10109( 3) - 06/11/04 14:45 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10109 Version: 3 Check-in Date: 11-Jun-2004 18:41:36 1.Proposal Title: The Distance and Mass of the Neutrino-Luminous White Dwarf PG 0122+200 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. M. Sean O'Brien Yale University CoI: Dr. Howard E. Bond Space Telescope Science Institute N CoI: Dr. Edmund Nelan Space Telescope Science Institute N ------------------------------------------------------------------------------------ 6. Abstract PG 0122+200 is a pulsating hot white dwarf that is believed to radiate more energy as neutrinos than it does as photons. We propose to measure with FGS the trigonometric parallax of PG 0122+200 and thereby determine its distance, luminosity, and mass. Ongoing investigations from the ground will infer the neutrino luminosity through its effect on the pulsation periods, thus testing standard and non-standard lepton theory, but the stellar mass must first be known. The pulsation spectrum of PG 0122+200 admits two alternative seismological interpretations, each implying a different mass, luminosity, and distance. Measurement of an accurate distance will resolve the matter once and for all and precisely determine the stellar mass. This project represents the first test of lepton physics in dense (log rho = 6) plasma and is relevant to the many areas of stellar physics in which neutrino interactions are important, including recent theories intended to solve the solar-neutrino problem. ------------------------------------------------------------------------------------ 10109( 3) - 06/11/04 14:45 - [ 2] Observations Description ------------------------ The proposed observations consist of astrometric measurements of PG 0122+200, along with about half a dozen reference stars surrounding it. The target will be observed with FGS1R at five epochs of maximum parallax factor, i.e., at 6, 12, 18, and 24 months after the initial observation. At each epoch we will observe the target and its reference field during two HST visits separated by about two weeks. Each one-orbit visit will consist of repeated measurements of our science target and the reference stars in the field of view. This will yield the relative positions of the stars for the visit and allow us to define the visit's "plate." The 24-month baseline will allow a robust determination of the proper motions of the targets, an essential ingredient in the parallax solution. Once the observations from all 5 epochs have been completed, the observations will be combined with a "plate-overlay" technique to define a common reference frame (a "virtual plate") onto which the positions of the individual stars can be mapped. By comparing the position of the science target to the reference frame in the 10 independent observations obtained during the 5 epochs, we can solve for both the proper motion and the trigonometric parallax of the object, relative to the comparison stars. Our request is thus for 10 orbits (5 visits 2 orbits per visit). This is a Long-Term proposal, since the observations must extend 24 months past the first visit. We request 4 orbits in Cycle 12, 4 in Cycle 13, and 2 in Cycle 14. The derived FGS parallaxes will, of course, be relative to the reference frame of the fainter surrounding stars. In order to convert the relative parallax to absolute with the highest accuracy, we need an estimated parallax of each individual reference star. We therefore plan to obtain photometry and spectroscopy of each of the reference stars and determine spectroscopic parallaxes for them. We are applying herewith (see the Coordinated Observations section below) for the modest amount of NOAO observing time needed to obtain the data for the spectroscopic parallaxes of the reference stars. FGS3, the original FGS used for HST astrometry, was capable of excellent parallax accuracy. For example, based on a series of FGS3 observations obtained in 1995-97, Benedict et al. (2002a, b) obtained absolute parallax accuracies of ?0.15 and ?0.20 mas for Cep and RR Lyr, respectively. For comparison, the Hipparcos accuracies for the same stars were ?0.58 and ?0.59 mas. FGS1R, installed in 1997, has replaced FGS3 as the "astrometry" FGS. The performance of FGS1R should exceed that of FGS3 for two reasons. (1) FGS1R displays a temporal stability of its interferograms never achieved by FGS3, an attribute that greatly improves the measurement repeatability. (2) FGS1R benefits from a more robust calibration program. In particular, the observing technique employed to calibrate its geometric distortions (the dominant source of astrometric error) has resulted in residuals that are about 1/3 those of FGS3. The instrument's lateral color and cross-filter calibrations are also better characterized. Indications of FGS1R's excellent performance are becoming available. A recently completed program (McGrath et al. 2002) used FGS1R to search for the astrometric wobble of rho-1 Cnc due to its planetary companion. Fourteen orbits of FGS data were taken near one epoch of maximum parallax factor to search for the short-period wobble. To determine the proper motion and parallax, one additional orbit each was used 6 and 12 months later, so that the parallax error budget is essentially that of a 3-orbit program. Our team member Nelan, who is the STScI FGS Instrument Scientist, designed the observing strategy, and has done an unpublished analysis of the rho-1 Cnc parallax. The result shows a 1-sigma parallax error of ?0.4 mas. We thus adopt ?0.4 mas as 10109( 3) - 06/11/04 14:45 - [ 3] the error in an FGS1R parallax based on three one-orbit HST visits at 6-month intervals. This error can be reduced to ?0.4/(n/3)^1/2 mas, where n is the number of HST orbits, down to a systematic-error floor that we estimate to be < 0.15 mas. These considerations suggest that FGS1R should be able to measure the relative parallax of PG 0122+200 with an accuracy of at least 0.2 mas based on 10 HST orbits over the next three scheduling cycles. Benedict, G.F. et al. 2002a, AJ, 123, 473 Benedict, G.F. et al. 2002b, AJ, 124, 1695 McGrath, M.A. et al. 2002, ApJ, 564, L27 Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10109( 3) - 06/11/04 14:45 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PG0122+200 EXT-STAR, PG1159 STAR RA=01H25M22.48S +/- 0.5", J2000 V = 16.5+/-0.2 DEC=+20D17'56.94" +/- 0.5", PLATE-ID=021K Coordinate Source: GUIDE_STAR_CATALOG 2 REF1 CALIBRATION, RA=01H25M20.48S +/- 0.1", J2000 V = 14.0+/-0.2 ASTROMETRIC DEC=+20D17'53.05" +/- 0.1", PLATE-ID=021K Coordinate Source: GUIDE_STAR_CATALOG 4 REF3 CALIBRATION, RA=01H25M40.2S +/- 0.1", J2000 V = 14.9+/-0.2 ASTROMETRIC DEC=+20D19'10.88" +/- 0.1" Coordinate Source: GUIDE_STAR_CATALOG 5 REF4 CALIBRATION, RA=01H25M51.0S +/- 0.1", J2000 V = 13.6+/-0.2 ASTROMETRIC DEC=+20D19'59.16" +/- 0.1" Coordinate Source: GUIDE_STAR_CATALOG 6 REF5 CALIBRATION, RA=01H25M40.01S +/- 0.1", J2000 V = 15.3+/-0.2 ASTROMETRIC DEC=+20D16'50.12" +/- 0.1", PLATE-ID=021K Coordinate Source: GUIDE_STAR_CATALOG 7 REF6 CALIBRATION, RA=01H25M32.1S +/- 0.1", J2000 V = 14.6 ASTROMETRIC DEC=+20D16'24.02" +/- 0.1", PLATE-ID=021K Coordinate Source: GUIDE_STAR_CATALOG 8 REF7 CALIBRATION, RA=01H25M25.95S +/- 0.1", J2000 V = 14.1+/-0.2 ASTROMETRIC DEC=+20D16'20.5" +/- 0.1", PLATE-ID=021K Coordinate Source: GUIDE_STAR_CATALOG 10109( 3) - 06/11/04 14:45 - [ 5] Visit: 01 Visit Priority: Visit Requirements: PCS MODE FINE; SCHED 50%; ORIENT 249.0D TO 255.0 D; BETWEEN 10-JUL- 2004:00:00:00 AND 13-JUL-2004:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PG0122+200 FGS POS 1 F583W 1 45 S POS TARG -99,-55; SEQ 1-14 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 4 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 5 REF5 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 6 PG0122+200 FGS POS 1 F583W 1 45 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 7 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 8 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 9 REF3 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 10 REF4 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 11 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 12 PG0122+200 FGS POS 1 F583W 1 45 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 13 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 14 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 1 none none none none 1 tbd 01 2 none none none none 1 tbd 01 3 none none none none 1 tbd 01 4 none none none none 1 tbd 01 5 none none none none 1 tbd 10109( 3) - 06/11/04 14:45 - [ 6] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 6 none none none none 1 tbd 01 7 none none none none 1 tbd 01 8 none none none none 1 tbd 01 9 none none none none 1 tbd 01 10 none none none none 1 tbd 01 11 none none none none 1 tbd 01 12 none none none none 1 tbd 01 13 none none none none 1 tbd 01 14 none none none none 1 tbd 10109( 3) - 06/11/04 14:45 - [ 7] Visit: 02 Visit Priority: Visit Requirements: PCS MODE FINE; SCHED 50%; ORIENT 249.0D TO 255.0 D; AFTER 01 BY 1 D TO 3 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PG0122+200 FGS POS 1 F583W 1 45 S POS TARG -99,-55; SEQ 1-14 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 REF1 FGS POS 1 F583W 1 15 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 4 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 5 REF5 FGS POS 1 F583W 1 15 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 6 PG0122+200 FGS POS 1 F583W 1 45 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 7 REF1 FGS POS 1 F583W 1 15 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 8 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 9 REF3 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 10 REF4 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 11 REF5 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 12 PG0122+200 FGS POS 1 F583W 1 45 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 13 REF1 FGS POS 1 F583W 1 15 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 14 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 02 1 none none none none 1 tbd 02 2 none none none none 1 tbd 02 3 none none none none 1 tbd 02 4 none none none none 1 tbd 02 5 none none none none 1 tbd 02 6 none none none none 1 tbd 10109( 3) - 06/11/04 14:45 - [ 8] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 02 7 none none none none 1 tbd 02 8 none none none none 1 tbd 02 9 none none none none 1 tbd 02 10 none none none none 1 tbd 02 11 none none none none 1 tbd 02 12 none none none none 1 tbd 02 13 none none none none 1 tbd 02 14 none none none none 1 tbd 10109( 3) - 06/11/04 14:45 - [ 9] Visit: 03 Visit Priority: Visit Requirements: PCS MODE FINE; SCHED 30%; ORIENT 68.5D TO 69.0 D; BETWEEN 05-JAN- 2005:00:00:00 AND 10-JAN-2005:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PG0122+200 FGS POS 1 F583W 1 45 S POS TARG 95, 40; SEQ 1-15 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 4 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 5 REF5 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 6 PG0122+200 FGS POS 1 F583W 1 45 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 7 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 8 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 9 REF3 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 10 REF4 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 11 REF5 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 12 PG0122+200 FGS POS 1 F583W 1 45 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 13 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 14 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 15 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 03 1 none none none none 1 tbd 03 2 none none none none 1 tbd 03 3 none none none none 1 tbd 10109( 3) - 06/11/04 14:45 - [ 10] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 03 4 none none none none 1 tbd 03 5 none none none none 1 tbd 03 6 none none none none 1 tbd 03 7 none none none none 1 tbd 03 8 none none none none 1 tbd 03 9 none none none none 1 tbd 03 10 none none none none 1 tbd 03 11 none none none none 1 tbd 03 12 none none none none 1 tbd 03 13 none none none none 1 tbd 03 14 none none none none 1 tbd 03 15 none none none none 1 tbd 10109( 3) - 06/11/04 14:45 - [ 11] Visit: 04 Visit Priority: Visit Requirements: PCS MODE FINE; SCHED 30%; ORIENT 68.5D TO 69.0 D; AFTER 03 BY 3 D TO 6 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PG0122+200 FGS POS 1 F583W 1 45 S POS TARG 95, 40; SEQ 1-15 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 3 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 4 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 5 REF5 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 6 PG0122+200 FGS POS 1 F583W 1 45 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 7 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 8 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 9 REF3 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 10 REF4 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 11 REF5 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 12 PG0122+200 FGS POS 1 F583W 1 45 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 13 REF1 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 14 REF7 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 15 REF6 FGS POS 1 F583W 1 10 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 04 1 none none none none 1 tbd 04 2 none none none none 1 tbd 04 3 none none none none 1 tbd 04 4 none none none none 1 tbd 10109( 3) - 06/11/04 14:45 - [ 12] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 04 5 none none none none 1 tbd 04 6 none none none none 1 tbd 04 7 none none none none 1 tbd 04 8 none none none none 1 tbd 04 9 none none none none 1 tbd 04 10 none none none none 1 tbd 04 11 none none none none 1 tbd 04 12 none none none none 1 tbd 04 13 none none none none 1 tbd 04 14 none none none none 1 tbd 04 15 none none none none 1 tbd 10109( 3) - 06/11/04 14:45 - [ 13] Summary Form for Proposal 10109 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations FGS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes POS ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE; SCHED 50%; ORIENT 249.0D TO 255.0 D; BETWEEN 10-JUL-2004 00 00 00 AND 13-JUL-2004 00 00 00 POS TARG -99,-55; SEQ 1-14 NON-INT SAME POS AS 1 PCS MODE FINE; SCHED 50%; ORIENT 249.0D TO 255.0 D; AFTER 01 BY 1 D TO 3 D PCS MODE FINE; SCHED 30%; ORIENT 68.5D TO 69.0 D; BETWEEN 05-JAN-2005 00 00 00 AND 10-JAN-2005 00 00 00 POS TARG 95, 40; SEQ 1-15 NON-INT PCS MODE FINE; SCHED 30%; ORIENT 68.5D TO 69.0 D; AFTER 03 BY 3 D TO 6 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F583W ------------------------------------------------------------------------------------------------------------------------------------ Target Names PG0122+200 REF1 REF7 REF6 REF5 REF3 REF4 ------------------------------------------------------------------------------------------------------------------------------------