5968( 54) - 11/10/95 18:54 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5968 Version: 54 Check-in Date: ********** 1.Proposal Title: Extragalactic Background Light ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Galaxies & Clusters GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Wendy Freedman Observatories of the Carnegie Institution of Washington CoI: Barry F. Madore NASA/IPAC Extragalactic Database N CoI: Rebecca Bernstein California Institute of Technology Y ------------------------------------------------------------------------------------ 6. Abstract The integrated optical flux from the diffuse extragalactic background light (EBL) is a unique cosmological signature of the Universe. It is a volume integral of energy that has been continuously generated from the first epoch of star formation to the present day. As such it is a fundamental physical quantity, unique to this Universe and profound in its role in ultimately constraining galaxy evolution, star formation and chemical enrichment models of the Universe. The numerical value of this quantity is still unknown; however, HST is now capable of measuring it. Ground-based attempts to measure the EBL have been dominated by systematics and frustrated by the Earth's atmosphere, by opacity in the UV and by intense line emission (airglow) in the optical and near infrared. With HST we can directly access the ultraviolet and near-infrared portions of the spectrum for the first time, as well as work at optical wavelengths where the foreground contamination is reduced by as much as an order of magnitude. Furthermore, the IRAS mission has allowed us to select low 100Mum (dust- free) high-latitude windows out of the Galactic plane. Given these ultra-dark, transparent lines of sight, combined with the broad range of WFPC2 sensitivity, we are confident that a firm measurement of the integrated light and broadband spectrum of the EBL is now feasible. HST is uniquely poised to undertake this long overdue cosmological measurement. ------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 2] Observations Description ------------------------ To measure the Extragalactic Background Light (EBL) a careful subtraction of extraneous (but dominant) additional sources of light must be made. We discuss below the choice of the field, the choice of wavelengths, and the need for multiple observations at various points in the Earth's orbit. Major sources of contamination and how HST will be configured to deal with them are considered in detail. Over the past year we have consulted with Kinney, Petro, Reppert, Bely and Hasan at STScI and with Gallagher and Trauger (who are members of the WFPC2 IDT) concerning how to best design this experiment. 0.2cm centerline (i) Wavelength Selection We propose to image a single field at high-Galactic-latitude, chosen to be located at a minimum in the IRAS 100Mum Galactic cirrus maps. Three widely separated wavelengths have been selected in order both to maximize the capabilities of HST and to provide a unique complement to our extensive groundbased effort. The UV (F336W) contribution to the EBL is a virtually unexplored part of the spectrum, and is totally inaccessible from the ground. This shorter wavelength samples a much narrower redshift range than the two longer- wavelength filters (each being limited by the redshifted 912Angstrom Lyman limit), but given the unanticipated and impressive divergence of galaxy counts in the blue as opposed to the near infrared we should not be surprised to find equally dramatic differences in the integrated light components between the three wavelengths to be studied here. The optical (F555W) filter provides us with a direct tie-in to our deep ground-based effort (being undertaken at the duPont 2.5m at Las Campanas, Chile). Finally, the far red (F814W) filter gives us access to a long-wavelength (and high redshift) region that is also blocked from the ground, this time by intense and highly variable terrestrial-airglow line emission. 0.1cm centerline (ii) Zodiacal Light Outside of the Earth's atmosphere the main source of diffuse contamination is zodiacal light. At 3000Angstrom the zodiacal light contribution is a factor of 18* smaller than at 5000Angstrom; at 2500Angstrom it is smaller by a factor of 150*. In either case, even after convolving in the reduced filter bandwidth, UV transmission, and lower chip sensitivity, the resulting signal-to- zodiacal-light ratio in the UV is still a factor of 3-5* larger than the optical ratio. We consider this wavelength range to be an exciting frontier that only HST can explore. In order to avoid Galactic cirrus contamination (reflection, emission and/or extinction) our choice of an EBL field was severely constrained to regions of high Galactic latitude and minima in the 100Mum maps. Fortuitously our field still falls sufficiently above the ecliptic plane that we are within 0.6 mag of the ecliptic- pole zodiacal- light minimum value. At all of the wavelengths of interest here the zodiacal light has very well determined spectral properties, as well as a spatial distribution that is both stable and well understood. It is known, for instance, that the solar spectrum is reproduced in zodiacal light with great fidelity, both in the shape of its continuum and in the absolute depth of the individual lines: see D. Beggs, et al. 1964, MNRAS, 127, 329; and a review by A.W. Peterson 1967, in NASA SP-150, ed. J.L. Weinberg, p. 23. Moreover, the geometry of the dust layer giving rise to the backscattered zodiacal light is such that we can predict the percentage variation in the zodiacal contribution to our fields depending on the time of year (place in the orbit); and, having directly measured that fluctuation we can then scale to the total zodiacal contribution. The independent acquisition of our field at two widely separated points in the Earth's orbit will allow us to precisely measure the zodiacal contribution. Moreover, the accurately known nature of the zodiacal ( i.e., solar) spectrum additionally gives us a multi-wavelength consistency check on our solution. 0.1cm centerline (iii) Scattered Light: (a) Small-Angle Scattering According to Hasan (1992, Instrument Science Report - OTA 06.1), point- spread-function scattering tests on HST reveal that microroughness scattering from the HST primary mirror is not a problem (even in the UV) and that the wing-intensity of the PSF falls off faster than the theoretical predictions. Our field has been deliberately chosen to be devoid of bright stars. In fact the HST field has no star brighter than 16 mag on any of the four chips, and there is no star brighter than 12 mag within 10 arcmin of the field center; the nearest SAO star is nearly 1/4 degree away. It is worth noting that integrated over the three WFPC2 chips we are looking for a signal from the EBL that is equivalent to measuring a 16 mag star. All stars brighter than 28 mag will be readily identified on the composite frames (see Table 2.2, WFPC2 Instrument Handbook, V2.0, 1994) using DAOPHOT, and simply excised out to a radius of two arcsec. (Beyond this radius the surface brightness of the residual psf will have fallen to less than one part in 10^4 of the central surface brightness.) Residual halo contributions will be calculated and subtracted uniformly from the integral flux over the remainder of the chip. The two epochs requested in this proposal provide us with the added advantage of rotation of the spacecraft and its field of view that will modulate any unanticipated alignment of an off-axis star reflection that could scatter light onto the chip. Our ground-based experience shows that dithering the telescope slightly between exposures within the individual epochs also allows us to identify and correct for scattered light. By observing at two epochs and dithering between orbits, we are confident that we can identify scattered light if present, and then correct for it. centerline (iii) Scattered Light: (b) Large-Angle Scattering Given the aperture door configuration and the internal rib structure of the telescope, HST is extremely well baffled against primary sources of off-axis scattered light. Nevertheless, we still must avoid broadly scattered light from the limb of the Earth (and the Moon). Following advice on wide- angle scattering contained in STScI Technical Memos RSB- 8502/03 (Bely 1985) we are intent on keeping the exposures confined to an angular separation in excess of 40degreespoint 0 between the telescope axis and the Earth's (Moon's) illuminated limb. This constraint is distinct from `a dark- time' request. 0.1cm centerline (iv) Cosmic Rays Cosmic-ray (CR) subtraction is critical. Accordingly we are preparing to remove their contribution in at least two independent and complementary ways. First, we will explicitly cosmic- ray (CR) split the observations in each orbit into 3*1000 sec exposures. Second, the two epochs, separated by several months, will provide an additional set of implicitly CR split observations. And third, following up a suggestion by John Trauger (WFPC2 IDT) we will use the pyramid- shadowed areas found on the inner two edges along each of the CCD chips to monitor both the cosmic-ray rate and the dark counts simultaneously with the main illuminated exposure. Windhorst et al. (1994, PASP, 106, 798) have discussed aspects of the first two methods in some detail and conclude (for WF/PC 1) that there is an observed low-energy cut-off in the cosmic-ray counts detected by HST and that they did successfully measured the zodiacal light contribution to their MDS exposures. We see their very early success as a further indication that now with the refurbished instrument we can succeed in this experiment. 0.3cm 0.1cm centerline (v) Dark Counts and Hot Pixels While the WFPC2 is now operating at a lower temperature than originally planned, dark current electrons and self-illuminating (hot) pixels still need to be accounted for and subtracted in our experiment. Contemporary dark frames will be used to produce hot pixel maps and those points will then be deleted from further consideration. These same dark frames will be used to remove the dark level from each of the exposures. A single set of CR-split dark frames of duration equal to a main on-target exposure is to be obtained once during each of the two independent visits to the target in order to determine unambiguously the instantaneous dark level and the contemporary cosmic ray rate, for subsequent subtraction. As mentioned in Section (iv) above, the pyramid-shadowed regions of the WFPC2 will act as additional checks on the dark level. Real Time Justification ----------------------- (1) DARKTIME -- The primary advantage of HST in this sensitive background measurement program is access to a maximally dark sky. It is therefore a matter of some importance that this be ensured in advance to the greatest extent possible. Therefore, we are requesting that the exposures be sequenced such that at least two of the CR-split exposures be confined to the limited (53 min. at this declination) darktime period, and that the other exposures explicitly flank (but not impact) that pristine time. (2) DARK FRAMES -- Non- spatially-coincident cosmic rays can be found from CR-split frame differencing techniques, but at some point dark count events and low-energy cosmic rays become indistinguishable. We need to know the DC (bias + dark + residual low-energy cosmic ray contribution) level of the `instrumental background' at the time of our exposures. We hope to co-ordinate with STSCI the timing of our observations to be as closely associated as possible with both the decontamination (chip heating) events and their routine dark count monitoring program so that we can maximally benefit from the regular calibration process. In an instance where such co-ordination cannot be arranged we propose to use part of the non-dark time in the orbit to monitor dark/cr/bias levels ourselves. We are proposing to make all of our exposures the same length (independent of filter) in order to minimize the variables encountered in the scaling and differencing techniques needed for `instrumental background' removal, and to maximize the utility of any single set of darks taken in the course of the main program. (3) FOS PARALLEL MODE -- Without any special requirements on target acquisition etc., we believe that our program would be significantly enhanced by having the FOS in parallel operation during the entire darktime (53 min) main WFPC exposure period. With FOS positioned at a blank portion of the sky adjacent to the WFPC2 FOV (using the full collecting area of the 3.7 * 3.7 arcsec science aperture) we will be able to directly measure the zodiacal light contribution to our broadband images. This can be accomplished by using the equivalent width of the Mg II triplet at 5186Angstrom (which is well matched to the G570H grating and the red digicon detector) and scaling it to the corresponding broadband continuum level. While we are both proposing a geometrical solution to determining the zodiacal light contamination (see above and below) as well as a groundbased approach, it is clear that zodiacal light is the largest single contaminant in this experiment from space, and it deserves redundant attention to its removal. Discussions with A. Kinney and A. Koratkar (STScI) indicate that FOS can indeed now be used in this mode without adding any additional orbits so long as we instruct FOS to complete its exposure and read-out before the WFPC2 read-out is begun. (4) DISTRIBUTED OBSERVATIONS -- While zodiacal light is the main contaminant in this experiment, the spatial distribution and the spectral characterization of zodiacal light are extremely well understood. And we can use this understanding to great advantage in removing it from our integrations. Because the Earth is not centrally located with respect to the zodiacal dust distribution (which is symmetric about the Sun) we see through this dust torus differently from various points in the Earth's orbit. By separating our suite of observations into two distinct periods we can modulate the zodiacal contribution in a way that is predictable in amplitude. Furthermore, having measured the amplitude we can use it to scale to the total line of sight contribution, thereby effectively removing the single largest contaminant in a single step. Because this is such an important step we have built in cross checks which come from the broadband spectrum of the geometrically removed portion itself (i.e., the UV/visual/near-IR components identified by this step must be Solar in color), from the simultaneous FOS observations of the optical spectrum of the zodiacal light directly (see above), and from the co-ordinated groundbased effort (see below). We have already begun and will continue to monitor this (and several other nearby EBL fields) at Las Campanas using a 2048*2048 thinned CCD on the 2.5m duPont 100-inch. We are using a combination of broadband and narrowband filters chosen to enable us to scale out the zodiacal contribution using the known solar equivalent width of the Mg II absorption features at 5800Angstrom. At least one of the up-coming ground-based observing sessions will be scheduled by the PI's home institution to coincide with one of the HST observations. These observations include simultaneous spectroscopic and direct imaging of the EBL fields followed by a co-ordinated use of the Swope 1m wide-field imaging CCD in concert with the duPont 2.5m. In so doing we have been monitoring the airglow and simultaneously measuring the zodiacal spectrum so thatt heir individual contributions to the total contamination can be identified and scaled out. Since the zodiacal light contribution is a stable function of ecliptic latitude and apparent longitude, a measurement of the zodiacal light contribution made from the ground will also be directly applicable, and will provide a consistency check on the solutions for the zodiacal light contamination of the HST observations. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 EBL1 UNIDENTIFIED, BLANK RA = 3H 00M 21.91S +/- 0.07S , J2000 V = 15 FIELD DEC = -20D 10' 44.7" +/- 1" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 0 0 0 2 ZOD1 UNIDENTIFIED, BLANK RA = 2H 59M 47.42S , DEC = -20D J2000 V = 22 FIELD 12' 0.0" , REGION , R=5' Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 0 0 0 3 EBL2 UNIDENTIFIED,BLANK RA = 3H 00M 20.4S +/- 0.07S , J2000 V = 15 FIELD DEC = -20D 10' 45.3" +/- 1" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 0 0 0 4 ZOD2 UNIDENTIFIED,BLANK RA = 3H 00M 15.02S , DEC = -20D J2000 V = 22 FIELD 02' 38.6" , REGION , R=5' Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) J2000 0 0 0 5968( 54) - 11/10/95 18:54 - [ 5] Visit: 01 Visit Requirements: BETWEEN 27-OCT-1995:12:00:00 AND 30-OCT-1995:15:00:00 ORIENT 314.0D TO 316.0D PCS MODE F On Hold Comments: Additional Comments: Link to DECON. For maximum sensitivity in the near-UV, our program would benefit greatly from decontamination close to and preceding EACH visit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 101 EBL1 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 1800S SHADOW POS TARG +0.0 , +0.0 FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 102 ZOD1 FOS/RD ACCUM 1.0- G570H STEP-PATT = 1 1300S PAR WITH 101 PAIR-A SINGLE Comments: This exposure should be simultanious with exp. 101 and last as long as possible w/o interfering with Exp 101. ------------------------------------------------------------------------------------------------------------------------------------ 103 EBL1 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 100S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 104 BIAS WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 10 0S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. If data storage is a problem, reduce the # of bias frames. ------------------------------------------------------------------------------------------------------------------------------------ 106 EBL1 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 1900S SHADOW POS TARG +1.1 , +0.0 FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 107 ZOD1 FOS/RD ACCUM 1.0- G570H STEP-PATT = 1 1500S PAR WITH 106 PAIR-A SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 108 EBL1 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 160S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 109 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 111 EBL1 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 1900S SHADOW POS TARG +0.0 , -1.0 FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 112 ZOD1 FOS/RD ACCUM 1.0- G570H STEP-PATT = 1 1500S PAR WITH 111 PAIR-A SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 113 EBL1 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 160S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 114 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 116 EBL1 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 1900S SHADOW POS TARG +2.2 , -2.2 FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 117 ZOD1 FOS/RD ACCUM 1.0- G570H STEP-PATT = 1 1500S PAR WITH 116 PAIR-A SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 118 EBL1 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 160S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 119 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 121 EBL1 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 1900S SHADOW POS TARG +2.2 , -1.1 FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 122 ZOD1 FOS/RD ACCUM 1.0- G570H STEP-PATT = 1 1500S PAR WITH 121 PAIR-A SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 123 EBL1 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 160S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 124 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 126 EBL1 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 1900S SHADOW SEQ 126,128 NON-INT POS TARG +1.1 , FIX ATD-GAIN = 7 -2.2 ------------------------------------------------------------------------------------------------------------------------------------ 127 ZOD1 FOS/RD ACCUM 1.0- G570H STEP-PATT = 1 1500S PAR WITH 126 PAIR-A SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 128 EBL1 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 160S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 129 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 ------------------------------------------------------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 7] Visit: 02 Visit Requirements: BETWEEN 25-NOV-1995:12:00:00 AND 28-NOV-1995:15:00:00 ORIENT 90.0D TO 90.0D FROM 1 PCS MODE F On Hold Comments: Additional Comments: Link to DECON. For maximum sensitivity in the near-UV, our program would benefit from decontamination close to and preceding EACH visit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 200 EBL2 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 400S POS TARG -1.1 , +1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 201 EBL2 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 1800S SHADOW SEQ 200-201 NON-INT POS TARG +0.0 , FIX ATD-GAIN = 7 +0.0 ------------------------------------------------------------------------------------------------------------------------------------ 202 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1300S PAR WITH 201 SINGLE Comments: This exposure should be simultanious with exposure 201. and last as long as possible w/o interfering with Exp 201. ------------------------------------------------------------------------------------------------------------------------------------ 204 BIAS WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 10 0S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. If data storage is a problem, reduce the # of bias frames. ------------------------------------------------------------------------------------------------------------------------------------ 205 EBL2 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 400S POS TARG -1.1 , +1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 206 EBL2 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 1800S SHADOW SEQ 205-206 NON-INT POS TARG -1.1 , FIX ATD-GAIN = 7 +0.0 ------------------------------------------------------------------------------------------------------------------------------------ 207 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 206 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 209 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 210 EBL2 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 400S POS TARG -1.1 , +1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 211 EBL2 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 1800S SHADOW SEQ 210-211 NON-INT POS TARG +0.0 , FIX ATD-GAIN = 7 +1.1 ------------------------------------------------------------------------------------------------------------------------------------ 212 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 211 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 8] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 214 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 215 EBL2 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 400S POS TARG -1.1 , +1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 216 EBL2 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 1800S SHADOW SEQ 215-216 NON-INT POS TARG -2.2 , FIX ATD-GAIN = 7 +2.2 ------------------------------------------------------------------------------------------------------------------------------------ 217 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 216 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 219 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 220 EBL2 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 400S POS TARG -1.1 , +1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 221 EBL2 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 1800S SHADOW SEQ 220-221 NON-INT POS TARG -2.2 , FIX ATD-GAIN = 7 +1.1 ------------------------------------------------------------------------------------------------------------------------------------ 222 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 221 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 224 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 225 EBL2 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 400S POS TARG -1.1 , +1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 226 EBL2 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 1800S SHADOW SEQ 225-226 NON-INT POS TARG -1.1 , FIX ATD-GAIN = 7 +2.2 ------------------------------------------------------------------------------------------------------------------------------------ 227 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 226 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 229 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 9] Visit: 03 Visit Requirements: BETWEEN 18-DEC-1995:12:00:00 AND 21-DEC-1995:15:00:00 SAME ORIENT AS 2 PCS MODE F On Hold Comments: Additional Comments: Link to DECON. For maximum sensitivity in the near-UV, our program would benefit from decontamination close to and preceding EACH visit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 300 EBL2 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 200S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 301 EBL2 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 1800S SHADOW SEQ 300-301 NON-INT POS TARG +0.0 , FIX ATD-GAIN = 7 +0.0 ------------------------------------------------------------------------------------------------------------------------------------ 302 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1300S PAR WITH 301 SINGLE Comments: This exposure should be simultanious with exposure 101. and last as long as possible w/o interfering with Exp 101. ------------------------------------------------------------------------------------------------------------------------------------ 304 BIAS WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 10 0S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. If data storage is a problem, reduce the # of bias frames. ------------------------------------------------------------------------------------------------------------------------------------ 305 EBL2 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 200S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 306 EBL2 WFPC2 IMAGE WFALL- F555W CR-SPLIT = NO 1 1800S SHADOW SEQ 305-306 NON-INT POS TARG +1.1 , FIX ATD-GAIN = 7 +0.0 ------------------------------------------------------------------------------------------------------------------------------------ 307 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 306 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 309 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 310 EBL2 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 200S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 311 EBL2 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 1800S SHADOW SEQ 310-311 NON-INT POS TARG +0.0 , FIX ATD-GAIN = 7 -1.1 ------------------------------------------------------------------------------------------------------------------------------------ 312 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 311 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 10] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 314 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 315 EBL2 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 200S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 316 EBL2 WFPC2 IMAGE WFALL- F814W CR-SPLIT = NO 1 1800S SHADOW SEQ 315-316 NON-INT POS TARG +2.2 , FIX ATD-GAIN = 7 -2.2 ------------------------------------------------------------------------------------------------------------------------------------ 317 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 316 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 319 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 320 EBL2 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 200S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 321 EBL2 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 1800S SHADOW SEQ 320-321 NON-INT POS TARG +2.2 , FIX ATD-GAIN = 7 -1.1 ------------------------------------------------------------------------------------------------------------------------------------ 322 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 321 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 324 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 325 EBL2 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 200S POS TARG +1.1 , -1.1 LOW-SKY FIX ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ 326 EBL2 WFPC2 IMAGE WFALL- F300W CR-SPLIT = NO 1 1800S SHADOW SEQ 325-326 NON-INT POS TARG +1.1 , FIX ATD-GAIN = 7 -2.2 ------------------------------------------------------------------------------------------------------------------------------------ 327 ZOD2 FOS/RD ACCUM 4.3 G650L STEP-PATT = 1 1460S PAR WITH 326 SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 329 DARK WFPC2 IMAGE WFALL DEF CR-SPLIT=NO, 1 1700S CLOCKS=NO, ATD- GAIN=7 Comments: This should be done while target is occulted. ------------------------------------------------------------------------------------------------------------------------------------ 5968( 54) - 11/10/95 18:54 - [ 11] Summary Form for Proposal 5968 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT = NO ATD-GAIN = 7 STEP-PATT = SINGLE ATD-GAIN=7 CLOCKS=NO CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Galaxies & Clusters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 27-OCT-1995 12 00 00 AND 30-OCT-1995 15 00 00 ORIENT 314.0D TO 316.0D PCS MODE F SHADOW POS TARG +0.0 , +0.0 PAR WITH 101 POS TARG +1.1 , -1.1 LOW-SKY SHADOW POS TARG +1.1 , +0.0 PAR WITH 106 SHADOW POS TARG +0.0 , -1.0 PAR WITH 111 SHADOW POS TARG +2.2 , -2.2 PAR WITH 116 SHADOW POS TARG +2.2 , -1.1 PAR WITH 121 SHADOW SEQ 126,128 NON-INT POS TARG +1.1 , -2.2 PAR WITH 126 BETWEEN 25-NOV-1995 12 00 00 AND 28-NOV-1995 15 00 00 ORIENT 90.0D TO 90.0D FROM 1 PCS MODE F POS TARG -1.1 , +1.1 LOW-SKY SHADOW SEQ 200-201 NON-INT POS TARG +0.0 , +0.0 PAR WITH 201 SHADOW SEQ 205-206 NON-INT POS TARG -1.1 , +0.0 PAR WITH 206 SHADOW SEQ 210-211 NON-INT POS TARG +0.0 , +1.1 PAR WITH 211 SHADOW SEQ 215-216 NON-INT POS TARG -2.2 , +2.2 PAR WITH 216 SHADOW SEQ 220-221 NON-INT POS TARG -2.2 , +1.1 PAR WITH 221 SHADOW SEQ 225-226 NON-INT POS TARG -1.1 , +2.2 PAR WITH 226 BETWEEN 18-DEC-1995 12 00 00 AND 21-DEC-1995 15 00 00 SAME ORIENT AS 2 PCS MODE F SHADOW SEQ 300-301 NON-INT POS TARG +0.0 , +0.0 PAR WITH 301 SHADOW SEQ 305-306 NON-INT POS TARG +1.1 , +0.0 PAR WITH 306 SHADOW SEQ 310-311 NON-INT POS TARG +0.0 , -1.1 PAR WITH 311 SHADOW SEQ 315-316 NON-INT POS TARG +2.2 , -2.2 PAR WITH 316 SHADOW SEQ 320-321 NON-INT POS TARG +2.2 , -1.1 PAR WITH 321 SHADOW SEQ 325-326 NON-INT POS TARG +1.1 , -2.2 PAR WITH 326 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W G570H DEF F814W F300W G650L ------------------------------------------------------------------------------------------------------------------------------------ Target Names EBL1 ZOD1 BIAS DARK EBL2 ZOD2 ------------------------------------------------------------------------------------------------------------------------------------