! Proposal 6543, submission 1 ! PI: C. R. Lawrence ! Received Thu Feb 8 20:39:58 EST 1996 ! From: vsm@grandpa.jpl.nasa.gov Proposal_Information ! Section 4 Title: EMISSION-LINE & CONTINUUM IMAGING OF THE GRAVITATIONAL LENS SYSTEM 2016+112 Proposal_Category: GO Scientific_Category: COSMOLOGY Cycle: 6 Investigators PI_name: C. R. Lawrence PI_Institution: Jet Propulsion Laboratory CoI_Name: R. D. Blandford CoI_Institution: California Institute of Technology CoI_Name: D. W. Hogg CoI_Institution: California Institute of Technology CoI_Name: D. P. Schneider CoI_Institution: Pennsylvania State University CoI_Name: J. T. Trauger CoI_Institution: Jet Propulsion Laboratoy CoI_Name: E. L. Turner CoI_Institution: Princeton University Observatory 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. Questions Observing_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. Calibration_Justification: Additional_Comments: Fixed_Targets Target_Number: 1 Target_Name: 2016+112 Alternate_Names: Description: GALAXY,GRAVITATIONAL LENS,QUASAR,RADIO GALAXY Position: RA=20H 19M 17.978S +/- 0.02S, DEC=11D 27' 13.10" +/- 0.2" Equinox: J2000 RV_or_Z: Z=3.27 Flux: V=22.2, I=21.0 Comments: never observed in B Visits 2 ! Section 6 Visit_Number: 01 Visit_Requirements: PCS MODE F ! Section 7.1 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 5182.0 Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. Exposure_Number: 2 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 5182.0 Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. Exposure_Number: 3 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 5182.0 Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. Exposure_Number: 4 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 5182.0 Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: Comments: POINTING AT CENTER OF 5182 ANGSTROM REGION ON PC, FR533N: 15-degrees rotation. Exposure_Number: 5 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: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. Exposure_Number: 6 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: 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. Visit_Number: 02 ! Section 6 Exposure_Number: 7 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 5182.0 Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: POS TARG -0.16,-0.16 ! Section 7.2 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 Exposure_Number: 8 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 5182.0 Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: POS TARG -0.16,-0.16 ! Section 7.2 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 Exposure_Number: 9 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 5182.0 Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: POS TARG -0.16,-0.16 ! Section 7.2 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 Exposure_Number: 10 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 5182.0 Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: POS TARG -0.16,-0.16 ! Section 7.2 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 Exposure_Number: 11 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F814W Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: Comments: Exposure_Number: 12 ! Section 6.5 Target_Name: 2016+112 Config: WFPC2 Opmode: IMAGE Aperture: WF3 Sp_Element: F814W Optional_Parameters: ATD-GAIN=7,CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 2600.0S Special_Requirements: Comments: Data_Distribution Medium: 8MM Ship_To: PI_Address Ship_Via: UPS