7338( 7) - 11/04/97 21:07 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7338 Version: 7 Check-in Date: 04-Nov-1997 21:05:54 1.Proposal Title: A study of the gravitational lensing potential in MG 0414+0534 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: EMILIO FALCO SMITHSONIAN ASTROPHYSICAL OBSERVATORY CoI: Brian McLeod Smithsonian Astrophysical Observatory N CoI: Joseph Lehar Harvard University N CoI: Christopher Kochanek Harvard University N CoI: Gordon Squires University of California Berkeley N ------------------------------------------------------------------------------------ 5. Abstract We proposed to use WFPC2 and NICMOS to observe the quadruple gravitational lens system MG 0414+0534, a QSO at z = 2.64 that is lensed by a single elliptical galaxy. However, we limit our plans to the 5 orbits that the TAC imposed for us to concentrate on NICMOS. We recently observed the system with HST and WFPC2/PC1 (Falco, Leh\'ar \& Shapiro 1997, AJ 112, 897; hereafter FLS96). We measured a light profile for the lens galaxy G, and discovered a blue arc connecting the 3 brightest images of the QSO. Although our elliptical single-potential lens models account qualitatively for all the properties of the system, they fail quantitatively, with fits that achieve only chi^2/N_dof ~ 5. Adding an independent shear axis allows a good fit to the data, but the physical source of such a shear remains to be determined. We intend to investigate whether the primary lens galaxy and its dark halo suffice to explain the observed lensing geometry or whether there are significant external tidal perturbations. We propose to use NICMOS to obtain a high- SNR determination of the brightness profile of the lens galaxy in the J, H and K bands. We would also obtain IR fluxes for the images that we would use to study extinction in this system, and to determine whether it originates in the lens galaxy or in the host galaxy of the lensed QSO. SAO proposal ID \# P3878-9-96 ------------------------------------------------------------------------------------ 7338( 7) - 11/04/97 21:07 - [ 2] Observations Description ------------------------ The lens galaxy will best be observed with NIC2 at F160W, the most sensitive band for detecting the lensing galaxy. We propose a 9600 sec exposure, which will reach an SNR/pix of 2 at the half-light radius of the galaxy. The half- light radius is 1\\arcs5, as determined by FLS96, and the I-H color of the galaxy is 3.5 (McLeod et al. 1997, in preparation). The combined image will be four times deeper than the existing F814W image of similar length. We estimate 4 orbits will be required. We also propose to use filters similar to J, H and K with NICMOS and NIC2 (and NIC1 in parallel), to investigate the sources of extinction along the line of sight. PLEASE NOTE: Our first visit consists of 4 orbits; we wish to dither onto 4 positions using SPIRAL-DITH with DITH- SIZE=0.4125, SAMP-SEQ=256, and NSAMP=21. We are thus trying to integrate as long as possible in each orbit. However, the total accumulation time of 2816 sec slightly exceeds the visibility in the first orbit, because of the required guide star acquisition. To attain the longest possible integrations in the last 3 orbits and still use a standard dither pattern, our plan is to allow the integration to extend into the obscuration (only in the first orbit, according to RPS2), and to just throw away the last accumulation in the first orbit from our analyses. That last accumulation would be useless for the first orbit, but the preceding and succeeding ones should be fine. We discussed our plan with Ray Lucas, and we agreed that because there is no consensus as yet at STScI, we would submit the proposal in accordance with our plan, but with the understanding that it might need modification if our plan might cause unexpected problems at the time of scheduling. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: ELECTRONIC Blocking Factor: 10 Ship To: Emilio E. Falco*Center for Astrophysics, MS 19*60 Garden St.*Cambridge, MA 02138 Ship Via: Email: falco@cfa.harvard.edu ------------------------------------------------------------------------------------ 7338( 7) - 11/04/97 21:07 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 MG0414+0534 GALAXY, GRAVITATIONAL RA=04H 14M 37.73S +/-0.06S, DEC= J2000 V = 20.00 LENS 5D 34' 44.3" +/-1.0", PLATE- V-I = 4.20 ID=002N Comments: RADIO COORDINATES, still some question at the 2" level, too faint to see in any DSS plate; Lensed image separation = 2.10", Lens galaxy V = 21.00 mag, 2 MG0414+0534- GALAXY, GRAVITATIONAL RA=04H 14M 37.73S +/-0.06S, DEC= J2000 V = 20.00 S LENS 5D 34' 41.47" +/-1.0", PLATE- V-I = 4.20 ID=002N Comments: Shifted from MG0414+0534 by (0",-2.83") (E,N) 7338( 7) - 11/04/97 21:07 - [ 4] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 101 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=19 , 1 DEF POS TARG -5.7 , -5.7 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 102 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG -5.5 , -2.1 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 103 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG -5.3 , 1.5 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 104 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG -5.1 , 5.1 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 105 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG -2.1 , -5.5 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 106 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=19 , 1 DEF POS TARG -1.9 , -1.9 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 107 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG -1.7 , 1.7 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 108 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=19 , 1 DEF POS TARG -1.5 , 5.3 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 109 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=19 , 1 DEF POS TARG 1.5 , -5.3 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 110 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG 1.7 , -1.7 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 111 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=19 , 1 DEF POS TARG 1.9 , 1.9 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 112 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG 2.1 , 5.5 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 113 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG 5.1 , -5.1 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 114 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=19 , 1 DEF POS TARG 5.3 , -1.5 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 115 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=18 , 1 DEF POS TARG 5.5 , 2.1 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 7338( 7) - 11/04/97 21:07 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 116 MG0414+0534 NIC2 MULTIAC NIC2-FI F160W SAMP-SEQ=STEP64,NSAMP=19 , 1 DEF POS TARG 5.7 , 5.7 CUM X PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 7338( 7) - 11/04/97 21:07 - [ 6] Visit: 02 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: We would like the H band exposures to be separate from the J and K, to prevent possible delays due to the uncertainties of K band scheduling => 2 visits. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 4 MG0414+0534 NIC2 MULTIAC NIC2-FI F110W SAMP-SEQ=STEP128,NSAMP=16, 1 DEF CUM X PATTERN=SPIRAL-DITH, DITH-SIZE=0.4125,NUM-POS=2 ------------------------------------------------------------------------------------------------------------------------------------ 7 MG0414+0534 NIC2 MULTIAC NIC2-FI F205W SAMP-SEQ=STEP64,NSAMP=13, 1 DEF -S CUM X PATTERN=YSTRIP-DITH, DITH-SIZE=5.66,NUM-POS=2, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 7338( 7) - 11/04/97 21:07 - [ 7] Summary Form for Proposal 7338 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMP-SEQ=STEP64 NSAMP=19 PATTERN=NONE NSAMP=18 NUM-POS=2 PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG -5.7 , -5.7 POS TARG -5.5 , -2.1 POS TARG -5.3 , 1.5 POS TARG -5.1 , 5.1 POS TARG -2.1 , -5.5 POS TARG -1.9 , -1.9 POS TARG -1.7 , 1.7 POS TARG -1.5 , 5.3 POS TARG 1.5 , -5.3 POS TARG 1.7 , -1.7 POS TARG 1.9 , 1.9 POS TARG 2.1 , 5.5 POS TARG 5.1 , -5.1 POS TARG 5.3 , -1.5 POS TARG 5.5 , 2.1 POS TARG 5.7 , 5.7 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160W F110W F205W ------------------------------------------------------------------------------------------------------------------------------------ Target Names MG0414+0534 MG0414+0534-S ------------------------------------------------------------------------------------------------------------------------------------