Instrument Science Report STIS 2000-03
Sensitivity Monitor Report for
the STIS First-Order Modes -II
Ed Smith, David Stys, Nolan Walborn and Ralph Bohlin
September 21, 2000
ABSTRACT
An analysis of all low and medium resolution observations of the STIS Sensitivity
Monitoring Programs made prior to December 1999 shows continuation of trends correlated with temperature and with time. We provide the first detailed report on additional
trends in sensitivities revealed by the medium resolution modes of the instrument.
Only the G750L mode shows no significant variation in sensitivity. All other modes,
when averaged over a broad band of the wavelength coverage of each, show evidence for
an ~1%/yr decline, except for G140L and G230L (after ~1998.7) being ~1.4%/yr, G140M
being ~2.5%/yr, and G430L declining at ~0.5%/yr.
A bimodal, before and after ~1998.7, trend previously found in the G230L is found in
the NUV-MAMA G230M. Similar trends are also evident in the CCD in the G230LB and
the two G230MB monitoring modes.
The temperature dependence of the sensitivity in the G140M modes is found to be consistent with the -0.25%/˚C correlation measured in the G140L mode.
The mean “relative gain”, gain1/gain4, of the CCD between 1998.3 and 1999.7 was
4.039 ±0.006 and did not change significantly in that period.
Recommendations are made for changes in the ‘pipeline’ calibration software to correct for the time and temperature variations in all L modes and in the M modes of both
MAMA detectors.
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Instrument Science Report STIS 2000-03
1. Introduction
This is an update to the analyses of the sensitivity monitoring observations of the STIS
first order modes. In particular, we report on trends in sensitivities of the medium resolution modes of the instrument. The analyses now include all Cycle 7 data and all Cycle 8
observations made prior to the November-December 1999 gyro failure and servicing mission hiatus. Prior reports of sensitivity trends measured using these monitor programs
were given by Walborn and Bohlin in ISR STIS 98-27 (WB1998) and by Bohlin in ISR
STIS 99-07 (B1999).
2. Observations
Appendix 1 lists all data obtained by the STIS sensitivity monitoring proposal’s low
resolution (L) and medium resolution (M) modes. The NUV-MAMA and FUV-MAMA L
mode observations are of GRW+70D5824, while all MAMA M mode and all CCD exposures are of AGK+81D266. The data are from CAL/STIS proposals 7673 and 8424 for the
MAMA detectors and proposals 7672 and 8418 for the CCD. Sufficient data points are
now available from these programs that we do not include measures of other standard reference stars, nor measurements from other STIS observing programs.
All observations are taken using the 52X2 slit. All CCD data are CR-SPLIT=2 and
GAIN=1. Except that, beginning in March, 1998, both a GAIN=1 and a GAIN=4 exposure
is made for each visit of the G430M at the 4194 Å central wavelength setting. The MAMA
L modes are monitored monthly while the M mode measures are taken at two month intervals. The CCD L modes are also monitored at two month intervals while the CCD M
modes are checked every four months. G750L and G750M observations have contemporaneous ‘fringe-flat’ exposures. The normal MSM shifting is disabled for these monitoring
observations in order to minimize variations due to spatial displacements of the spectra. To
see spectra representative of those produced by each mode in this program please refer to
Figures 1-10 of WB1998.
Position change (+3˝ to -3˝) of FUV-MAMA spectra.
On March 15, 1999, the default position of the first order mode spectra on the FUVMAMA detector [i.e., G140L and M spectra] was changed from a position ~+3˝ above the
center line of the detector to a position at -3˝. This moves the spectra away from the
higher dark counts present in the ‘upper left’ region of the detector. The off-center positioning is desired in order to avoid the Repeller Wire that is positioned across the center of
the detector. In section 3b we describe the changes in the monitoring analyses due to the
change in position of the spectra.
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Instrument Science Report STIS 2000-03
3. Data Reduction and Analysis.
All data were calibrated with STSDAS CALSTIS Version 2.6 using the most recent
updates to the various calibration reference files (bias, dark, etc) as of March 15, 2000.
The NET counts for each spectrum are extracted from the X1D product for analysis of the
MAMA data and the SX1 product for the CCD analysis. Small offsets in wavelength coverage in a given mode induced by small variations in position of the spectra on the detector
are dealt with by extracting a consistent wavelength range for each mode. Problematic
wavelength regions such as geo-coronal Lyman Alpha and G750L fringing are also
avoided by the choice of the wavelength passbands being extracted. Those passbands are
listed in TABLE 1.
Our analyses of sensitivity changes vs time will be made relative to the
Two additional steps in reduction of the FUV-MAMA data are applied. There is a correction applied to account for variations in sensitivity that correlate with temperature.
Also, all data recorded with the spectra at the -3˝, ‘below-the-repeller-wire’ position on the
detector are corrected for the difference in sensitivity at that position relative to the +3˝
position. After those steps, descibed below, we examine trends in the “relative sensitivity”, i.e the sensitivity relative to a reference spectrum. For each mode that reference is the
first observation in the series for that mode, and for the FUV-MAMA the reference spectrum is at the +3˝ position on the detector at a detector temperature of 36˚C.
3a. FUV-MAMA: Correction for Temperature dependence.
WB1998 deduced a correlation between the G140L sensitivity measurements and the
temperature recorded at the charge amplifier (OM1CAT in the.spt file) of the FUVMAMA detector. With additional measurements in hand, that relationship was updated
slightly in B1999. The reported effect is a change in sensitivity of -0.25% per degree (˚C)
change in OM1CAT.
We perform a similar analysis of the other FUV-MAMA first order data, G140M. We
find that for G140M(1150-1190Å) the variation is -0.42%/˚C ±0.08 (rms=0.33) and for
G140M(1542-1592Å) it is -0.22 ±0.09 (rms=0.40). We combine the G140M data by normalizing both datasets to 1 at a temperature which they have in common, 34 ˚C. This
yields a fit of -0.31%/˚C ±0.06 (rms=0.39), in good agreement with the G140L analysis.
We use the -0.25%/˚C, G140L result, to remove temperature dependent trends from
both the FUV-MAMA L and M mode data, normalizing each observation’s sensitivity to a
reference temperature of 36 ˚C, i.e.:
FUV-MAMA Relative Sensitivity = Relative Sensitivity + 0.0025 *(OM1CAT -36.0)
3b. FUV-MAMA: Correction for +3˝ to -3˝ repositioning of G140 L, and M, Spectra
Presumably due to lack of a low order flatfield calibration [the extraction traces were
checked and found to be nominal], there is a small but significant change in sensitivity at
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Instrument Science Report STIS 2000-03
the new default position of the first-order spectra on the FUV-MAMA detector. We
remove that difference to arrive at a uniform set of data covering the epochs before and
after the change. For G140L data, we use the correction derived and described in the
“Time Correlations” section in B1999.
For each set of G140M observations, CENWAVE 1173 and 1567, we perform a derivation similar to that for the G140L. After extracting the net counts spectrum from each
reduced, X1D, observation, we sum those counts that are within the broadband wavelength ranges listed in column 4 of TABLE 1. Using just the data taken from the +3˝
position, a linear fit is made of the trend of those total net counts versus time. That fit is
then used to normalize all, both +3˝ and -3˝, datapoints to the date of the earliest data
point. With the time variation removed, a ratio spectrum is produced by dividing the average of the +3˝ by the average of the -3˝ spectra. That measure of the difference in
sensitivity at the two detector positions is presented in FIGURES 1 and 2. The “noisy”
line in each figure is the ratio spectrum while the smooth line is a cubic spline fit (5
splines) to the ratio. We apply these corrections in wavelength space and plot those wavelengths along the x-axis. However, in assuming that these are flatfield variations, it is
appropriate to consider the x-axis to be related to the pixel to pixel column position across
the detector.
The broadband average of the ratio spectrum is used as correction factor to normalize
all -3˝ datapoints to the +3˝ values. That correction is applied to the net count, X1D, data
prior to the following analyses of trends in time.
Figure 1: Ratio of the G140M(λc 1173Å) average at +3˝ to average at -3˝ after temperature and time corrections to sensitivity.
4
Instrument Science Report STIS 2000-03
Figure 2: Ratio of the G140M(λc 1567Å) average at +3˝ to average at -3˝ after temperature and time corrections to sensitivity.
3c.Sensitivity Variations with Time
After the G140L data are normalized to 36 ˚C and all FUV-MAMA data are normalized to a +3˝ position on the detector, we examine each of the monitoring modes for any
variation in sensitivity with time. For each observation the total of the net counts in the
wavelength regions given in Table 1 is divided by the value from the first, earliest observation in that mode. A linear fit, using iraf.stsdas.ttools.tlinear, is made of the trend of these
relative sensitivities per year of time. Following the deduction of B1999 we split the
G230L, NUV-MAMA, spectra into two epochs, before and after ~1998.7, and apply separate linear fits to each epoch. To further examine this “two-epoch” trending we perform a
similar analysis of the other modes whose spectra are within the wavelength range of the
G230L, i.e, G230M from the NUV-MAMA and G230MB and G230LB from the CCD.
Figures 4 through 22 present the relative sensitivity vs. time for each monitoring
mode, plus the linear fits to those points. The slope, i.e. per cent per year change in sensitivity, and 1 σ uncertainty in the fits is given at the bottom of each figure. The 1 σ rms(%)
of the data residuals from their linear fit values is given by the SIGMA value also at the
bottom of each figure. A summary of those values for each mode is contained in TABLE
1.
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Instrument Science Report STIS 2000-03
Table 1. Analysis Parameters and Results of Linear Fits to Sensitivity vs. Time.
Epoch
(All,
unless
noted)
Extracted
Wave_range
(Å)
%/yr
±
Sigma (%)
(rms of fit
residuals)
G140L
1300-1500
-1.36
0.15
0.53
5
G140Mλ1
1150-1190
-3.51
0.48
0.69
6
G140Mλ2
1542-1592
-2.19
0.24
0.49
7
G230L
2200-2600
-0.12
0.16
0.55
8
G230L
<1998.7
2200-2600
1.49
0.37
0.36
8
G230L
>1998.7
2200-2600
-1.36
0.15
0.20
9
G230M
2775-2860
0.02
0.16
0.33
10
G230M
<1998.7
2775-2860
1.13
0.22
0.11
10
G230M
>1998.7
2775-2860
-0.58
0.18
0.18
11
G230LB
2000-3000
-0.14
0.16
0.39
12
G230LB
<1998.7
2000-3000
0.72
0.21
0.16
12
G230LB
>1998.7
2000-3000
-1.25
0.31
0.24
13
G230MBλ1
1920-2070
-0.11
0.43
0.70
14
G230MBλ1
<1998.7
1920-2070
0.84
0.64
0.38
14
G230MBλ1
>1998.7
1920-2070
-3.06
0.83
0.27
15
G230MBλ2
2340-2490
-0.67
0.27
0.45
16
G230MBλ2
<1998.7
2340-2490
0.35
0.53
0.32
16
G230MBλ2
>1998.7
2340-2490
-1.91
0.01
0.01
17
G430L
3100-5500
-0.26
0.26
0.63
18
G430Mλ1
3050-3300
-0.87
0.11
0.18
19
G430Mλ2
4060-4320
-1.07
0.08
0.12
20
G430Mλ2
4060-4320
-1.31
0.12
0.12
21
G750L
5600-7000
0.07
0.16
0.39
22
G750M
7000-7500
-1.21
0.13
0.21
Figure #
Mode
4
GAIN 4
A graphical summary of TABLE 1 is provided by Figure 3. For each mode we plot the
derived yearly change in sensitivities vs. the central wavelength of the grating. The diamonds are the M mode data and the x’s are the L mode. The vertical error bars are the 1 σ
uncertainties in the sensitivity trends. The horizontal “error bars” are the range in wavelength extracted for analysis of the given mode. The numbers at the left of each data point
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Instrument Science Report STIS 2000-03
are the index (figure) number for that mode as provided in the first column of Table 1. The
cluster at ~2500Å of non-negative sensitivity trends are the pre-1998.7 two-epoch
measures.
Figure 3: Summary of Rates of Change in Sensitivity per Instrument Mode and Wavelength.
4. Discussion of Sensitivity vs. Time.
The current results are in general agreement with previous reports; however, additional
trends are suggested, particularly by extension of the two-epoch analyses of B1999 to
modes other than G230L, as well as by comparing overall trends separately in the L and in
the M modes.
4a. Present results vs. previously reported trends.
The rates of change in sensitivity with time (%/yr column in Table 1) are consistent
with those found for matching instrument modes (i.e., the L modes) presented in B1999
and WB1998. The values are within approximately 1 σ with respect to B1999. We make
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Instrument Science Report STIS 2000-03
that comparison by averaging the fit values for those wavelength bins in B1999 which
cover the same wavelength range as the ‘single bin’ passbands of the current analyses.
The M mode time variations in Table 1 are also consistent with those from similar wavelength regions in the L mode fits of B1999. However, that consistency generally requires
allowing 2 σ variations in the fits.
In one particular mode, G750M (7000-7500Å), the change in sensitivity versus time is
6 σ different from a similar passband in the G750L analysis in B1999 ( -1.21 ±0.13 vs. 0.28 ±0.08).
4b. Two-epoch analysis of modes covering 1900-3000Å.
The G230L (MAMA) mode was shown by B1999 to exhibit a bimodal time variation
in sensitivity. It increases in sensitivity prior to ~1998.7 and decreases thereafter. This
two-epoch variation was suggested by the apparent non-random scatter from a single
epoch linear fit and by the improvement in the fit-residuals when splitting the fit into two
epochs (see Figs. 7 and 8). We expand this two-epoch analysis to all modes with wavelength coverage within that of the G230L.
While a single linear fit to all of the G230M (MAMA) data (Fig. 9) indicates, with relatively large uncertainty, no variation with time, two-epoch fits (Fig. 10) yield slopes
significant to 3 σ and reduce the fit residuals by a factor of 2. The suggested variations in
sensitivity agree with the equivalent passband in B1999’s G230L analysis, within ~1 σ
before ~1998.7 and ~2 σ after that date.
Similarly, two-epoch fits to G230LB(2000-3000Å) (CCD), and to the two separate
central wavelength datasets of G230MB (CCD) yield significant reductions to the fit
uncertainties and residuals (compare Figs. 11 through 16). [Though this report includes
only 3 post-1998.7 datapoints for G230MB, quicklook analyses (Stys and Walborn, private communication, 19Jul00) using two additional recent proposal 8418 spectra find the
post-1998.7 trend continuing in both G230MB modes. If additional data validate these
G230MB trends, these two modes exhibit the largest rate of decline in sensitivity, at ~ -2
to -3 %/yr.]
Overall the data in all MAMA and CCD modes covering 1900-3000Å suggest a trend
in sensitivity that is increasing prior to ~1998.7 and which is decreasing thereafter. The
data from modes redward of 3000Å, G430<*> and G750<*>, suggest a single linear trend
over the entire monitoring period.
These trends suggest that the changes affecting G230L are not particular to that mode
or detector, but, instead, are more generic processes which are wavelength dependent and
strongest in the 2000-3000Å range.
4c. M modes versus L modes.
Except for G230M, our linear fit measures of the rates of loss in sensitivity for all M
modes are greater than those of the ‘comparable’ (same detector and equivalent central
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Instrument Science Report STIS 2000-03
wavelengths) L modes. This can be seen in comparisons using the %/year change in sensitivity values in Table 1, Figure 3, and the averages of the equivalent passbands in the L
modes of the B1999 analyses. However, given the uncertainties of the fits, the actual significance of these M vs. L mode differences varies from <1 σ to >5 σ. For most modes
the differences are marginal (<3 σ). But, the difference in rates of change are more significant, 3 σ and >5 σ respectively, for the longer wavelength(4060-4320A) G430M vs.
G430L, and the G750M vs. G750L.
It is expected that any sensitivity changes may vary with wavelength. It is very difficult to ascribe any possibility of an overall M vs. L mode difference to a single effect
because of the differences in the optical elements in the light path of each mode. However,
for the CCD modes, where the difference in rate of change of sensitivity is most significant, the only difference in the optical elements (besides the gratings) is that the L modes
use different order sorting filters than the M modes.
Further monitoring and a more detailed, wavelength dependent, analysis should be the
next step in tracing the source of these differences. From the present data and analyses, the
most definite conclusions are that the MAMA M modes track the corresponding L mode
wavelength regions, while the CCD G430M and G750M modes exhibit significantly
greater changes than any corresponding L mode regions.
4d. Gain 4 vs. Gain 1.
Figure 23 shows the ratio of each of the 5 pairs of gain 1,gain 4 G430M(4060-4320)
measurements covered by this report. The error bars are the propagated poissonian errors
and a linear fit is overplotted. There was no significant change within the time period covered. The mean value is 4.039 ±0.006 (WB1998 found 4.034 ±0.010).
4e. Repeatability
If one obtains spectra in the same observing mode, with comparably high signal, the
‘SIGMA’ values in Table 1 represent the 1 σ uncertainty, or repeatability, in the absolute
flux assignments. That is, assuming that the temperature and/or time variations in sensitivity are corrected.
5. Summary
We have added detailed M mode trends to the characterization of STIS sensitivity
trends. While the known trends are generally confirmed we show the need to expand the
G230L ‘two-epoch’ analysis to other modes. In particular, we found that:
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Instrument Science Report STIS 2000-03
•
Only the G750L shows no significant variation in sensitivity. For the G430L, our average over a broad band, 3100-5500Å, is within 1σ of the B1999 result of -0.56%
±0.16%. Most other modes show evidence for an ~1%/yr decline except for G140M
being ~2.5%/yr and G140L being ~1.4%/yr (broad band average, but tracking the
larger declines at the wavelengths corresponding to the two G140M modes that are
monitored) and G230L (after ~1999.7) also declining at ~1.4%/yr . Also, if confirmed
by additional data, the two monitored G230MB modes are declining at ~ 2 to 3%/yr
after ~ 1998.7
•
A bimodal, before and after ~1998.7, trend evident in the NUV-MAMA G230M is
similar to that of the G230L. Similar trends are also evident in the CCD G230LB and
the two G230MB monitoring modes.
•
The rate of decline in sensitivity is systematically greater in some of the M modes
(G430M(4060-4320) and G750M) relative to the corresponding L modes.
•
The temperature dependence of the sensitivity in the G140M modes is consistent with
the 0.25%/˚C correlation in the G140L mode.
•
The “relative gain”, gain1/gain4, of the CCD has not changed significantly. Between
1998.3 and 1999.7 the mean of this ratio was 4.039 ±0.006.
•
The corrections needed to normalize data taken at +3” versus -3” from the center line
of the FUV-MAMA detector indicate that the lack of low order flatfielding leaves
residual sensitivity variation of as much as 8%, peak to peak, between the two positions.
6. Recommendations
•
Pipeline corrections should be implemented to account for the FUV-MAMA variation
of 0.25%/˚C in both G140L and G140M modes. Future derivations of that relation
should include both sets of G140M data.
•
The wavelength-dependent correction for the time variations in G140L, G230L, and
G430L (a null correction to G750L) recommended in B1999 should be implemented
in the pipeline.
•
Our current suite of IRAF-based analysis software should be enhanced to provide
wavelength dependent analysis of each mode.
•
When a low-order flatfield is available for the FUV-MAMA, the +3˝/-3˝ correction
should be removed from these monitoring analyses (if the two prove to be consistent).
Until then, that correction should be derived using the iterative procedure described in
B1999.
•
When a ‘two-epoch’ wavelength-dependent analysis of the G230LB has been completed, a pipeline correction for time variation in that mode should be implemented in
the same manner as the G230L.
•
The narrow passbands of the G140M, G230M, and G230MB modes should not
require wavelength-dependent corrections for their time variation; thus, the correction
algorithm in the pipeline (two-epoch for the latter two modes) should easily allow for a
correction that is constant in wavelength for these modes.
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Instrument Science Report STIS 2000-03
•
With the additional data in hand as of June 2000, a wavelength-dependent comparison
of the FUV-MAMA and NUV-MAMA M modes to the comparable L modes should be
adequate to confirm that there is no significant difference in the time variations
between those particular M and L modes. If that is confirmed, the L modes for those
detectors should be used to derive the pipeline correction for wavelength-dependent
time variation in the passbands of all of the G140M and G230M modes (two-epoch
correction for G230M). It is preferable to use the L modes because they receive more
frequent monitoring and will better track changes in time; their larger number of measurements yield better number statistics; and because we monitor only a few of the
wavelength settings for the M modes, thus, corrections for only those few would be
available. The monitored M modes should be used to periodically confirm that they are
being tracked by the L modes.
•
We do not recommend similar pipeline corrections for the CCD M modes. The CCD L
modes have not been shown to track changes in the wavelength regions of the corresponding M modes and there are only a few of the M modes being monitored and thus
potentially correctable. However, the sensitivity calibration files currently being used
for the CCD M modes should be updated.
•
The probable two-epoch time trends for the G230MB modes leave too few data points
to adequately define either the pre- or post-1998.7 trends. Sufficient data points to
establish reliable post-1998.7 trend coefficients should be in hand by summer 2001.
Then, given the other CCD L modes which do not track the M mode variations, a
review should be made of whether the G230MB mode time variation is significantly
different than the G230LB.
•
Unlike the other M modes, the wider passbands of the CCD G430M and G750M
modes may warrant a wavelength-dependent correction for time variations. Since the
G430L mode was not shown to track the time variations in the G430M(4060-4320)
mode, we recommend that all G430M time corrections be derived independently using
the G430M data in hand as of June, 2000. The independence of the G430M and the
equivalent G430L passbands should be revisited in summer 2001. Similarly, a G750M
time correction should be derived from a wavelength-dependent analysis of the
G750M data in hand at the date of this ISR. However, the lack of data at most M mode
settings introduces a basic uncertainty about possible differences among them.
•
The analysis software should be modified to project all sensitivity trends back to the
same date for all modes, e.g. 1997.38 as recommended by B1999, in order to more
easily assess the total sensitivity changes and compare them mode to mode.
•
The larger scatter in the CCD L mode measurements relative to the M modes (Figs.1822) should be investigated.
•
The echelle mode data should be investigated. In particular, the medium resolution
echelle, EM modes, provide complete spatial and wavelength coverage of the MAMA
detectors, which may help resolve ambiguities remaining from the use of the firstorder data.
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Instrument Science Report STIS 2000-03
7. REFERENCES
Walborn, N., & Bohlin, R. 1998, Instrument Science Report, STIS 98-27, (Baltimore:STScI). (WB1998).
Bohlin, R. 1999, Instrument Science Report, STIS 99-07, (Baltimore:STScI). (B1999).
Thanks to Susan Rose for the FRAMEmaking!
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Instrument Science Report STIS 2000-03
Figure 4: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 5:
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Instrument Science Report STIS 2000-03
Figure 6: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 7:
14
Instrument Science Report STIS 2000-03
Figure 8: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 9:
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Instrument Science Report STIS 2000-03
Figure 10: Linear fit to Relative Sensitivity vs. Time. With the%/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 11:
16
Instrument Science Report STIS 2000-03
Figure 12: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 13:
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Instrument Science Report STIS 2000-03
Figure 14: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 15:
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Instrument Science Report STIS 2000-03
Figure 16: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 17:
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Instrument Science Report STIS 2000-03
Figure 18: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 19:
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Instrument Science Report STIS 2000-03
Figure 20: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 21:
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Instrument Science Report STIS 2000-03
Figure 22: Linear fit to Relative Sensitivity vs. Time. With the %/yr slope of the fit, the 1 σ uncertainty in
the fit and the 1 σ rms scatter about the fit.
Figure 23: “Gain Ratio”: G430M(4060-4320) GAIN 1 / G430M(4060-4320) GAIN 4
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Instrument Science Report STIS 2000-03
APPENDIX 1:OBSERVATION LOG for the STIS Sensitivity Monitoring Program
(through December 1999).
Observation
Mode
CenWave
Date
Time (UT)
Propid
Exptime (sec)
G140L (CenWave =1425)
o45901010
G140L
1425
08/12/97
9:18:10
7673
180
o45910010
G140L
1425
09/16/97
21:11:23
7673
180
o45911010
G140L
1425
10/06/97
13:36:39
7673
180
o45912010
G140L
1425
11/17/97
17:23:40
7673
180
o45913010
G140L
1425
12/19/97
23:54:46
7673
180
o45914010
G140L
1425
01/09/98
15:03:40
7673
216
o45915010
G140L
1425
02/12/98
14:55:32
7673
189
*o45916010
G140L
1425
03/11/98
9:21:19
7673
failed
o45917010
G140L
1425
04/12/98
17:57:12
7673
204
o45940010
G140L
1425
05/07/98
2:51:18
7673
204
*o45941010
G140L
1425
05/27/98
19:16:27
7673
failed
o45942010
G140L
1425
07/04/98
18:54:31
7673
204
o45943010
G140L
1425
08/05/98
7:38:58
7673
204
o45944010
G140L
1425
09/23/98
8:02:51
7673
204
o45945010
G140L
1425
10/14/98
22:40:39
7673
204
o45946010
G140L
1425
11/04/98
6:35:51
7673
204
o45947010
G140L
1425
12/14/98
14:51:39
7673
204
o45948010
G140L
1425
01/03/99
8:36:14
7673
204
o45949010
G140L
1425
02/11/99
12:54:13
7673
204
o45950010
G140L
1425
03/08/99
16:55:02
7673
204
o45951010
G140L
1425
04/11/99
5:52:14
7673
204
o45952010
G140L
1425
05/12/99
18:15:58
7673
204
o45953010
G140L
1425
06/03/99
2:08:16
7673
204
o5jj01010
G140L
1425
07/03/99
8:44:21
8424
201
o5jj02010
G140L
1425
08/03/99
0:32:16
8424
204
o5jj03010
G140L
1425
09/18/99
0:30:05
8424
201
o5jj99010
G140L
1425
10/01/99
18:14:28
8424
204
**o5jj99030
G140L
1425
10/01/99
18:35:41
8424
204
o5jj05010
G140L
1425
11/09/99
14:04:08
8424
201
23
Instrument Science Report STIS 2000-03
Observation
Mode
CenWave
Date
Time (UT)
Propid
Exptime (sec)
G140M (CenWave=1173)
o45921020
G140M
1173
05/17/98
18:48:20
7673
354
o45922020
G140M
1173
07/05/98
17:25:21
7673
354
o45923020
G140M
1173
09/13/98
12:50:06
7673
354
o45924020
G140M
1173
11/07/98
3:57:37
7673
354
o45925020
G140M
1173
01/16/99
0:38:55
7673
354
o45926020
G140M
1173
03/08/99
15:01:44
7673
354
o45927020
G140M
1173
05/14/99
15:25:53
7673
295
o5jj15020
G140M
1173
07/01/99
13:10:20
8424
210
o5jj16020
G140M
1173
09/11/99
20:10:46
8424
210
o5jj17020
G140M
1173
11/08/99
23:41:21
8424
210
G140M (CenWave=1567)
o45902010
G140M
1567
09/19/97
18:13:12
7673
360
o45920010
G140M
1567
01/09/98
9:48:28
7673
360
o45921010
G140M
1567
05/17/98
18:35:17
7673
334
o45922010
G140M
1567
07/05/98
17:12:07
7673
354
o45923010
G140M
1567
09/13/98
12:36:52
7673
354
o45924010
G140M
1567
11/07/98
3:44:23
7673
354
o45925010
G140M
1567
01/16/99
0:25:46
7673
354
o45926010
G140M
1567
03/08/99
14:48:35
7673
354
o45927010
G140M
1567
05/14/99
15:12:53
7673
295
o5jj15010
G140M
1567
07/01/99
12:57:15
8424
300
o5jj16010
G140M
1567
09/11/99
19:57:41
8424
300
o5jj17010
G140M
1567
11/08/99
23:28:16
8424
300
G230L (CenWave=2376)
o45901020
G230L
2376
08/12/97
10:14:48
7673
184
o45910020
G230L
2376
09/16/97
21:21:49
7673
184
o45911020
G230L
2376
10/06/97
13:47:05
7673
184
o45912020
G230L
2376
11/17/97
17:34:06
7673
184
o45913020
G230L
2376
12/20/97
0:05:12
7673
184
o45914020
G230L
2376
01/09/98
15:14:20
7673
216
o45915020
G230L
2376
02/12/98
15:05:45
7673
216
24
Instrument Science Report STIS 2000-03
Observation
Mode
CenWave
Date
Time (UT)
Propid
Exptime (sec)
*o45916020
G230L
2376
03/11/98
9:31:32
7673
failed
o45917020
G230L
2376
04/12/98
18:07:40
7673
204
o45940020
G230L
2376
05/07/98
3:01:46
7673
204
*o45941020
G230L
2376
05/27/98
19:26:46
7673
failed
o45942020
G230L
2376
07/04/98
19:04:50
7673
204
o45943020
G230L
2376
08/05/98
7:49:17
7673
204
o45944020
G230L
2376
09/23/98
8:13:10
7673
204
o45945020
G230L
2376
10/14/98
22:50:58
7673
204
o45946020
G230L
2376
11/04/98
6:46:10
7673
204
o45947020
G230L
2376
12/14/98
15:01:58
7673
204
o45948020
G230L
2376
01/03/99
8:46:33
7673
204
o45949020
G230L
2376
02/11/99
13:04:32
7673
204
o45950020
G230L
2376
03/08/99
17:05:21
7673
204
o45951020
G230L
2376
04/11/99
6:02:33
7673
204
o45952020
G230L
2376
05/12/99
18:26:17
7673
204
o45953020
G230L
2376
06/03/99
2:18:35
7673
204
o5jj01020
G230L
2376
07/03/99
8:54:37
8424
204
o5jj02020
G230L
2376
08/03/99
0:42:35
8424
204
o5jj03020
G230L
2376
09/18/99
0:40:21
8424
204
o5jj99020
G230L
2376
10/01/99
18:24:47
8424
204
o5jj05020
G230L
2376
11/09/99
14:14:24
8424
204
G230M (CenWave=2818)
o45902020
G230M
2818
09/19/97
18:27:32
7673
576
o45920020
G230M
2818
01/09/98
10:02:27
7673
576
o45921030
G230M
2818
05/17/98
19:02:08
7673
570
o45922030
G230M
2818
07/05/98
17:39:00
7673
570
o45923030
G230M
2818
09/13/98
13:03:45
7673
570
o45924030
G230M
2818
11/07/98
4:11:16
7673
570
o45925030
G230M
2818
01/16/99
0:52:34
7673
570
o45926030
G230M
2818
03/08/99
15:15:23
7673
570
o45927030
G230M
2818
05/14/99
15:38:33
7673
475
o5jj15030
G230M
2818
07/01/99
13:21:35
8424
480
25
Instrument Science Report STIS 2000-03
Observation
Mode
CenWave
Date
Time (UT)
Propid
Exptime (sec)
o5jj16030
G230M
2818
09/11/99
20:22:01
8424
480
o5jj17030
G230M
2818
11/08/99
23:52:36
8424
480
G230LB (CenWave=2375)
o45a01010
G230LB
2375
08/03/97
0:31:02
7672
144
o45a03010
G230LB
2375
10/01/97
5:49:13
7672
144
o45a04010
G230LB
2375
12/01/97
1:43:39
7672
144
o45a05010
G230LB
2375
02/04/98
7:59:36
7672
144
o45a06010
G230LB
2375
04/01/98
11:00:23
7672
144
o45a12010
G230LB
2375
05/31/98
16:13:52
7672
172
o45a13010
G230LB
2375
07/31/98
21:27:24
7672
172
o45a14010
G230LB
2375
10/12/98
12:29:56
7672
172
o45a15010
G230LB
2375
12/06/98
22:46:56
7672
172
o45a16010
G230LB
2375
02/07/99
0:36:26
7672
172
o45a17010
G230LB
2375
04/03/99
15:30:29
7672
172
o45a18010
G230LB
2375
06/03/99
13:29:36
7672
172
o5ig01010
G230LB
2375
08/01/99
1:16:42
8418
172
o5ig02010
G230LB
2375
10/03/99
2:14:59
8418
172
G230MB (CenWave=1995)
o45a02010
G230MB
1995
09/01/97
11:56:05
7672
240
o45a07010
G230MB
1995
01/01/98
8:37:29
7672
240
o45a08010
G230MB
1995
04/18/98
0:49:06
7672
240
o45a09010
G230MB
1995
08/24/98
15:39:43
7672
240
o45a10010
G230MB
1995
01/13/99
6:23:58
7672
240
o45a11010
G230MB
1995
05/01/99
2:06:28
7672
240
o5ig08010
G230MB
1995
09/11/99
13:31:28
8418
240
G230MB (CenWave=2416)
o45a02020
G230MB
2416
09/01/97
12:06:20
7672
180
o45a07020
G230MB
2416
01/01/98
8:47:44
7672
180
o45a08020
G230MB
2416
04/18/98
0:59:21
7672
180
o45a09020
G230MB
2416
08/24/98
15:49:58
7672
180
o45a10020
G230MB
2416
01/13/99
6:34:19
7672
180
o45a11020
G230MB
2416
05/01/99
2:16:49
7672
180
o5ig08020
G230MB
2416
09/11/99
13:41:49
8418
180
26
Instrument Science Report STIS 2000-03
Observation
Mode
CenWave
Date
Time (UT)
Propid
Exptime (sec)
G430L (CenWave=4300)
o45a01020
G430L
4300
08/03/97
0:39:41
7672
144
o45a03020
G430L
4300
10/01/97
5:57:52
7672
144
o45a04020
G430L
4300
12/01/97
1:52:18
7672
144
o45a05020
G430L
4300
02/04/98
8:08:15
7672
144
o45a06020
G430L
4300
04/01/98
11:09:02
7672
144
o45a12020
G430L
4300
05/31/98
16:23:01
7672
172
o45a13020
G430L
4300
07/31/98
21:36:33
7672
172
o45a14020
G430L
4300
10/12/98
12:39:05
7672
172
o45a15020
G430L
4300
12/06/98
22:56:11
7672
172
o45a16020
G430L
4300
02/07/99
0:45:41
7672
172
o45a17020
G430L
4300
04/03/99
15:39:44
7672
172
o45a18020
G430L
4300
06/03/99
13:38:51
7672
172
o5ig01020
G430L
4300
08/01/99
1:25:57
8418
172
o5ig02020
G430L
4300
10/03/99
2:24:14
8418
172
G430M (CenWave=3165)
o45a02030
G430M
3165
09/01/97
12:16:05
7672
120
o45a07030
G430M
3165
01/01/98
8:57:29
7672
120
o45a08050
G430M
3165
04/18/98
1:20:29
7672
120
o45a09050
G430M
3165
08/24/98
16:11:06
7672
120
o45a10050
G430M
3165
01/13/99
6:55:39
7672
120
o45a11050
G430M
3165
05/01/99
2:38:09
7672
120
o5ig08030
G430M
3165
09/11/99
13:51:40
8418
120
G430M (CenWave=4194, GAIN=1)
o45a02040
G430M
4194
09/01/97
12:24:00
7672
120
o45a07040
G430M
4194
01/01/98
9:05:24
7672
120
o45a08040
G430M
4194
04/18/98
1:12:34
7672
120
o45a09040
G430M
4194
08/24/98
16:03:11
7672
120
o45a10040
G430M
4194
01/13/99
6:47:38
7672
120
o45a11040
G430M
4194
05/01/99
2:30:08
7672
120
o5ig08040
G430M
4194
09/11/99
13:59:41
8418
120
27
Instrument Science Report STIS 2000-03
Observation
Mode
CenWave
Date
Time (UT)
Propid
Exptime (sec)
G430M (CenWave=4194, GAIN=4)
o45a08030
G430M
4194
04/18/98
1:09:06
7672
120
o45a09030
G430M
4194
08/24/98
15:59:43
7672
120
o45a10030
G430M
4194
01/13/99
6:44:10
7672
120
o45a11030
G430M
4194
05/01/99
2:26:40
7672
120
o5ig08050
G430M
4194
09/11/99
14:03:09
8418
120
G750L (CenWave=7751)
o45a01030
G750L
7751
08/03/97
0:48:20
7672
360
o45a03030
G750L
7751
10/01/97
6:06:31
7672
360
o45a04030
G750L
7751
12/01/97
2:00:57
7672
360
o45a05030
G750L
7751
02/04/98
8:16:54
7672
360
o45a06030
G750L
7751
04/01/98
11:17:41
7672
360
o45a12030
G750L
7751
05/31/98
16:32:10
7672
432
o45a13030
G750L
7751
07/31/98
21:45:42
7672
432
o45a14030
G750L
7751
10/12/98
12:48:14
7672
432
o45a15030
G750L
7751
12/06/98
23:05:26
7672
432
o45a16030
G750L
7751
02/07/99
0:54:56
7672
432
o45a17030
G750L
7751
04/03/99
15:48:59
7672
432
o45a18030
G750L
7751
06/03/99
13:48:06
7672
432
o5ig01030
G750L
7751
08/01/99
1:35:12
8418
432
o5ig02030
G750L
7751
10/03/99
2:33:29
8418
432
G750M (CenWave=7283)
o45a02050
G750M
7283
09/01/97
12:32:45
7672
120
o45a07050
G750M
7283
01/01/98
9:14:09
7672
120
o45a08060
G750M
7283
04/18/98
1:29:14
7672
120
o45a09060
G750M
7283
08/24/98
16:19:51
7672
120
o45a10060
G750M
7283
01/13/99
7:04:30
7672
120
o45a11060
G750M
7283
05/01/99
2:47:00
7672
120
o5ig08060
G750M
7283
09/11/99
14:12:00
8418
120
* Data not usable due to on-orbit problems.
** o5jj99030 taken at +3" position.
28