7852( 10) - 06/15/98 16:16 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7852 Version: 10 Check-in Date: 15-Jun-1998 16:13:23 1.Proposal Title: Weighing the Stellar Halo of NGC 5907 with NICMOS ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: STEPHEN ZEPF Yale University CoI: Mike Liu University of California N CoI: Dr. Penny Sackett University of Groningen N ------------------------------------------------------------------------------------ 5. Abstract We propose to obtain NICMOS H-band images of NGC 5907 in order to determine the composition of its stellar halo. Previous ground-based observations have discovered that NGC 5907 has a stellar halo with a radial profile that roughly traces the isothermal profile required to reproduce the rotation curve. However, these studies have been unable to determine if the light is primarily composed of giants, which would result from a typical stellar initial mass function, or dwarfs, which would be required to give the high mass-to-light ratio necessary to make the population dynamically significant. Our proposed NICMOS images will cleanly distinguish between these possibilities. Specifically, we will readily detect many individual bright stars if giants contribute significantly to the halo light, whereas we will not resolve the population if it is dominated by dwarfs. The two hypotheses can also be clearly differentiated on the basis of the observed surface brightness fluctuations, providing an independent check on the results. The proposed observations offer a clean test of the stellar composition of the halo of NGC 5907 and therefore of the speculative possibility that the faint r^-2 stellar halo observed in this galaxy is the first demonstrated example of a baryonic dark matter halo. ------------------------------------------------------------------------------------ 7852( 10) - 06/15/98 16:16 - [ 2] Observations Description ------------------------ We propose to determine whether the halo light of NGC 5907 is dominated by dwarfs or giants by obtaining deep NICMOS images of a field in the halo of this galaxy. We will use the F160W (H-band) filter with NIC2 in primary mode, and the F110W (J- band) filter with NIC1 in parallel mode. Because of the low background and high spatial resolution of NICMOS+HST it is feasible to detect the brightest few magnitudes of the luminosity function of stellar population like that in the bulge of the Galaxy and M31. As shown in Figure 2, integration of 12 orbits in H will reliably detect more than several hundred stars at a surface brightness of H = 23.5 mag/arcsec^2 (corresponding to a radius of about 60''), if the luminosity function is like that of the Galactic bulge. At lower metallicities, which may be more appropriate for the halo of NGC 5907, the stars will be fainter by up to 1.5 magnitudes in H. Thus, in this case, it is necessary to obtain reliable photometry on stars in the range 24 < H < 25. As shown in the simulations, and verified by use of the Exposure Time Calculator, this can be achieved in 12 orbits. The lower panel in Figure 2 dramatically demonstrates that a population with a steeper IMF (more light from unevolved dwarfs) produce dramatically fewer bright stars. Thus the proposed observations cleanly distinguish between the two possibilities. In order to constrain the metallicity and to thus tighten the limits on the dwarf/giant raatio and the IMF, we also propose to use NIC1 in parallel to obtain J-band images. By comparing the stellar lumiunosity function in J and H, we will be able to estimate the metallicity of the brightest stars. Finally, we note that to insure accurate photometry and characterization of the SBFs of the unresolved light, we will use part of one of the requested orbits to acquire psf observations of our own. Although previous experience with the WFPC2 psf indicates that it fairly stable over time, obtaining a psf observation before or after our visit to the galaxy is a prudent step. The exposure time required is very short (~ 10s), but the slewing and re- acquisition time are likely to take approximately 1/2 of an orbit. Real Time Justification ----------------------- None. We are building from extensive pre-existing ground-based observations of this object. Only NICMOS can clearly detect luminous giants that may comprise much of the halo of NGC 5907. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7852( 10) - 06/15/98 16:16 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5907-HALO galaxy, spiral RA=15H 16M 01.54S +/- 0.1S, 2000 Z=0.002 SURF(H) = 23.5 DEC=56D 20' 31.7" +/- 1"PLATE- ID=07PP 7852( 10) - 06/15/98 16:16 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0 S SEQ 1-2 NON-INT Comments: Exposure 1 designed to reduce persistence effects. RPS2 currently complains about the dark target and the exposure time. The Dark has been approved by the program scientist, and the exposure time is a legal one. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF PAR 3 WITH 2 O CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF PAR 5 WITH 4 POS TARG 1.1 O CUM , +0.0 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0 S SEQ 6-7 NON-INT Comments: Exposure 6 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the second orbit. ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +2.2, +0.0 PAR 8 O CUM WITH 7 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +3.3, +0.0 PAR O CUM 10 WITH 9 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 11 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0.0 S SEQ 11-12 NON-INT Comments: Exposure 11 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the third orbit. ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +4.4, +0.0 PAR O CUM 13 WITH 12 ------------------------------------------------------------------------------------------------------------------------------------ 7852( 10) - 06/15/98 16:16 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +4.4, +1.1 PAR O CUM 15 WITH 14 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 16 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0.0 S SEQ 16-17 NON-INT Comments: Exposure 16 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the fourth orbit. ------------------------------------------------------------------------------------------------------------------------------------ 17 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF PAR 18 WITH 17 POS TARG O CUM +3.3, +1.1 ------------------------------------------------------------------------------------------------------------------------------------ 18 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 19 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +2.2, +1.1 PAR O CUM 20 WITH 19 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 21 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0.0 S SEQ 21-22 NON-INT Comments: Exposure 21 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the fifth orbit. ------------------------------------------------------------------------------------------------------------------------------------ 22 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +1.1,+1.1 PAR 23 O CUM WITH 22 ------------------------------------------------------------------------------------------------------------------------------------ 23 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 24 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +0.0, +1.1 PAR O CUM 25 WITH 24 ------------------------------------------------------------------------------------------------------------------------------------ 25 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 7852( 10) - 06/15/98 16:16 - [ 6] Visit: 02 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0 S SEQ 1-2 NON-INT Comments: Exposure 1 designed to reduce persistence effects. RPS2 currently complains about the dark target and the exposure time. The Dark has been approved by the program scientist, and the exposure time is a legal on. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +0.0,+2.2 PAR 3 O CUM WITH 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF PAR 5 WITH 4 POS TARG O CUM +1.1, +2.20 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0 S SEQ 6-7 NON-INT Comments: Exposure 6 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the second orbit. ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +2.2, +2.20 PAR O CUM 8 WITH 7 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +3.3, +2.2 PAR O CUM 10 WITH 9 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 11 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0 S SEQ 11-12 NON-INT Comments: Exposure 11 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the fifth orbit. ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +4.4, +2.2 PAR O CUM 13 WITH 12 ------------------------------------------------------------------------------------------------------------------------------------ 7852( 10) - 06/15/98 16:16 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +4.4, +3.3 PAR O CUM 15 WITH 14 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 16 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0.0 S SEQ 16-17 NON-INT Comments: Exposure 16 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the fourth orbit. ------------------------------------------------------------------------------------------------------------------------------------ 17 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF PAR 18 WITH 17 POS TARG O CUM +3.3,+3.3 ------------------------------------------------------------------------------------------------------------------------------------ 18 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 19 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +2.2, +3.3 PAR O CUM 20 WITH 19 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 7852( 10) - 06/15/98 16:16 - [ 8] Visit: 03 Visit Priority: Visit Requirements: SAME ORIENTation AS 2 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0 S SEQ 1-2 NON-INT Comments: Exposure 1 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the first orbit of this visit. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +1.1, +3.3 PAR 3 O CUM WITH 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +0.0, +3.3 PAR 5 O CUM WITH 4 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0 S SEQ 6-7 NON-INT Comments: Exposure 6 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the sixth orbit. ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +0.0, +4.4 PAR 8 O CUM WITH 7 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +1.1,+4.4 PAR 10 O CUM WITH 9 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 11 DARK NIC2 ACCUM NIC2 F160W 1.6 NREAD=25 1 0 S SEQ 11-12 NON-INT Comments: Exposure 11 designed to reduce persistence effects (see exposure 1 for additional comments. It would ideally occur at the begining of the third orbit. ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +2.2, +4.4 PAR O CUM 13 WITH 12 ------------------------------------------------------------------------------------------------------------------------------------ 7852( 10) - 06/15/98 16:16 - [ 9] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC5907-HAL NIC2 MULTIAC NIC2 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF POS TARG +3.3, +4.4 PAR O CUM 15 WITH 14 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC5907-HAL NIC1 MULTIAC NIC1 F160W 1.6 SAMP-SEQ=SPARS64,NSAMP=25 1 DEF O CUM ------------------------------------------------------------------------------------------------------------------------------------ 7852( 10) - 06/15/98 16:16 - [ 10] Summary Form for Proposal 7852 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures NIC2 NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC2 NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NREAD=25 NSAMP=25 SAMP-SEQ=SPARS64 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 1-2 NON-INT PAR 3 WITH 2 PAR 5 WITH 4 POS TARG 1.1, +0.0 SEQ 6-7 NON-INT POS TARG +2.2, +0.0 PAR 8 WITH 7 POS TARG +3.3, +0.0 PAR 10 WITH 9 SEQ 11-12 NON-INT POS TARG +4.4, +0.0 PAR 13 WITH 12 POS TARG +4.4, +1.1 PAR 15 WITH 14 SEQ 16-17 NON-INT PAR 18 WITH 17 POS TARG +3.3, +1.1 POS TARG +2.2, +1.1 PAR 20 WITH 19 SEQ 21-22 NON-INT POS TARG +1.1,+1.1 PAR 23 WITH 22 POS TARG +0.0, +1.1 PAR 25 WITH 24 POS TARG +0.0,+2.2 PAR 3 WITH 2 PAR 5 WITH 4 POS TARG +1.1, +2.20 POS TARG +2.2, +2.20 PAR 8 WITH 7 POS TARG +3.3, +2.2 PAR 10 WITH 9 POS TARG +4.4, +2.2 PAR 13 WITH 12 POS TARG +4.4, +3.3 PAR 15 WITH 14 PAR 18 WITH 17 POS TARG +3.3,+3.3 POS TARG +2.2, +3.3 PAR 20 WITH 19 SAME ORIENTation AS 2 POS TARG +1.1, +3.3 PAR 3 WITH 2 POS TARG +0.0, +3.3 PAR 5 WITH 4 POS TARG +0.0, +4.4 PAR 8 WITH 7 POS TARG +1.1,+4.4 PAR 10 WITH 9 POS TARG +2.2, +4.4 PAR 13 WITH 12 POS TARG +3.3, +4.4 PAR 15 WITH 14 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names DARK NGC5907-HALO ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1.6 ------------------------------------------------------------------------------------------------------------------------------------