11098( 6) - 02/28/07 19:03 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11098 Version: 6 Check-in Time: 01-Mar-2007 00:02:34 STScI Edit Number: 0 Title Pinning down the redshift of the J-band dropout JD0910+46 ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO/DD 15 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Andrew J. Levan The University of Warwick CoI: Prof. Nial R. Tanvir University of Leicester N CoI: Dr. Andrew S. Fruchter Space Telescope Science Institute N CoI: Dr. James Rhoads Arizona State University N CoI: Dr. Malcolm Bremer University of Bristol N CoI: Dr. Robert S. Priddey University of Hertfordshire N CoI: Dr. Pall Jakobsson University of Hertfordshire N CoI: Dr. Evert Rol University of Leicester N CoI: Dr. Jens Hjorth University of Copenhagen, Niels Bohr N Institute CoI: Dr. Melissa C. Nysewander Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract The earliest galaxies in the Universe should have formed at very high redshifts, based both on models of hierarchical structure formation, and on observations of the microwave background polarization by WMAP that require significant ionization of the intergalactic medium before z=10. However, direct observation of sources at z>7 remains highly challenging due to their scarcity and faintness. We recently identified a spatially extended J-band dropout, JD0910+46, that is a promising candidate for a z>10 galaxy. Its spectral energy distribution is more extreme than any previously reported: It is undetected in our 2-orbit J-band observation, with a very red J-H color, yet is bluer in H-K than plausible lower redshift (z~3) model SEDs. These colors are, however, natural for a very high redshift star-burst galaxy in which the Lyman-alpha break has moved mostly or entirely through the F110W band. Here we propose deeper F110W and F187W observations to better map the spectral energy distribution of JD910+46, these have the potential to convincingly reject all low redshift solutions for the origin of the observed colours. We believe the importance of such a discovery adds urgency to the followup, and motivates this DD request. Even in the event that JD0910+46 lies at lower redshift understanding the nature of the object will be of great importance since it may lie in a significant overdensity of galaxies at z~4, and will be an important tool for identifying possible interlopers in samples of ultra high-z galaxies. ------------------------------------------------------------------------------------ 11098( 6) - 02/28/07 19:03 - [ 2] Observations Description ------------------------ We wish to observe JD0910+46 using NICMOS. The purpose of these observations is to secure a deep limit (or detection) of JD0910+46 in the F110W band. We will perform a total of eight orbits over two visits with an 8 point dither pattern in each of them. This will allow us to reach 2-sigma limiting magnitudes of F110W(AB)~27.5. We will perform two, four orbit visits, with two exposures per orbit to aid the SAA correction. Each visit will perform a 8-point dither pattern to allow some reconstruction of the PSF via drizzle, while we perform a constant POSTARG offset of 4" between the first and second visit to aid the production of a "master" sky flat. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11098( 6) - 02/28/07 19:03 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 JD910+46 GALAXY, HIGH REDSHIFT RA=09H09M52.1300S +/- 0.1", J2000 V = 29.0+/-1.0 GALAXY DEC=+45D39'44.90" +/- 0.1" H(AB)=23.8 K(AB)=23.2 Reference Frame: GSC1 11098( 6) - 02/28/07 19:03 - [ 4] Visit: 01 Visit Priority: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG -1.426,-1.421 CUM ------------------------------------------------------------------------------------------------------------------------------------ 2 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG -1.426, 1.523 CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 1.528,-1.421 CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 1.528, 1.523 CUM ------------------------------------------------------------------------------------------------------------------------------------ 5 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG -1.681,-1.675 CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG -1.681, 1.675 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 1.681,-1.675 CUM ------------------------------------------------------------------------------------------------------------------------------------ 8 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 1.681, 1.675 CUM ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ JD910+46 1 NIC3 MULTIAC NIC3 F110W none none none none 1 N/A CUM JD910+46 2 NIC3 MULTIAC NIC3 F110W none none none none 1 N/A CUM JD910+46 3 NIC3 MULTIAC NIC3 F110W none none none none 2 N/A CUM JD910+46 4 NIC3 MULTIAC NIC3 F110W none none none none 2 N/A CUM JD910+46 5 NIC3 MULTIAC NIC3 F110W none none none none 3 N/A CUM 11098( 6) - 02/28/07 19:03 - [ 5] 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 | ------------------------------------------------------------------------------------------------------------------------------------ JD910+46 6 NIC3 MULTIAC NIC3 F110W none none none none 3 N/A CUM JD910+46 7 NIC3 MULTIAC NIC3 F110W none none none none 4 N/A CUM JD910+46 8 NIC3 MULTIAC NIC3 F110W none none none none 4 N/A CUM 11098( 6) - 02/28/07 19:03 - [ 6] Visit: 02 Visit Priority: 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 2.574, 2.579 CUM ------------------------------------------------------------------------------------------------------------------------------------ 2 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 2.574, 5.523 CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 5.528, 2.579 CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 5.528, 5.523 CUM ------------------------------------------------------------------------------------------------------------------------------------ 5 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 2.319, 2.325 CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 2.319, 5.675 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 5.681, 2.325 CUM ------------------------------------------------------------------------------------------------------------------------------------ 8 JD910+46 NIC3 MULTIAC NIC3 F110W NSAMP=22,SAMP-SEQ=SPARS64 1 DEF POS TARG 5.681, 5.675 CUM ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ JD910+46 1 NIC3 MULTIAC NIC3 F110W none none none none 1 N/A CUM JD910+46 2 NIC3 MULTIAC NIC3 F110W none none none none 1 N/A CUM JD910+46 3 NIC3 MULTIAC NIC3 F110W none none none none 2 N/A CUM JD910+46 4 NIC3 MULTIAC NIC3 F110W none none none none 2 N/A CUM JD910+46 5 NIC3 MULTIAC NIC3 F110W none none none none 3 N/A CUM 11098( 6) - 02/28/07 19:03 - [ 7] 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 | ------------------------------------------------------------------------------------------------------------------------------------ JD910+46 6 NIC3 MULTIAC NIC3 F110W none none none none 3 N/A CUM JD910+46 7 NIC3 MULTIAC NIC3 F110W none none none none 4 N/A CUM JD910+46 8 NIC3 MULTIAC NIC3 F110W none none none none 4 N/A CUM 11098( 6) - 02/28/07 19:03 - [ 8] Summary Form for Proposal 11098 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures NIC3 ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC3 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=22 SAMP-SEQ=SPARS64 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG -1.426,-1.421; POS TARG -1.426, 1.523; POS TARG 1.528,-1.421; POS TARG 1.528, 1.523; POS TARG -1.681,-1.675; POS TARG -1.681, 1.675; POS TARG 1.681,-1.675; POS TARG 1.681, 1.675; POS TARG 2.574, 2.579; POS TARG 2.574, 5.523; POS TARG 5.528, 2.579; POS TARG 5.528, 5.523; POS TARG 2.319, 2.325; POS TARG 2.319, 5.675; POS TARG 5.681, 2.325; POS TARG 5.681, 5.675; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W ------------------------------------------------------------------------------------------------------------------------------------ Target Names JD910+46 ------------------------------------------------------------------------------------------------------------------------------------