Technical Instrument Report WFPC2-97-05
Results of the WFPC2 SM-2 Lyman-α
Throughput Check (prop-ID 7018 and
7029)
C. O’Dea, S. Baggett, S. Gonzaga
June 19, 1997
ABSTRACT
The WFPC2 throughput at wavelengths near 1200 Angstroms was monitored over the
period 27-Feb-97 to 05-May-97. The far UV throughput was not significantly affected by
the February 1997 servicing mission. Any change is less than the roughly 20% measurement uncertainty.
1. Introduction
Although WFPC2 was not serviced during the second servicing mission, the SM-2
activities and/or the new instruments could have released significant contaminants into the
HST environment. Thus, it was important to check that the throughput of WPFC2 was
maintained. Several programs were designed to test various aspects of WFPC2 throughput. A suite of filters covering a broad range of wavelengths showed no significant change
(Whitmore et al. 1997). Examination of the throughput at F170W showed that the contamination rates after SM-2 were initially higher than normal, but declined with time (Stiavelli
et al. 1997). A third check was performed to measure the throughput at the shortest wavelengths at which WFPC2 is sensitive -- i.e., around 1200 Angstroms (close to Lyman-α).
A similar program was carried out during the first year of WFPC2 operation to monitor the
far-UV throughput (Mackenty & Baggett 1996). In this TIR we describe the results of the
SM-2 Lyman alpha throughput check (proposal 7018 and its extension 7029).
Observations were made of the UV-bright star WD0310-688 at several epochs in order
to measure any far-UV throughput decrease due to contamination of the WFPC2 pick-off
mirror. The properties of the star are summarized in Table 1. The post-SMOV data was
compared with pre-SMOV data taken on 18-Nov-96. Observations are made in far-UV filters F122M and F160BW. However, both of these filters have a significant red leak. Thus,
images are also taken with these filters crossed with F130LP, so as to isolate counts con-
1
tributed by the red leak in F122M and F160BW. The observations were taken in both the
PC1 and WF3 chips. Two observations were taken in each filter/chip combination. In addition, a F555W image was taken in PC1 as an overall sanity check.
The observations in 7018 consisted of three epochs of observation, each within 1-2
days after a DECON. Because of a delay in the comissioning of the STIS MAMAs, and
the need to continue monitoring far-UV throughput, the program was extended (ID 7029)
for another six epochs at roughly weekly intervals up to 05-May-97.
2. Procedure
A rapid turnaround was not required for these results, so the data were calibrated via
the normal pipeline procedures. Because a flat field reference file is not available for the
filters crossed with F130LP, a crude flat field was applied in three ways and the results
compared, (1) these data were flatfielded with a dummy file of unity value, (2) they were
corrected by hand using a local median filtered flat field value from the uncrossed filter
flatfield, and (3) recalibrated using the flat field from the uncrossed filter. The data were
reduced by Gonzaga using scripts initially created by Christine Ritchie and modified by
Gonzaga. Selected data sets were analysed independently by O’Dea and Baggett, obtaining consistent results. The two observations in each filter/chip combination were reduced
separately and the results compared afterwards. Cosmic rays were removed by hand and
the centers of the stars were determined by eye due to asymmetries in the PSF. O’Dea also
reduced selected data implementing CR removal with crrej and obtained similar results.
The stars were checked for saturation with none found. Aperture photometry was obtained
with the task “phot” using an aperture radius of 0.5 arcsec (5 pixels in WF3 and 11 pixels
in PC1) and a sky subtraction annulus between 1.5 and 2.0 arcsec.
The count rates in the F130LP crossed filters (the red counts) were subtracted from the
uncrossed filters (the total counts) to produce the “approximate” red leak corrected (blue)
count rates.
Notes and Caveats
In this section we note various features of the data, some of which may affect the
uncertainties of the results.
Note that some of the filter/chip combinations were not observed on the pre-SM-2
visit, thus for them, a pre/post SM-2 comparison is not possible.
The flat fields for the F122M and F160BW filters are somewhat uncertain since they
are based on ground TV data and no on-orbit calibrations are available. Hot pixels appear
to be present in the flatfields. There are no flat fields available for the filters crossed with
F130LP and we instead used flat field values for the uncrossed filters. There is a significant
red leak (over 70% of the light from our white dwarf calibration star WD0310-688
2
through the F122M and F160BW filters is due to red leak). Thus, the flat field response in
the F122M and F160BW filters is dominated by the red component, yet we are trying to
measure the blue component of the light through the filter. The uncertainty in the flat fields
is relevant because of a large shift in position on the chip between the pre-SM-2 and postSM-2 observations of the standard star, i.e., in the PC the star is located near 455, 560 in
the the pre-SM2 observation and near 530, 326 in the post-SM-2 observations.
There is a ghost in the WF3 F122MxF130LP image to the upper right of the star.
There is a bad column (a trap - see Whitmore & Wiggs 1995) at x=529 in the PC which is
at the location of the star in the post-SM-2 data. No attempt was made to mask out the bad
column.
Table 2 gives the x, y pixel locations of the star in the different filter/chip combinations. On the PC the star position in the UV filters differs by 2-3 pixels from the position in
the F555W filter. Crossing the UV filters with the F130LP results in an additional position
shift of the star of about 4.5 pixels in x and 1.4 pixels in y, i.e., a total angular shift of
about 0.2 arcsec. Since the bad column in the PC was at x=528, the star’s motion on the
chip from one filter to the next introduced errors in the red leak correction.
3. Results
Plots of the normalized ratios of the count rates are given in Figures 1-5. The countrates are normalized to the 26-Apr-97 values which were obtained less than 4 hrs after a
decontamination. The statistics of the normalized count rates are given in Table 3 and the
individual measurements of the count rates are given in Table 4. Figure 1 shows the normalized count rates for the F555W filter on the PC. These observations are consistent with
the typical 2% repeatibility and show that the instrument was well behaved during these
observations. There may also be a long term trend for a small increase in normalized countrate with time. This effect is under investigation. Figure 2 shows the count rates in the
F122M and F160BW filters for both PC and WF3. These observations show no significant
trend with time, but show a scatter of ~7%. The normalized count rates for the F122M and
F160BW crossed with the F130LP are shown in Figures 3 (PC) and 4 (WF3) with and
without a flat field correction applied. These data are also consistent with no general trend
in the data, but show a scatter of 5-10% in the PC and WF3. The WF3 data in Figure 4 hint
at a decrease in normalized countrate with time, but this is not confirmed by the other data
and is probably due to the large scatter. A comparison of the uncrossed and crossed filter
countrates shows that the red leak contribution is high for this star, roughly 70% (see Table
1). Thus in Figure 5 we show the count rates with an approximate correction for the red
leak. These results are again consistent with no general trend in the throughput, but with a
large scatter of ~15-25%. While it is clear that the data have much scatter, it is clear that
the pre-SM-2 (MJD ~ 50404) and post-SM-2 (MJD 50500-50600) results show good
agreement on the PC in Figure 5. Thus, we conclude that the far-UV throughput of
3
WFPC2 was not significantly affected by contamination due to the second servicing mission. Any change is less than the ~20% uncertainty.
Table 1: Properties of WD0310-688 (LB3303) in March 1997
Property
Value
RA (J2000.0)
3:10:30.970
DEC (J2000.0)
-68:36:03.05
Type
DA3
F555W (STMAG) in 0.5” aperture
12.3
B-V
0.02
U-B
-0.62
Avg count rate F555W
13140 DN/s
Avg count rate F122M
39 DN/s
Redleak Fraction in F122M
72%
Avg count rate F160BW
142 DN/s
Redleak Fraction in F160BW
78%
Table 2: Location of Star on Chip and Integration Time
Chip
PC1
x
y
Integration
Time (s)
532.19
326.98
100.0
527.73
325.66
100.0
533.22
328.28
40.0
528.68
326.84
40.0
F555W
531.92
328.87
0.5
F122M
384.00
469.00
100.0
380.95
464.66
100.0
385.10
470.11
40.0
382.20
465.81
40.0
Filter1
Filter2
F122M
F122M
F130LP
F160BM
F160BM
WF3
F122M
F130LP
F130LP
F160BM
F160BM
F130LP
4
Table 3 contains the count rates normalized to the value on 26-Apr-97 which was taken
less than 4 hrs after a decontamination.
Table 3. Normalized Count rates
chip
filter1
filter2
ff
npts
mean
rms
median
min
max
PC
F555W
none
y
10
0.985
0.014
0.991
0.959
1.000
PC
F122M
none
y
18
0.940
0.064
0.933
0.843
1.128
PC
F122M
F130LP
y
16*
0.960
0.030
0.967
0.895
1.004
PC
F122M
F130LP
n
18
0.964
0.030
0.963
0.893
1.007
PC
F122M
none(r)
y
18
0.893
0.142
0.873
0.715
1.372
PC
F160BW
none
y
18
0.958
0.068
0.956
0.825
1.070
PC
F160BW
F130LP
y
16*
0.889
0.056
0.880
0.820
1.000
PC
F160BW
F130LP
n
18
0.978
0.041
0.982
0.886
1.028
PC
F160BW
none(r)
y
18
1.311
0.385
1.415
0.850
2.099
WF3
F160BW
none
y
16
0.938
0.074
0.938
0.791
1.042
WF3
F160BW
F130LP
y
16
0.974
0.067
0.973
0.865
1.075
WF3
F160BW
F130LP
n
16
1.005
0.126
0.987
0.855
1.223
WF3
F160BW
none(r)
y
16
0.850
0.109
0.861
0.615
1.009
WF3
F122M
none
y
17**
0.911
0.074
0.927
0.791
1.003
WF3
F122M
F130LP
y
16
0.914
0.071
0.928
0.796
1.012
WF3
F122M
F130LP
n
16
0.923
0.068
0.934
0.813
1.020
WF3
F122M
none(r)
y
17**
0.851
0.245
0.876
0.000
1.101
Notes to Table 3.
Flat fielded for crossed filters means flat for uncrossed filter was applied.
* Two fewer flat fielded observations: November 1996 data not reprocessed with flat.
** No other WF3 observations done in November, just one image of WF3,F122M.
(r) in filter2 column indicates stats for red leak corrected values.
5
In Table 4, the flags “t, r, or m” mean that pipeline calibration was applied, i.e., with no
flatfield correction applied to the crossed filter data.The flag “f” means that the flat field
for the uncrossed filter was applied to the data.
Table 4: Count rates
countrate
per sec
error
Date
dd/mm/yy
MJD
Flag
Aper
pixels
none
12918.
48.77
17/11/96
50404.8884
t
11.
F555W
none
13122.
48.66
17/11/96
50404.8898
t
11.
1
F160BW
none
130.14
0.56
17/11/96
50404.8919
t
11.
1
F160BW
none
130.02
0.55
17/11/96
50404.8932
t
11.
1
F160BW
F130LP
106.27
0.52
17/11/96
50404.896
t
11.
1
F160BW
F130LP
108.74
0.52
17/11/96
50404.8974
t
11.
1
F170W
none
331.44
1.20
17/11/96
50404.8995
t
11.
1
F170W
none
335.43
1.21
17/11/96
50404.9009
t
11.
1
F122M
none
40.14
0.20
17/11/96
50404.903
t
11.
1
F122M
none
38.23
0.19
17/11/96
50404.9051
t
11.
1
F122M
F130LP
26.77
0.17
17/11/96
50404.9085
t
11.
1
F122M
F130LP
26.72
0.17
17/11/96
50404.9106
t
11.
3
F122M
none
36.07
0.17
17/11/96
50404.9148
t
5.
1
F122M
none
39.44
0.20
27/02/97
50506.8904
r
11.
1
F122M
none
39.74
0.20
27/02/97
50506.8925
r
11.
1
F122M
F130LP
27.53
0.18
27/02/97
50506.896
r
11.
1
F122M
F130LP
27.49
0.18
27/02/97
50506.8981
r
11.
1
F122M
F130LP
25.66
0.18
27/02/97
50506.896
f
11.
1
F122M
F130LP
25.64
0.18
27/02/97
50506.8981
f
11.
1
F160BW
none
144.28
0.57
27/02/97
50506.9009
r
11.
1
F160BW
none
146.15
0.57
27/02/97
50506.9023
r
11.
1
F160BW
F130LP
111.54
0.52
27/02/97
50506.905
m
11.
1
F160BW
F130LP
111.61
0.52
27/02/97
50506.9064
r
11.
1
F160BW
F130LP
107.59
0.52
27/02/97
50506.905
f
11.
1
F160BW
F130LP
107.57
0.52
27/02/97
50506.9064
f
11.
Chip
Filter1
Filter2
1
F555W
1
6
Table 4: Count rates
countrate
per sec
error
Date
dd/mm/yy
MJD
Flag
Aper
pixels
none
13231.
47.98
27/02/97
50506.9613
r
11.
F122M
none
39.15
0.17
27/02/97
50506.9099
r
5.
3
F122M
none
39.34
0.17
27/02/97
50506.912
r
5.
3
F122M
F130LP
25.87
0.14
27/02/97
50506.9154
r
5.
3
F122M
F130LP
25.45
0.14
27/02/97
50506.9495
r
5.
3
F122M
F130LP
25.83
0.14
27/02/97
50506.9154
5.
3
F122M
F130LP
25.41
0.14
27/02/97
50506.9495
5.
3
F160BW
none
123.25
0.48
27/02/97
50506.9523
5.
3
F160BW
none
126.24
0.49
27/02/97
50506.9536
5.
3
F160BW
F130LP
97.13
0.43
27/02/97
50506.9564
5.
3
F160BW
F130LP
100.28
0.44
27/02/97
50506.9578
5.
3
F160BW
F130LP
91.63
0.43
27/02/97
50506.9564
5.
3
F160BW
F130LP
94.64
0.45
27/02/97
50506.9578
5.
1
F122M
none
46.56
0.21
4/03/97
50511.5661
11.
1
F122M
none
39.19
0.19
4/03/97
50511.5682
11.
1
F122M
F130LP
28.21
0.18
4/03/97
50511.5717
11.
1
F122M
F130LP
27.75
0.18
4/03/97
50511.5738
11.
1
F122M
F130LP
26.13
0.18
4/03/97
50511.5717
11.
1
F122M
F130LP
25.72
0.18
4/03/97
50511.5738
11.
1
F160BW
none
137.28
0.56
4/03/97
50511.5766
11.
1
F160BW
none
139.19
0.56
4/03/97
50511.5779
11.
1
F160BW
F130LP
110.55
0.52
4/03/97
50511.5807
11.
1
F160BW
F130LP
111.79
0.53
4/03/97
50511.5821
11.
1
F160BW
F130LP
103.83
0.52
4/03/97
50511.5807
11.
1
F160BW
F130LP
104.79
0.53
4/03/97
50511.5821
11.
Chip
Filter1
Filter2
1
F555W
3
7
Table 4: Count rates
countrate
per sec
error
Date
dd/mm/yy
MJD
none
13025.
48.53
4/03/97
50511.6328
11.
F122M
none
37.60
0.17
4/03/97
50511.5856
5.
3
F122M
none
38.80
0.17
4/03/97
50511.5877
5.
3
F122M
F130LP
26.59
0.15
4/03/97
50511.5911
5.
3
F122M
F130LP
27.21
0.15
4/03/97
50511.6085
5.
3
F122M
F130LP
26.57
0.15
4/03/97
50511.5911
5.
3
F122M
F130LP
27.19
0.15
4/03/97
50511.6085
5.
3
F160BW
none
128.47
0.49
4/03/97
50511.6113
r
5.
3
F160BW
none
130.02
0.49
4/03/97
50511.6127
r
5.
3
F160BW
F130LP
97.12
0.43
4/03/97
50511.6154
r
5.
3
F160BW
F130LP
98.61
0.43
4/03/97
50511.6168
r
5.
3
F160BW
F130LP
93.37
0.43
4/03/97
50511.6154
f
5.
3
F160BW
F130LP
94.65
0.43
4/03/97
50511.6168
f
5.
1
F122M
none
37.26
0.19
28/03/97
50535.005
r
11.
1
F122M
none
37.29
0.19
28/03/97
50535.0071
r
11.
1
F122M
F130LP
26.96
0.18
28/03/97
50535.0106
r
11.
1
F122M
F130LP
26.77
0.18
28/03/97
50535.0127
r
11.
1
F122M
F130LP
25.05
0.17
28/03/97
50535.0106
f
11.
1
F122M
F130LP
24.84
0.17
28/03/97
50535.0127
f
11.
1
F160BW
none
153.18
0.59
28/03/97
50535.0154
r
11.
1
F160BW
none
154.60
0.59
28/03/97
50535.0168
r
11.
1
F160BW
F130LP
106.56
0.52
28/03/97
50535.0196
r
11.
1
F160BW
F130LP
106.66
0.51
28/03/97
50535.021
r
11.
1
F160BW
F130LP
105.49
0.50
28/03/97
50535.0196
f
11.
1
F160BW
F130LP
105.29
0.50
28/03/97
50535.021
f
11.
1
F555W
none
13341.
48.85
28/03/97
50535.1384
r
11.
3
F122M
none
32.15
0.16
28/03/97
50535.0717
r
5.
Chip
Filter1
Filter2
1
F555W
3
8
Flag
Aper
pixels
Table 4: Count rates
countrate
per sec
error
Date
dd/mm/yy
MJD
Flag
Aper
pixels
none
32.75
0.16
28/03/97
50535.0738
r
5.
F122M
F130LP
23.49
0.14
28/03/97
50535.0773
r
5.
3
F122M
F130LP
23.51
0.14
28/03/97
50535.0821
r
5.
3
F122M
F130LP
23.18
0.14
28/03/97
50535.0773
f
5.
3
F122M
F130LP
23.21
0.14
28/03/97
50535.0821
f
5.
3
F160BW
none
113.14
0.47
28/03/97
50535.0849
r
5.
3
F160BW
none
114.71
0.46
28/03/97
50535.0863
r
5.
3
F160BW
F130LP
80.46
0.40
28/03/97
50535.0891
r
5.
3
F160BW
F130LP
81.88
0.40
28/03/97
50535.0904
r
5.
3
F160BW
F130LP
81.58
0.40
28/03/97
50535.0891
f
5
3
F160BW
F130LP
83.02
0.40
28/03/97
50535.0904
f
5.
1
F122M
none
37.39
0.19
11/04/97
50549.8543
r
11.
1
F122M
none
37.53
0.19
11/04/97
50549.8564
r
11.
1
F122M
F130LP
25.49
0.17
11/04/97
50549.8599
f
11.
1
F122M
F130LP
26.99
0.18
11/04/97
50549.8599
r
11.
1
F122M
F130LP
25.37
0.17
11/04/97
50549.862
f
11.
1
F122M
F130LP
26.86
0.18
11/04/97
50549.862
r
11.
1
F160BW
none
134.52
0.56
11/04/97
50549.8648
r
11.
1
F160BW
none
134.40
0.55
11/04/97
50549.8661
r
11.
1
F160BW
F130LP
99.45
0.50
11/04/97
50549.8689
f
11.
1
F160BW
F130LP
103.66
0.51
11/04/97
50549.8689
r
11.
1
F160BW
F130LP
101.39
0.50
11/04/97
50549.8703
f
11.
1
F160BW
F130LP
105.78
0.52
11/04/97
50549.8703
r
11.
1
F555W
none
13341.36
48.23
11/04/97
50549.9411
r
11.
3
F122M
none
36.64.
0.17
11/04/97
50549.9189
r
5
3
F122M
none
37.22
0.17
11/04/97
50549.921
r
5.
Chip
Filter1
Filter2
3
F122M
3
9
Table 4: Count rates
Chip
Filter1
Filter2
countrate
per sec
error
Date
dd/mm/yy
MJD
Flag
Aper
pixels
3
F122M
F130LP
24.28
0.14
11/04/97
50549.9245
f
5.
3
F122M
F130LP
24.2
0.14
11/04/97
50549.9245
r
5.
3
F122M
F130LP
24.48
0.14
11/04/97
50549.9293
f
5.
3
F122M
F130LP
24.39
0.14
11/04/97
50549.9293
r
5.
3
F160BW
none
114.50
0.47
11/04/97
50549.9321
r
5.
3
F160BW
none
115.98
0.47
11/04/97
50549.9335
r
5.
3
F160BW
F130LP
81.96
0.40
11/04/97
50549.9363
f
5.
3
F160BW
F130LP
79.14
0.39
11/04/97
50549.9363
r
5.
3
F160BW
F130LP
84.33
0.41
11/04/97
50549.9377
f
5.
3
F160BW
F130LP
81.36
0.40
11/04/97
50549.9377
r
5.
1
F122M
none
34.77
0.19
19/04/97
50557.9182
m
11.
1
F122M
none
35.18
0.19
19/04/97
50557.9203
m
11.
1
F122M
F130LP
24.12
0.17
19/04/97
50557.9238
f
11.
1
F122M
F130LP
25.56
0.17
19/04/97
50557.9238
m
11.
1
F122M
F130LP
23.62
0.17
19/04/97
50557.9259
f
11.
1
F122M
F130LP
25.00
0.18
19/04/97
50557.9259
m
11.
1
F555W
none
13353.
48.33
19/04/97
50557.9898
m
11.
1
F160BW
none
119.23
0.54
19/04/97
50557.9286
m
11.
1
F160BW
none
120.45
0.54
19/04/97
50557.93
m
11.
1
F160BW
F130LP
99.26
0.50
19/04/97
50557.9328
f
11.
1
F160BW
F130LP
96.29
0.50
19/04/97
50557.9328
m
11.
1
F160BW
F130LP
100.09
0.50
19/04/97
50557.9342
f
11.
1
F160BW
F130LP
97.01
0.50
19/04/97
50557.9342
m
11.
3
F122M
none
31.27
0.16
19/04/97
50557.9377
m
5.
3
F122M
none
31.74
0.16
19/04/97
50557.9398
m
5.
3
F122M
F130LP
21.48
0.14
19/04/97
50557.9432
f
5.
3
F122M
F130LP
21.80
0.13
19/04/97
50557.9432
m
5.
10
Table 4: Count rates
Chip
Filter1
Filter2
countrate
per sec
error
Date
dd/mm/yy
MJD
Flag
Aper
pixels
3
F122M
F130LP
21.38
0.13
19/04/97
50557.9779
f
5.
3
F122M
F130LP
21.68
0.13
19/04/97
50557.9779
m
5.
3
F160BW
none
98.72
0.44
19/04/97
50557.9807
m
5.
3
F160BW
none
101.58
0.44
19/04/97
50557.9821
m
5.
3
F160BW
F130LP
76.14
0.39
19/04/97
50557.9849
f
5.
3
F160BW
F130LP
71.19
0.37
19/04/97
50557.9849
m
5.
3
F160BW
F130LP
77.20
0.39
19/04/97
50557.9863
f
5.
3
F160BW
F130LP
72.11
0.37
19/04/97
50557.9863
m
5.
1
F122M
none
41.08
0.20
26/04/97
50564.1078
m
11.
1
F122M
none
41.46
0.20
26/04/97
50564.1099
m
11.
1
F122M
F130LP
26.28
0.17
26/04/97
50564.1134
f
11.
1
F122M
F130LP
27.87
0.17
26/04/97
50564.1134
m
11.
1
F122M
F130LP
26.47
0.17
26/04/97
50564.1154
f
11.
1
F122M
F130LP
28.13
0.18
26/04/97
50564.1154
m
11.
1
F555W
none
13464.8
48.31
26/04/97
50564.2411
m
11.
1
F160BW
none
144.11
0.57
26/04/97
50564.1182
m
11.
1
F160BW
none
144.94
0.57
26/04/97
50564.1196
m
11.
1
F160BW
F130LP
121.00
0.53
26/04/97
50564.1224
f
11.
1
F160BW
F130LP
108.84
0.51
26/04/97
50564.1224
m
11.
1
F160BW
F130LP
121.12
0.53
26/04/97
50564.1238
f
11.
1
F160BW
F130LP
108.64
0.52
26/04/97
50564.1238
m
11.
3
F122M
none
44.71
0.21
26/04/97
50564.171
m
11.
3
F122M
none
45.46
0.21
26/04/97
50564.1731
m
11.
3
F122M
F130LP
30.28
0.18
26/04/97
50564.1766
f
11.
3
F122M
F130LP
30.12
0.18
26/04/97
50564.1766
m
11.
3
F122M
F130LP
30.79
0.18
26/04/97
50564.1814
f
11.
3
F122M
F130LP
30.59
0.18
26/04/97
50564.1814
m
11.
11
Table 4: Count rates
countrate
per sec
error
Date
dd/mm/yy
MJD
Flag
Aper
pixels
none
139.32
0.59
26/04/97
50564.1842
m
11.
F160BW
none
141.12
0.59
26/04/97
50564.1856
m
11.
3
F160BW
F130LP
97.36
0.51
26/04/97
50564.1884
f
11.
3
F160BW
F130LP
90.53
0.48
26/04/97
50564.1884
m
11.
3
F160BW
F130LP
98.63
0.52
26/04/97
50564.1898
f
11.
3
F160BW
F130LP
91.79
0.49
26/04/97
50564.1898
m
11.
3
F122M
none
39.41
0.18
26/04/97
50564.171
m
5.
3
F122M
none
39.63
0.18
26/04/97
50564.1731
m
5.
3
F122M
F130LP
26.67
0.15
26/04/97
50564.1766
f
5.
3
F122M
F130LP
26.47
0.15
26/04/97
50564.1766
m
5.
3
F122M
F130LP
27.06
0.15
26/04/97
50564.1814
f
5.
3
F122M
F130LP
26.87
0.15
26/04/97
50564.1814
m
5.
3
F160BW
none
123.71
0.49
26/04/97
50564.1842
m
5.
3
F160BW
none
125.78
0.49
26/04/97
50564.1856
m
5.
3
F160BW
F130LP
87.34
0.42
26/04/97
50564.1884
f
5.
3
F160BW
F130LP
81.36
0.40
26/04/97
50564.1884
m
5.
3
F160BW
F130LP
88.72
0.42
26/04/97
50564.1898
f
5.
3
F160BW
F130LP
82.64
0.40
26/04/97
50564.1898
m
5.
1
F122M
none
39.12
0.19
28/04/97
50566.9016
m
11.
1
F122M
none
38.76
0.19
28/04/97
50566.9036
m
11.
1
F122M
F130LP
25.99
0.17
28/04/97
50566.9071
f
11.
1
F122M
F130LP
27.57
0.17
28/04/97
50566.9071
m
11.
1
F122M
F130LP
25.52
0.17
28/04/97
50566.9092
f
11.
1
F122M
F130LP
27.06
0.18
28/04/97
50566.9092
m
11.
1
F555W
none
13440.
48.44
28/04/97
50566.9432
m
11.
1
F160BW
none
145.21
0.58
28/04/97
50566.912
m
11.
Chip
Filter1
Filter2
3
F160BW
3
12
Table 4: Count rates
countrate
per sec
error
Date
dd/mm/yy
MJD
Flag
Aper
pixels
none
145.34
0.58
28/04/97
50566.9134
m
11.
F160BW
F130LP
110.87
0.52
28/04/97
50566.9161
f
11.
1
F160BW
F130LP
106.95
0.52
28/04/97
50566.9161
m
11.
1
F160BW
F130LP
111.48
0.52
28/04/97
50566.9175
f
11.
1
F160BW
F130LP
107.94
0.52
28/04/97
50566.9175
m
11.
3
F122M
none
42.07
0.21
28/04/97
50566.921
m
11.
3
F122M
none
42.07
0.21
28/04/97
50566.9231
m
11.
3
F122M
F130LP
29.19
0.18
28/04/97
50566.9266
f
11.
3
F122M
F130LP
29.21
0.18
28/04/97
50566.9266
m
11.
3
F122M
F130LP
28.92
0.18
28/04/97
50566.9314
f
11.
3
F122M
F130LP
28.95
0.18
28/04/97
50566.9314
m
11.
3
F160BW
none
133.29
0.58
28/04/97
50566.9342
m
11.
3
F160BW
none
134.15
0.58
28/04/97
50566.9356
m
11.
3
F160BW
F130LP
97.18
0.52
28/04/97
50566.9384
f
11.
3
F160BW
F130LP
85.74
0.48
28/04/97
50566.9384
m
11.
3
F160BW
F130LP
98.54
0.52
28/04/97
50566.9398
f
11.
3
F160BW
F130LP
87.01
0.48
28/04/97
50566.9398
m
11.
3
F122M
none
36.47
0.17
28/04/97
50566.921
m
5.
3
F122M
none
36.95
0.17
28/04/97
50566.9231
m
5.
3
F122M
F130LP
25.40
0.14
28/04/97
50566.9266
f
5.
3
F122M
F130LP
25.42
0.14
28/04/97
50566.9266
m
5.
3
F122M
F130LP
25.40
0.14
28/04/97
50566.9314
f
5.
3
F122M
F130LP
25.42
0.14
28/04/97
50566.9314
m
5.
3
F160BW
none
118.03
0.48
28/04/97
50566.9342
m
5.
3
F160BW
none
119.01
0.48
28/04/97
50566.9356
m
5.
3
F160BW
F130LP
86.94
0.42
28/04/97
50566.9384
f
5.
3
F160BW
F130LP
76.49
0.39
28/04/97
50566.9384
m
5.
Chip
Filter1
Filter2
1
F160BW
1
13
Table 4: Count rates
Chip
Filter1
Filter2
countrate
per sec
error
Date
dd/mm/yy
MJD
Flag
Aper
pixels
3
F160BW
F130LP
87.90
0.42
28/04/97
50566.9398
f
5.
3
F160BW
F130LP
77.41
0.39
28/04/97
50566.9398
m
5.
1
F122M
none
37.60
0.20
5/05/97
50573.2807
m
11.
1
F122M
none
37.50
0.20
5/05/97
50573.2828
m
11.
1
F122M
F130LP
24.73
0.17
5/05/97
50573.2863
f
11.
1
F122M
F130LP
26.37
0.18
5/05/97
50573.2863
m
11.
1
F122M
F130LP
24.66
0.17
5/05/97
50573.2884
f
11.
1
F122M
F130LP
26.25
0.18
5/05/97
50573.2884
m
11.
1
F555W
none
13365.
48.11
5/05/97
50573.3606
m
11.
1
F160BW
none
134.03
0.56
5/05/97
50573.2911
m
11.
1
F160BW
none
134.77
0.56
5/05/97
50573.2925
m
11.
1
F160BW
F130LP
110.97
0.52
5/05/97
50573.2953
f
11.
1
F160BW
F130LP
102.05
0.51
5/05/97
50573.2953
m
11.
1
F160BW
F130LP
112.51
0.51
5/05/97
50573.2967
f
11.
1
F160BW
F130LP
103.94
0.50
5/05/97
50573.2967
m
11.
3
F122M
none
33.33
0.16
5/05/97
50573.3384
m
5.
3
F122M
none
33.60
0.16
5/05/97
50573.3404
m
5.
3
F122M
F130LP
22.59
0.14
5/05/97
50573.3439
f
5.
3
F122M
F130LP
22.54
0.14
5/05/97
50573.3439
m
5.
3
F122M
F130LP
22.97
0.14
5/05/97
50573.3488
f
5.
3
F122M
F130LP
22.97
0.14
5/05/97
50573.3488
m
5.
3
F160BW
none
108.34
0.47
5/05/97
50573.3516
m
5.
3
F160BW
none
109.95
0.47
5/05/97
50573.3529
m
5.
3
F160BW
F130LP
80.98
0.40
5/05/97
50573.3557
f
5.
3
F160BW
F130LP
70.14
0.37
5/05/97
50573.3557
m
5.
3
F160BW
F130LP
81.43
0.40
5/05/97
50573.3571
f
5.
3
F160BW
F130LP
70.66
0.37
5/05/97
50573.3571
m
5.
14
Figure 1: Normalized countrates for the PC F555W observations. Dotted lines represent
DECON dates.
PC, F555W
1.4
normalized countrate
1.2
1
.8
.6
50400
50450
50500
MJD
15
50550
50600
Figure 2: Normalized count rates for F122M and F160BW in PC (left) and WF3 (right).
Dotted lines represent DECON dates.
WF3, F160BW
1.4
1.2
1.2
normalized countrate
normalized countrate
PC, F160BW
1.4
1
.8
1
.8
.6
.6
50400
50450
50500
MJD
50550
50600
50400
50450
50550
50600
50550
50600
WF3, F122M
1.4
1.4
1.2
1.2
normalized countrate
normalized countrate
PC, F122M
50500
MJD
1
.8
1
.8
.6
.6
50400
50450
50500
MJD
50550
50600
50400
16
50450
50500
MJD
Figure 3: Normalized Count rates in F122M and B160BW crossed with the F130LP in
the PC with flat field (of uncrossed filter) applied (left) and not applied (right). Dotted
lines represent DECON dates.
PC, F160BW+F130LP, no flat
1.4
1.2
1.2
normalized countrate
normalized countrate
PC, F160BW+F130LP
1.4
1
.8
1
.8
.6
.6
50400
50450
50500
MJD
50550
50600
50400
50500
MJD
50550
50600
PC, F122M+F130LP, no flat
1.4
1.4
1.2
1.2
normalized countrate
normalized countrate
PC, F122M+F130LP
50450
1
.8
1
.8
.6
.6
50400
50450
50500
MJD
50550
50600
50400
17
50450
50500
MJD
50550
50600
Figure 4: Normalized Count rates through F122M and F160BW crossed with F130LP in
WF3 with flat field (of uncrossed filter) applied (left) and not applied (right). Dotted lines
represent DECON dates.
WF3, F160BW+F130LP, no flat
1.4
1.2
1.2
normalized countrate
normalized countrate
WF3, F160BW+F130LP
1.4
1
.8
1
.8
.6
.6
50400
50450
50500
MJD
50550
50600
50400
50500
MJD
50550
50600
WF3, F122M+F130LP, no flat
1.4
1.4
1.2
1.2
normalized countrate
normalized countrate
WF3, F122M+F130LP
50450
1
.8
1
.8
.6
.6
50400
50450
50500
MJD
50550
50600
50400
18
50450
50500
MJD
50550
50600
Table 5. Redleak corrected normalized count rates through F160BW and F122M in the
PC (left) and WF3 (right). Dotted lines represent DECON dates.
WF3, F160BW, redleak corrected
2
1.5
1.5
normalized countrate
normalized countrate
PC, F160BW, redleak corrected
2
1
.5
1
.5
0
0
50400
50450
50500
MJD
50550
50600
50400
50500
MJD
50550
50600
WF3, F122M, redleak corrected
2
2
1.5
1.5
normalized countrate
normalized countrate
PC, F122M, redleak corrected
50450
1
.5
1
.5
0
0
50400
50450
50500
MJD
50550
50600
50400
50450
50500
MJD
50550
50600
Acknowledgements
We are grateful to John Biretta for writing this SMOV proposal, for his diligent efforts
to coordinate WFPC2 SMOV, and for comments on the TIR. We thank Brad Whitmore
and Inge Heyer for comments on the TIR.
19
References
Mackenty, J. W., Baggett, S., WFPC2 ISR 96-07
Stiavelli, M., Biretta, J., Baggett, S., Gonzaga, S., Mutchler, M., WFPC2 TIR 97-02
Whitmore, B., Gonzaga, S., Heyer, I., WFPC2 TIR 97-01
Whitmore, B., Wiggs, M., WFPC2 ISR 95-03
20