12980( 21) - 20-Feb-2014 15:21:33 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12980 Version: 21 Check-in Time: 20-Feb-2014 15:21:33 STScI Edit Number: 17 Title Absolute Measurement of the Cosmic Near-Infrared Background Using Eclipsed Galilean Satellites as Occulters ------------------------------------------------------------------------------------ Type Cycle GO 20 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Kohji Tsumura ISAS, Japan Aerospace Exploration Agency Y CoI: Dr. Jason A. Surace California Institute of Technology N CoI: Dr. Eiichi Egami University of Arizona N CoI: Dr. Mai Shirahata ISAS, Japan Aerospace Exploration Agency N CoI: Mr. Ko Arimatsu ISAS, Japan Aerospace Exploration Agency N CoI: Dr. Shuji Matsuura ISAS, Japan Aerospace Exploration Agency N CoI: Dr. Takayuki Kotani National Astronomical Observatory of Japan N (NAOJ) CoI: Mr. Fumihiko Usui ISAS, Japan Aerospace Exploration Agency N CoI: Dr. Takehiko Wada ISAS, Japan Aerospace Exploration Agency N CoI: Mr. Toshiaki Arai ISAS, Japan Aerospace Exploration Agency N ------------------------------------------------------------------------------------ Abstract The Cosmic Infrared Background (CIB) as an integrated history of the early universe is important for the study of the Dark Ages, and it may include the light from the first stars at z~10. However, previous CIB measurements suffer from residual contamination from strong foreground emission (e.g. the zodiacal light). We propose to observe two Galilean satellites eclipsed in the shadow of Jupiter as occulting disks at near-infrared wavelengths in order to detect the absolute CIB intensity without any zodiacal light subtraction error. The zodiacal light originates inside the orbit of Jupiter; since the Galilean satellites in eclipse shield all light beyond the Jovian orbit, they should be detected as 'dark spots' if the strong CIB implied by previous observations exists. The intensity deficit of this dark spot relative to the surrounding sky directly measures the strength of the CIB, free from any assumptions about the zodiacal light. The size of the dark spot is approximately 1 arcsec in diameter and the predicted surface brightness is 70 nW/m2/sr lower than that of surrounding sky brightness, which can be detected by WFC3 IR imaging with F140W filter for two orbits integration with S/N=10 even in the strong Jovian stray light environment. ------------------------------------------------------------------------------------ Observations Description ------------------------ The greatest difficulty in this observation results from scattered light due to the close proximity of Jupiter to the target satellites (< 80 arcseconds). According to our estimation, leak energy from encircled energy at 30 arcsec is 0.04%, and Jovian stray light at 30 arcsec is about 5 times brighter than the zodiacal light. Therefore, we will keep Jupiter out of the detector field of view (FoV) during the observation to avoid stray light from Jupiter (Jupiter is 20 magnitudes brighter than the eclipsed satellites). Observations will be conducted with non-sidereal tracking on Jupiter (outside of the FoV) to fix the stray light pattern on the detector array during the observation. This will 12980( 21) - 20-Feb-2014 15:21:33 - [ 2] minimize the systematic error of the Jovian stray light. Since the relative speed of the target satellites vs. Jupiter is ~0.005 arcsec/sec, we use an observing mode of SPARS=25 and NSAMP=14. In this case, the image of target satellite will be smeared because of its movement and non-destructive readouts of the detecter. Therefore, we will reconstruct the image by calculating [Nth - (N-1)th] frames and conducting the "shift and add". Letting the eclipsed satellite move relative to the detector using Jupiter tracking has the advantage of effectively dithering the observations so that we can average out any detector issues such as scattered earthlight, structure in the darks, and the dark features called "blobs" in particular (the latter are believed to result from debris on the pick-off optics). We emphasize that we know the satellite ephemeri with great precision; the size and location of the eclipsed satellite will be accurately known, and therefore easily differentiated from detector effects. We need to put the target sattelite at the specific area on the detector to avoid the 'Death Star', the 'Wagon Wheel', and the spider pattern from the Jupiter. We request two orbits for the eclipse observations themselves, and another two orbits in order to re-image the same field observations once the Jupiter system has passed. This latter data will allow a measurement of any diffuse foreground galaxies which might contaminate the dark spot observation. Real Time Justification ----------------------- Since our method relies on specific astronomical events, chances for observation are limited and timing is absolutely critical; in particular, the eclipse observations must begin at the specified time. We have decided not to observe first two minutes from the beginning of the eclipse due to potential complications from latents arising from the target when it is illuminated by sunlight. Similarly, the observations must be scheduled to avoid slewing over Jupiter. We do not want to see the Jupiter even during the maneuver for pointing to prevent from the potential complications from latents. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12980( 21) - 20-Feb-2014 15:21:33 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: EUROPA-OFFSET ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE SATELLITE EUROPA ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER TYPE=POS_ANGLE, RAD=93, ANG=62, REF=NORTH ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS SEP OF EUROPA JUPITER FROM EARTH GT 5", SEP OF EUROPA CALLISTO FROM EARTH GT 30", SEP OF EUROPA GANYMEDE FROM EARTH GT 30", SEP OF EUROPA IO FROM EARTH GT 15", ECL U OF EUROPA BY JUPITER ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS 24 Vegamag/arcsec2 negative brightness at 1.4um during Target is Europa eclipsed by Jupiter. Visit will be the eclipse tracking on Jupiter and using a position angle and radius to offset to Europa. Ephemeris Center: EARTH ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 6 TARGET NAME: EUROPA-OFFSET2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE SATELLITE EUROPA ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER TYPE=POS_ANGLE, RAD=105, ANG=280, REF=NORTH ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS SEP OF EUROPA JUPITER FROM EARTH GT 10", SEP OF EUROPA CALLISTO FROM EARTH GT 30", SEP OF EUROPA GANYMEDE FROM EARTH GT 30", SEP OF EUROPA IO FROM EARTH GT 15", ECL U OF EUROPA BY JUPITER ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS 24 Vegamag/arcsec2 negative brightness at 1.4um during Target is Europa eclipsed by Jupiter. Visit will be the eclipse tracking on Jupiter and using a position angle and radius to offset to Europa. Ephemeris Center: EARTH ------------------------------------------------------------------------------------------------------------------------------------ 12980( 21) - 20-Feb-2014 15:21:33 - [ 4] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 7 TARGET NAME: EUROPA-OFFSET3 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE SATELLITE EUROPA ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER TYPE=POS_ANGLE, RAD=95, ANG=80, REF=NORTH ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS SEP OF EUROPA JUPITER FROM EARTH GT 10", SEP OF EUROPA CALLISTO FROM EARTH GT 30", SEP OF EUROPA GANYMEDE FROM EARTH GT 30", SEP OF EUROPA IO FROM EARTH GT 15", ECL U OF EUROPA BY JUPITER ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS 24 Vegamag/arcsec2 negative brightness at 1.4um during Target is Europa eclipsed by Jupiter. Visit will be the eclipse tracking on Jupiter and using a position angle and radius to offset to Europa. Ephemeris Center: EARTH ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 TARGET NAME: CALLISTO ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE SATELLITE CALLISTO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=CALLISTO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS SEP OF CALLISTO JUPITER FROM EARTH GT 30", SEP OF CALLISTO IO FROM EARTH GT 30", SEP OF CALLISTO EUROPA FROM EARTH GT 30", SEP OF CALLISTO GANYMEDE FROM EARTH GT 30", ECL U OF CALLISTO BY JUPITER ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS 24 Vegamag/arcsec2 negative brightness at 1.4um during Target is Callisto eclipsed by Jupiter the eclipse Ephemeris Center: EARTH ------------------------------------------------------------------------------------------------------------------------------------ 12980( 21) - 20-Feb-2014 15:21:33 - [ 5] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 TARGET NAME: GANYMEDE-2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE SATELLITE GANYMEDE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER TYPE=POS_ANGLE, RAD=100, ANG=55, REF=NORTH ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ECL U OF GANYMEDE-2 BY JUPITER, SEP OF GANYMEDE-2 CALLISTO FROM EARTH GT 10", SEP OF GANYMEDE-2 IO FROM EARTH GT 10", SEP OF GANYMEDE-2 EUROPA FROM EARTH GT 10" ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS 24 Vegamag/arcsec2 negative brightness at 1.4um during Target is Ganymede eclipsed by Jupiter. the eclipse Ephemeris Center: EARTH ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 5 TARGET NAME: GANYMEDE-3 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE SATELLITE GANYMEDE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 STD=JUPITER STD=GANYMEDE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS SEP OF GANYMEDE-3 JUPITER FROM EARTH GT 30", SEP OF GANYMEDE-3 CALLISTO FROM EARTH GT 30", SEP OF GANYMEDE-3 IO FROM EARTH GT 30", SEP OF GANYMEDE-3 EUROPA FROM EARTH GT 24", ECL U OF GANYMEDE-2 BY JUPITER ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS 24 Vegamag/arcsec2 negative brightness at 1.4um during Target is Ganymede eclipsed by Jupiter. the eclipse Ephemeris Center: EARTH ------------------------------------------------------------------------------------------------------------------------------------ 12980( 21) - 20-Feb-2014 15:21:33 - [ 6] Visit: 01 Visit Requirements: 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 EUROPA-OFFS WFC3/IR MULTIAC IR F139M NSAMP=13, SAMP-SEQ=SPARS25 8 DEF GS ACQ SCENARIO BASE1B3 ET CUM (2423.508 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ EUROPA-OFFSET 1 WFC3/IR MULTIAC IR F139M none none 1 none 1 N/A CUM EUROPA-OFFSET 1 WFC3/IR MULTIAC IR F139M none none 2 none 1 N/A CUM EUROPA-OFFSET 1 WFC3/IR MULTIAC IR F139M none none 3 none 1 N/A CUM EUROPA-OFFSET 1 WFC3/IR MULTIAC IR F139M none none 4 none 1 N/A CUM EUROPA-OFFSET 1 WFC3/IR MULTIAC IR F139M none none 5 none 1 N/A CUM EUROPA-OFFSET 1 WFC3/IR MULTIAC IR F139M none none 6 none 1 N/A CUM EUROPA-OFFSET 1 WFC3/IR MULTIAC IR F139M none none 7 none 1 N/A CUM EUROPA-OFFSET 1 WFC3/IR MULTIAC IR F139M none none 8 none 1 N/A CUM 12980( 21) - 20-Feb-2014 15:21:33 - [ 7] Visit: 02 Visit Requirements: 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GANYMEDE-3 WFC3/IR MULTIAC IR F160W NSAMP=14, SAMP-SEQ=SPARS25 8 DEF CUM (2623.512 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ GANYMEDE-3 1 WFC3/IR MULTIAC IR F160W none none 1 none 1 N/A CUM GANYMEDE-3 1 WFC3/IR MULTIAC IR F160W none none 2 none 1 N/A CUM GANYMEDE-3 1 WFC3/IR MULTIAC IR F160W none none 3 none 1 N/A CUM GANYMEDE-3 1 WFC3/IR MULTIAC IR F160W none none 4 none 1 N/A CUM GANYMEDE-3 1 WFC3/IR MULTIAC IR F160W none none 5 none 1 N/A CUM GANYMEDE-3 1 WFC3/IR MULTIAC IR F160W none none 6 none 1 N/A CUM GANYMEDE-3 1 WFC3/IR MULTIAC IR F160W none none 7 none 1 N/A CUM GANYMEDE-3 1 WFC3/IR MULTIAC IR F160W none none 8 none 1 N/A CUM 12980( 21) - 20-Feb-2014 15:21:33 - [ 8] Visit: 03 Visit Requirements: 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GANYMEDE-2 WFC3/IR MULTIAC IR F139M NSAMP=14, SAMP-SEQ=SPARS25 8 DEF CUM (2623.512 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ GANYMEDE-2 1 WFC3/IR MULTIAC IR F139M none none 1 none 1 N/A CUM GANYMEDE-2 1 WFC3/IR MULTIAC IR F139M none none 2 none 1 N/A CUM GANYMEDE-2 1 WFC3/IR MULTIAC IR F139M none none 3 none 1 N/A CUM GANYMEDE-2 1 WFC3/IR MULTIAC IR F139M none none 4 none 1 N/A CUM GANYMEDE-2 1 WFC3/IR MULTIAC IR F139M none none 5 none 1 N/A CUM GANYMEDE-2 1 WFC3/IR MULTIAC IR F139M none none 6 none 1 N/A CUM GANYMEDE-2 1 WFC3/IR MULTIAC IR F139M none none 7 none 1 N/A CUM GANYMEDE-2 1 WFC3/IR MULTIAC IR F139M none none 8 none 1 N/A CUM 12980( 21) - 20-Feb-2014 15:21:33 - [ 9] Visit: 04 Visit Requirements: ORIENT 255D TO 255 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 EUROPA-OFFS WFC3/IR MULTIAC IR F139M NSAMP=14, SAMP-SEQ=SPARS25 8 DEF ET2 CUM (2623.512 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ EUROPA-OFFSET2 1 WFC3/IR MULTIAC IR F139M none none 1 none 1 N/A CUM EUROPA-OFFSET2 1 WFC3/IR MULTIAC IR F139M none none 2 none 1 N/A CUM EUROPA-OFFSET2 1 WFC3/IR MULTIAC IR F139M none none 3 none 1 N/A CUM EUROPA-OFFSET2 1 WFC3/IR MULTIAC IR F139M none none 4 none 1 N/A CUM EUROPA-OFFSET2 1 WFC3/IR MULTIAC IR F139M none none 5 none 1 N/A CUM EUROPA-OFFSET2 1 WFC3/IR MULTIAC IR F139M none none 6 none 1 N/A CUM EUROPA-OFFSET2 1 WFC3/IR MULTIAC IR F139M none none 7 none 1 N/A CUM EUROPA-OFFSET2 1 WFC3/IR MULTIAC IR F139M none none 8 none 1 N/A CUM 12980( 21) - 20-Feb-2014 15:21:33 - [ 10] Visit: 05 Visit Requirements: ORIENT 117D TO 117 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 EUROPA-OFFS WFC3/IR MULTIAC IR F139M NSAMP=14, SAMP-SEQ=SPARS25 8 DEF ET3 CUM (2623.512 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ EUROPA-OFFSET3 1 WFC3/IR MULTIAC IR F139M none none 1 none 1 N/A CUM EUROPA-OFFSET3 1 WFC3/IR MULTIAC IR F139M none none 2 none 1 N/A CUM EUROPA-OFFSET3 1 WFC3/IR MULTIAC IR F139M none none 3 none 1 N/A CUM EUROPA-OFFSET3 1 WFC3/IR MULTIAC IR F139M none none 4 none 1 N/A CUM EUROPA-OFFSET3 1 WFC3/IR MULTIAC IR F139M none none 5 none 1 N/A CUM EUROPA-OFFSET3 1 WFC3/IR MULTIAC IR F139M none none 6 none 1 N/A CUM EUROPA-OFFSET3 1 WFC3/IR MULTIAC IR F139M none none 7 none 1 N/A CUM EUROPA-OFFSET3 1 WFC3/IR MULTIAC IR F139M none none 8 none 1 N/A CUM 12980( 21) - 20-Feb-2014 15:21:33 - [ 11] Summary Form for Proposal 12980 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=13, NSAMP=14, SAMP-SEQ=SPARS25 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1B3, ORIENT 117D TO 117 D, ORIENT 255D TO 255 D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F139M, F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names EUROPA-OFFSET, EUROPA-OFFSET2, EUROPA-OFFSET3, GANYMEDE-2, GANYMEDE-3 ------------------------------------------------------------------------------------------------------------------------------------