the line image) as well as good cosmic ray discrimination requires two orbits. In two orbits with the F814W filter in the WF camera we estimate an average SNR ratio per pixel of 5 for galaxy C and 15 for galaxy D. Most of the light from C falls within a 1"\ circle, while D is larger. It should be possible, therefore, to determine a position angle and an ellipticity for both C and hboxD. Loss of positional accuracy on the unresolved components in the undersampled WF images will be minimized by shifting the pointing by n+1/2 pixels between the two exposures. It may also be enough to detect the possible cluster at z=1 suggested by the X-ray data. Only single exposures will be taken in each orbit. For objects this faint, the effect of read noise on split exposures in a single orbit is dramatic and bad. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 6543( 6) - 02/03/99 13:54 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 2016+112 GALAXY, GRAVITATIONAL RA=20H 19M 17.978S +/- 0.02S, J2000 Z=3.27 V = 22.2 LENS, QUASAR, RADIO DEC=11D 27' 13.10" +/- 0.2" I = 21.0 GALAXY Comments: never observed in B 6543( 6) - 02/03/99 13:54 - [ 4] Visit: 01 Visit Priority: Visit Requirements: PCS MODE F On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 2016+112 WFPC2 IMAGE LRF LRF 5182.0 ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. ------------------------------------------------------------------------------------------------------------------------------------ 2 2016+112 WFPC2 IMAGE LRF LRF 5182.0 ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. ------------------------------------------------------------------------------------------------------------------------------------ 3 2016+112 WFPC2 IMAGE LRF LRF 5182.0 ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. ------------------------------------------------------------------------------------------------------------------------------------ 4 2016+112 WFPC2 IMAGE LRF LRF 5182.0 ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. ------------------------------------------------------------------------------------------------------------------------------------ 5 2016+112 WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 SAME POS AS 1 Comments: THIS EXPOSURE SHOULD BE MADE WITH THE LRF APERTURE USED FOR EXPOSURES (1-4). NO TELESCOPE SLEW BETWEEN EXPOSURES 1-4 AND THIS EXPOSURE. ------------------------------------------------------------------------------------------------------------------------------------ 6 2016+112 WFPC2 IMAGE PC1-FIX F555W ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 SAME POS AS 1 Comments: THIS EXPOSURE SHOULD BE MADE WITH THE LRF APERTURE USED FOR EXPOSURES (1-4). NO TELESCOPE SLEW BETWEEN EXPOSURES 1-4 AND THIS EXPOSURE. ------------------------------------------------------------------------------------------------------------------------------------ 6543( 6) - 02/03/99 13:54 - [ 5] Visit: 02 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 7 2016+112 WFPC2 IMAGE LRF LRF 5182.0 ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 POS TARG -0.16,-0.16 Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation, BUT OFFSET -0.16,-0.16 FROM POSITION FOR EXPOSURES 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 8 2016+112 WFPC2 IMAGE LRF LRF 5182.0 ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 POS TARG -0.16,-0.16 Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. BUT OFFSET -0.16,-0.16 FROM POSITION FOR EXPOSURES 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 9 2016+112 WFPC2 IMAGE LRF LRF 5182.0 ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 POS TARG -0.16,-0.16 Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. BUT OFFSET -0.16,-0.16 FROM POSITION FOR EXPOSURES 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 10 2016+112 WFPC2 IMAGE LRF LRF 5182.0 ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 POS TARG -0.16,-0.16 Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. BUT OFFSET -0.16,-0.16 FROM POSITION FOR EXPOSURES 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 6543( 6) - 02/03/99 13:54 - [ 6] Visit: 03 Visit Priority: Visit Requirements: SAME ORIENT AS 2 GROUP 02-03 WITHIN 10 DAYS On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 2016+112 WFPC2 IMAGE WF3 F814W ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 Comments: SAME ORIENTATION AS 1-10, GROUP WITHIN 10 DAYS ------------------------------------------------------------------------------------------------------------------------------------ 12 2016+112 WFPC2 IMAGE WF3 F814W ATD-GAIN=7,CR-SPLIT=NO 1 2600.0 Comments: SAME ORIENTATION AS 1-10, GROUP WITHIN 10 DAYS ------------------------------------------------------------------------------------------------------------------------------------ 6543( 6) - 02/03/99 13:54 - [ 7] Summary Form for Proposal 6543 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures LRF PC1-FIX WF3 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN=7 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE F SAME POS AS 1 POS TARG -0.16,-0.16 SAME ORIENT AS 2 GROUP 02-03 WITHIN 10 DAYS ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements LRF F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 2016+112 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 5182.0 ------------------------------------------------------------------------------------------------------------------------------------