Proposal_Information
Title: Extragalactic Background Light
Proposal_Category: GO
Scientific_Category: Galaxies & Clusters
Cycle: 5
Investigators
PI_name: Wendy Freedman
PI_Institution: Observatories of the Carnegie Institution of
Washington
CoI_Name: Barry F. Madore
CoI_Institution: NASA/IPAC Extragalactic Database
Contact: ! Y or N (designate at most one contact)
CoI_Name: Rebecca Bernstein
CoI_Institution: California Institute of Technology
Contact: Y ! Y or N (designate at most one contact)
Abstract: ! Free format text (please update)
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.
Questions ! Free format text (please update)
Observing_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:
Fixed_Targets
Target_Number: 1
Target_Name: EBL1 ! visit 1, ORIENT 312.0D-314.0D (guidestars @ 312.7)
Alternate_Names:
Description: UNIDENTIFIED, BLANK FIELD
Position: RA = 3H 00M 21.91S +/- 0.07S , DEC = -20D 10' 44.7" +/- 1"
Equinox: J2000
RV_or_Z:
RA_PM: 0
Dec_PM: 0
Epoch: J2000
Annual_Parallax: 0
Flux: V = 15
Comments:
Target_Number: 2
Target_Name: ZOD1
Alternate_Names:
Description: UNIDENTIFIED, BLANK FIELD
Position: RA = 2H 59M 47.42S , DEC = -20D 12' 0.0" , REGION , R=5'
Equinox: J2000
RV_or_Z:
RA_PM: 0
Dec_PM: 0
Epoch: J2000
Annual_Parallax: 0
Flux: V = 22
Comments:
Target_Number: 3
Target_Name: EBL2 ! visit 2&3, ORIENT 312.0D-314.0D (guidestars @ 42.7)
Alternate_Names:
Description: UNIDENTIFIED,BLANK FIELD
Position: RA = 3H 00M 20.4S +/- 0.07S , DEC = -20D 10' 45.3" +/- 1"
Equinox: J2000
RV_or_Z:
RA_PM: 0 ! Units are seconds of time per year
Dec_PM: 0 ! Units are seconds of arc per year
Epoch: J2000
Annual_Parallax: 0
Flux: V = 15 ! Include at least V and B-V
Comments:
Target_Number: 4
Target_Name: ZOD2
Alternate_Names:
Description: UNIDENTIFIED,BLANK FIELD
Position: RA = 3H 00M 15.02S , DEC = -20D 02' 38.6" , REGION , R=5'
Equinox: J2000
RV_or_Z:
RA_PM: 0 ! Units are seconds of time per year
Dec_PM: 0 ! Units are seconds of arc per year
Epoch: J2000
Annual_Parallax: 0
Flux: V = 22 ! Include at least V and B-V
Comments:
Visits
Visit_Number: 1
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:
Visit_Comments: Link to DECON. For maximum sensitivity in the near-UV,
our program would benefit greatly from decontamination
close to and preceding EACH visit.
! -----------Orbit 1 -------------
Exposure_Number: 101
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W ! center 5407 width 1236
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
! SEQ 101,103 NON-INT
POS TARG +0.0 , +0.0
Exposure_Number: 102
Target_Name: ZOD1
Config: FOS/RD
Opmode: ACCUM
Aperture: 1.0-PAIR-A
Sp_Element: G570H ! 4571-6820 \AA
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1300S
Special_Requirements: PAR WITH 101
Comments: This exposure should be simultanious with exp. 101 and
last as long as possible w/o interfering with Exp 101.
Exposure_Number: 103
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 100S
Special_Requirements: POS TARG +1.1 , -1.1 ! 11 * 0.10" = 23.91 * 0.046"
LOW-SKY
Exposure_number: 104
Target_Name: BIAS
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:10
Time_Per_Exposure: 0S
Special_Requirements:
Comments: This should be done while target is occulted.
If data storage is a problem, reduce the # of bias frames.
! -----------Orbit 2 -------------
Exposure_Number: 106
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1900S
Special_Requirements: SHADOW
! SEQ 106,108 NON-INT
POS TARG +1.1 , +0.0
Exposure_Number: 107
Target_Name: ZOD1
Config: FOS/RD
Opmode: ACCUM
Aperture: 1.0-PAIR-A
Sp_Element: G570H ! 4571-6820
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1500S
Special_Requirements: PAR WITH 106
Comments:
Exposure_Number: 108
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 160S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 109
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 3 -------------
Exposure_Number: 111
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W ! center 7940 width 1531
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1900S
Special_Requirements: SHADOW
! SEQ 111,113 NON-INT
POS TARG +0.0 , -1.0
Exposure_Number: 112
Target_Name: ZOD1
Config: FOS/RD
Opmode: ACCUM
Aperture: 1.0-PAIR-A
Sp_Element: G570H ! 3 orbits with this grating,
Wavelength: ! 3 with the G650L grating.
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1500S
Special_Requirements: PAR WITH 111
Comments:
Exposure_Number: 113
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 160S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 114
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 4 -------------
Exposure_Number: 116
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1900S
Special_Requirements: SHADOW
! SEQ 116,118 NON-INT
POS TARG +2.2 , -2.2
Exposure_Number: 117
Target_Name: ZOD1
Config: FOS/RD
Opmode: ACCUM
Aperture: 1.0-PAIR-A
Sp_Element: G570H
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1500S
Special_Requirements: PAR WITH 116
Comments:
Exposure_Number: 118
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 160S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 119
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 5 -------------
Exposure_Number: 121
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W ! center 2911 width 745
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1900S
Special_Requirements: SHADOW
! SEQ 121,123 NON-INT
POS TARG +2.2 , -1.1
Exposure_Number: 122
Target_Name: ZOD1
Config: FOS/RD
Opmode: ACCUM
Aperture: 1.0-PAIR-A
Sp_Element: G570H
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1500S
Special_Requirements: PAR WITH 121
Comments:
Exposure_Number: 123
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 160S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 124
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 6 -------------
Exposure_Number: 126
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1900S
Special_Requirements: SHADOW
SEQ 126,128 NON-INT
POS TARG +1.1 , -2.2
Exposure_Number: 127
Target_Name: ZOD1
Config: FOS/RD
Opmode: ACCUM
Aperture: 1.0-PAIR-A
Sp_Element: G570H
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1500S
Special_Requirements: PAR WITH 126
Comments:
Exposure_Number: 128
Target_Name: EBL1
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 160S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 129
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments:
!======================================================================
Visits
Visit_Number: 2
Visit_Requirements: BETWEEN 25-NOV-1995:12:00:00 AND 28-NOV-1995:15:00:00
ORIENT 90.0D TO 90.0D FROM 1 ! U3 = 45 degrees
PCS MODE F
On_Hold_Comments:
Visit_Comments: Link to DECON. For maximum sensitivity in the near-UV,
our program would benefit from decontamination close to
and preceding EACH visit.
! -----------Orbit 1 -------------
Exposure_Number: 200
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 400S
Special_Requirements: POS TARG -1.1 , +1.1 ! 11 * 0.10" = 23.91 * 0.046"
LOW-SKY
Exposure_Number: 201
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 200-201 NON-INT
POS TARG +0.0 , +0.0
Exposure_Number: 202
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L ! 4571-6820 \AA
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1300S
Special_Requirements: PAR WITH 201
Comments: This exposure should be simultanious with exposure 201.
and last as long as possible w/o interfering with Exp 201.
Exposure_number: 204
Target_Name: BIAS
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:10
Time_Per_Exposure: 0S
Special_Requirements:
Comments: This should be done while target is occulted.
If data storage is a problem, reduce the # of bias frames.
! -----------Orbit 2 -------------
Exposure_Number: 205
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 400S
Special_Requirements: POS TARG -1.1 , +1.1
LOW-SKY
Exposure_Number: 206
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 205-206 NON-INT
POS TARG -1.1 , +0.0
Exposure_Number: 207
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L ! 4571-6820
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 206
Comments:
Exposure_Number: 209
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 3 -------------
Exposure_Number: 210
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 400S
Special_Requirements: POS TARG -1.1 , +1.1
LOW-SKY
Exposure_Number: 211
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 210-211 NON-INT
POS TARG +0.0 , +1.1
Exposure_Number: 212
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 211
Comments:
Exposure_Number: 214
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 4 -------------
Exposure_Number: 215
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 400S
Special_Requirements: POS TARG -1.1 , +1.1
LOW-SKY
Exposure_Number: 216
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 215-216 NON-INT
POS TARG -2.2 , +2.2
Exposure_Number: 217
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 216
Comments:
Exposure_Number: 219
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 5 -------------
Exposure_Number: 220
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 400S
Special_Requirements: POS TARG -1.1 , +1.1
LOW-SKY
Exposure_Number: 221
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W !
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 220-221 NON-INT
POS TARG -2.2 , +1.1
Exposure_Number: 222
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 221
Comments:
Exposure_Number: 224
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 6 -------------
Exposure_Number: 225
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 400S
Special_Requirements: POS TARG -1.1 , +1.1
LOW-SKY
Exposure_Number: 226
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 225-226 NON-INT
POS TARG -1.1 , +2.2
Exposure_Number: 227
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 226
Comments:
Exposure_Number: 229
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
!=========================================================================
Visits
Visit_Number: 3
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:
Visit_Comments: Link to DECON. For maximum sensitivity in the near-UV,
our program would benefit from decontamination close to
and preceding EACH visit.
! -----------Orbit 1 -------------
Exposure_Number: 300
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 200S
Special_Requirements: POS TARG +1.1 , -1.1 !11 * 0.10" = 23.91 * 0.046"
LOW-SKY
Exposure_Number: 301
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 300-301 NON-INT
POS TARG +0.0 , +0.0
Exposure_Number: 302
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L ! 4571-6820 \AA
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1300S
Special_Requirements: PAR WITH 301
Comments: This exposure should be simultanious with exposure 101.
and last as long as possible w/o interfering with Exp 101.
Exposure_number: 304
Target_Name: BIAS
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:10
Time_Per_Exposure: 0S
Special_Requirements:
Comments: This should be done while target is occulted.
If data storage is a problem, reduce the # of bias frames.
! -----------Orbit 2 -------------
Exposure_Number: 305
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 200S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 306
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F555W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 305-306 NON-INT
POS TARG +1.1 , +0.0
Exposure_Number: 307
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L ! 4571-6820
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 306
Comments:
Exposure_Number: 309
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 3 -------------
Exposure_Number: 310
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 200S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 311
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 310-311 NON-INT
POS TARG +0.0 , -1.1
Exposure_Number: 312
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 311
Comments:
Exposure_Number: 314
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 4 -------------
Exposure_Number: 315
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 200S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 316
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F814W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 315-316 NON-INT
POS TARG +2.2 , -2.2
Exposure_Number: 317
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 316
Comments:
Exposure_Number: 319
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 5 -------------
Exposure_Number: 320
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 200S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 321
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 320-321 NON-INT
POS TARG +2.2 , -1.1
Exposure_Number: 322
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 321
Comments:
Exposure_Number: 324
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
! -----------Orbit 6 -------------
Exposure_Number: 325
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 200S
Special_Requirements: POS TARG +1.1 , -1.1
LOW-SKY
Exposure_Number: 326
Target_Name: EBL2
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL-FIX
Sp_Element: F300W
Wavelength:
Optional_Parameters: CR-SPLIT = NO
ATD-GAIN = 7
Number_of_Iterations: 1
Time_Per_Exposure: 1800S
Special_Requirements: SHADOW
SEQ 325-326 NON-INT
POS TARG +1.1 , -2.2
Exposure_Number: 327
Target_Name: ZOD2
Config: FOS/RD
Opmode: ACCUM
Aperture: 4.3
Sp_Element: G650L
Wavelength:
Optional_Parameters: STEP-PATT = SINGLE
Number_of_Iterations: 1
Time_Per_Exposure: 1460S
Special_Requirements: PAR WITH 326
Comments:
Exposure_Number: 329
Target_Name: DARK
Config: WFPC2
Opmode: IMAGE
Aperture: WFALL
Sp_Element: DEF
Wavelength:
Optional_Parameters: CR-SPLIT=NO, CLOCKS=NO, ATD-GAIN=7
Number_of_iterations:1
Time_Per_Exposure: 1700s
Special_Requirements:
Comments: This should be done while target is occulted.
!==========================================================================
Data_Distribution ! Defaults indicated; change if desired
Medium: 8MM ! 8MM or 6250BPI or 1600BPI
Blocking_Factor: 10 ! 10 or 1
! Only astronomers with very old 9-
! track tape drives should consider
! a blocking factor of 1
Ship_To: PI_Address ! STSCI or PI_Address or <free-text>
! PI Address from Phase I is:
!
! 813 Santa Barbara Street,
! Pasadena, CA 91101
!
!
Ship_Via: UPS ! UPS (2-day) or OVERNIGHT
! Overnight shipping done at PI expense
Recipient_Email: ! Needed if Ship_To: is not PI_Address
! <free-text>
! Let us know what you think of this template and software!
! Please send a list of your likes and dislikes to your Program Coordinator