STIS Instrument Science Report 96-021
Limiting Magnitude Tables for STIS
Bright Object Protection (BOP)
Mark Clampin and E. Kinney
10 May 1996
ABSTRACT
In this ISR we present tables of global and local Bright Object Protection (BOP) count
rate limits, as a function of STIS observing configuration, for the STIS Instrument Handbook section on MAMA detectors.
1. Introduction
The STIS Multianode-Microchannel Arrays (MAMA) are photon counting detectors and,
therefore, susceptible to damage by over-illumination. In order to prevent catastrophic loss
of the MAMA detectors, there are onboard monitors designed to prevent the violation of
local and global count rate limits. These monitors are described in detail in the STIS ISR
on Bright Object Protection. In order to ensure that the monitors are tripped infrequently,
all STIS proposals will be subject to screening for bright objects which might give rise to
excessive count rate levels.
The purpose of this ISR is to summarize the current screening limits for bright object protection, for publication in the STIS Instrument Handbook.
2. Simulation sources
The sources used in the calculation of the bright object limits for STIS have been taken
from the Bruzual-Persson-Gunn-Stryker (BPGS) Spectrophotometry Atlas. This atlas is
an extension of the Gunn-Stryker optical atlas and has been extended into the UV, making
it suitable for STIS simulations. In Table 1 we present the BPGS template spectra used in
the STIS observing simulations. The spectral types selected provide fairly uniform coverage from O5 to M8. In addition, following the convention used in the FOS bright object
limit tables, we have included a T~50000 oK blackbody and a flat spectral source Fν, varying as ν-1.
1
Table 1. BPGS template spectra used in the STIS simulations, together with their logical
pathname within SYNPHOT.
Source
Type
Synphot filename
9 Sgr
O5
crgrid$bpgs/bpgs_1
BD 01 0935
B1V
crgrid$bpgs/bpgs_4
Iota Her
B3V
crgrid$bpgs/bpgs_8
HR 7174
B6V
crgrid$bpgs/bpgs_11
HD 189689
B9V
crgrid$bpgs/bpgs_13
HD 190849A
A1V
crgrid$bpgs/bpgs_17
HD 190849B
A3V
crgrid$bpgs/bpgs_19
HD 190192
A5V
crgrid$bpgs/bpgs_28
HD 508
A9IV
crgrid$bpgs/bpgs_88
Rho Cap
F2IV
crgrid$bpgs/bpgs_90
HD 181177
F4V
crgrid$bpgs/bpgs_31
BD +29 3891
F6V
crgrid$bpgs/bpgs_33
HD 155675
F8V
crgrid$bpgs/bpgs_38
HD 154760
G2V
crgrid$bpgs/bpgs_45
BD -02 4018
G6IV
crgrid$bpgs/bpgs_100
HD 56176
G7IV
crgrid$bpgs/bpgs_104
HD 7010
K0IV
crgrid$bpgs/bpgs_117
HD 154712
K4V
crgrid$bpgs/bpgs_57
BD +28 2457
K8V
crgrid$bpgs/bpgs_59
GL 49
M2V
crgrid$bpgs/bpgs_67
GL 109
M4V
crgrid$bpgs/bpgs_68
GL 15B
M6V
crgrid$bpgs/bpgs_69
Z Cyg
M8III
crgrid$bpgs/bpgs_163
50000o Blackbody
T=50,000o K
bb(50000)
Flat spectrum Fν where να-1
unit(100,photlam)
The SYNPHOT routine COUNTRATE was used to simulate observations in each STIS
observing configuration. COUNTRATE provides both a figure for the total count rate
(Totalcounts) and a tabular spectrum of the simulated STIS observation in units of counts/
May 1996
STIS Instrument Science Report 96-021
Page 2
sec. The current global and local count rate limits for which limiting magnitudes were to
be determined are summarized below in Table 2.
Table 2. Global and Local count rate limits for the MAMA detectors
Category
FUV MAMA
NUV MAMA
Global rate
Hardware monitor trigger level
300,000 counts/sec
300,000 counts/sec
Global rate
recommended maximum for linear science observations
200,000 counts/sec
200,000 counts/sec
Local rate
Hardware monitor trigger level
100 counts/sec/pixel
200 counts/sec/pixel
Local rate
recommended maximum for linear science observations
25 counts/sec/pixel
50 counts/sec/pixel
The global count rate limits were calculated by renormalizing each spectral type to a calculate Totalcounts for a V magnitude of 10 (STMAG). The global limits were then
calculated, using the currently defined hardware trigger and science screening limits,
shown below in Table 2, with the equations
Global LimitSTMAG = -2.5 x Log10 (Hardware_limit/Totalcounts) + 10
(1),
Global LimitSTMAG = -2.5 x Log10 (Screen_limit/Totalcounts) + 10
(2).
The local count rate limits for spectral modes were calculated by first screening the tabular
spectra for the highest count rate (Peakrate), and then applying the equations
Local LimitSTMAG = -2.5 x Log10 (Hardware_limit/(Psf_frac x Peakrate) + 10
(3),
Local LimitSTMAG = -2.5 x Log10 (Screen_limit/Psf_frac x Peakrate) + 10
(4),
where Psf_frac corresponds to the fraction of light that will fall in a single pixel row of the
spectrum (see Table 3). For FUV modes, the more conservative value of 0.195 was used in
these calculations.
Table 3. Fraction of light in brightest point spread function pixel
Wavelength (nm)
% light in central pixel
120
0.13
150
0.195
200
0.25
320
0.24
In the case of the point source imaging modes the local limits were calculated as
May 1996
STIS Instrument Science Report 96-021
Page 3
Local LimitSTMAG = -2.5 x Log10 (Hardware_limit/(Psf_frac x Totalcounts) + 10 (5),
Local LimitSTMAG = -2.5 x Log10 (Screen_limit/Psf_frac x Totalcounts) + 10
(6).
The diffuse imaging limits were calculated for each of the imaging filter configurations,
using a flat spectrum as the input, with the Totalcounts normalized to a square arcsec to
give
Local LimitSTMAG = -2.5 x Log10 (Hardware_limit/(Totalcounts/1600)) + 10
(7),
Local LimitSTMAG = -2.5 x Log10 (Screen_limit/(Totalcounts/1600)) + 10
(8).
The line limits were calculated again using the flat spectrum unit(1e-12,flam) as
input for COUNTRATE. The resulting count rates were then multiplied by the PSF fraction
and used to scale the line flux.
3. Global count rate limits (spectroscopic modes)
The global count rate limits for spectroscopic observing configurations were calculated
using the SYNPHOT routine COUNTRATE (further details of the calculations are given
in Appendix 1). A grid of count rates was calculated using the source spectra, summarized
in Table 1. For the gratings G140M, E140M, E140H, G230M, E230M, & E230H, the
count rate was taken as the scan setting which produced the high count rate. The resulting
grid of count rates were then used to determine the limiting magnitudes for:
1. Recommended limit for photometric accuracy of 200,000 counts/sec (Table 4).
2. Maximum allowed global count rate limits of 300,000 counts/sec (Table 5)
4. Local count rate limits (spectroscopic modes)
The local count rate limits for spectroscopic observing configurations were calculated
using the SYNPHOT routine COUNTRATE (further details of the calculations are given
in Appendix 1). A grid of count rates was calculated using the source spectra, summarized
in Table 1. A correction was applied for the predicted fraction of light in the central pixel.
The resulting count rates were then used to determine the limiting magnitudes for:
1. Recommended local count rate limit for photometric accuracy of
25 counts/sec (Table 6), or 50 counts/sec (Table 7)
2. Maximum allowed global count rate limits of 100 counts/sec. (Table 8) or 200
counts/sec. (Table 9)
5. Local count rate limits (point source imaging modes)
The local count rate limits for imaging modes were calculated using the SYNPHOT routine COUNTRATE (further details of the calculations are given in Appendix 1). A grid of
count rates was calculated, as a function of the STIS imaging configuration, for the source
May 1996
STIS Instrument Science Report 96-021
Page 4
spectra, summarized in Table 1. A correction was applied for the predicted fraction of
light in the central pixel (in the case of the Lα filter the value of 0.13 from Table 3 was
used). The resulting count rates were then used to determine the limiting magnitudes for:
1. Recommended local count rate limits (FUV imaging configuration) for photometric accuracy of 25 counts/sec/pixel (Table 10), or 50 counts/sec/pixel (Table 11)
2. Maximum allowed local count rate limits (FUV imaging configurations) for 100
counts/sec/pixel (Table 12), and 200 counts/sec/pixel (Table 13).
3. Recommended local count rate limits (NUV imaging configuration) for photometric accuracy of 25 counts/sec/pixel (Table 14), or 50 counts/sec/pixel (Table 15)
4. Maximum allowed local count rate limits (NUV imaging configurations) for 100
counts/sec/pixel (Table 16), and 200 counts/sec/pixel (Table 17).
6. Local count rate limits (diffuse imaging modes)
The local count rate limits for imaging modes were calculated using the SYNPHOT routine COUNTRATE. A grid of count rates was calculated, as a function of the STIS imaging
configuration, for a flat spectral source generated using the SYNPHOT command
UNIT(1e-12,flam). The resulting count rates were scaled to an area of 1 Sq. arcsec
then divided into 1.0x10-12 x Local_Rate to give:
1. Recommended local count rate limits for photometric accuracy in imaging diffuse
sources of 25 counts/sec/pixel and 50 counts/sec/pixel (Table 18)
2. Maximum allowed count rate limits for imaging diffuse sources of 100 counts/sec/
pixel and 200 counts/sec/pixel (Table 18).
7. Spectral line count rate limits
The local count rate limits, expressed as line fluxes, for spectroscopic modes were calculated using the SYNPHOT routine COUNTRATE. A grid of spectra were calculated, as a
function of the STIS spectroscopic configuration, for a flat spectral source generated using
the SYNPHOT command UNIT(1e-12,flam). The brightest pixel in each spectrum
was calculated using TSTAT, and scaled by the PSF fraction. The resulting count rates
were then divided into 1.0x10-12 x Local_Rate to give:
1. Maximum allowed count rate limit of 100 counts/sec/pixel for spectroscopy of
point sources with emission lines (Table 19)
2. Recommended local count rate limit of 50 counts/sec/pixel for spectroscopy of
point sources with emission lines (Table 19).
May 1996
STIS Instrument Science Report 96-021
Page 5
8. Open Issues
The following caveats apply to the numbers calculated in this report:
1. The prism numbers should be considered very uncertain, pending the delivery of a
dispersion solution for the long wavelength region (>280 nm). The concern here is
that the accumulation of flux, at wavelengths >280 nm, in a relatively small number of pixels. This may prove a problem for the local rate monitor.
2. The MAMA requirements for local rate limits were still under discussion at the
time of writing this document.
3. In order to maintain manageable tables, and the a degree of conservatism, slit
losses have not been considered in calculating the limits.
4. Once thermal vacuum data is available, and improved numbers are measured for
the fraction of light which is seen in the brightest pixel or strip of spectrum, the
tables should be revised.
5. In the FUV imaging and spectroscopic modes, abrupt changes in limiting magnitude are seen in sources ranging from A type to F spectral types. These changes are
a result of the relatively low efficiency of the long wavelength region of the STIS
FUV sensitivity curve, combined with the fact that these stars have hardly any flux
over the more sensitive short wavelength region of the STIS FUV passband. Consequently, small variations in the short wavelength spectrum from star to star produce significant changes in the calculated limiting magnitudes. This issue will
need to be addressed in the development of a bright object screening program.
May 1996
STIS Instrument Science Report 96-021
Page 6
Table 4. Global count rate STMAG limits for 200,000 counts/sec
Sp type
G140L
G140M
E140M
E140H
G230L
G230M
E230M
E230H
Prism
O5V
12.0
9.5
10.2
9.3
11.8
9.9
10.5
8.7
8.1
B1V
11.4
8.9
9.7
8.9
11.3
9.4
10.0
9.1
7.7
B3V
10.5
7.9
8.7
7.9
10.6
8.7
9.3
7.3
6.9
B6V
9.4
6.7
7.7
6.4
9.8
8.0
8.5
6.6
6.1
B9V
8.7
6.1
7.0
6.3
9.5
7.7
8.2
7.3
5.8
A1V
7.3
4.7
5.7
5.0
8.9
7.1
7.6
5.6
5.1
A3V
6.0
3.0
4.3
3.4
8.4
6.7
7.1
6.1
4.6
A5V
2.9
0.3
0.4
0.1
7.8
6.1
6.5
5.5
4.0
A9IV
2.7
0.1
0.2
-0.1
7.7
6.0
6.3
5.3
3.8
F2V
-0.4
7.1
5.6
5.7
4.7
3.2
F4V
-0.5
7.0
5.5
5.6
4.6
3.1
F6V
-0.5
7.0
5.4
5.6
4.5
3.1
F8V
-0.4
6.8
5.1
5.2
4.1
2.8
G2V
6.5
4.9
5.0
3.8
2.5
G5IV
5.9
4.3
4.3
3.1
1.8
G7IV
4.9
3.0
3.0
1.4
0.6
K0IV
4.5
2.6
2.7
1.1
0.3
K4V
4.2
2.2
2.2
0.7
-0.1
K8V
4.1
1.9
2.1
0.5
-0.3
M2V
3.6
1.9
1.9
0.8
-0.5
M4V
3.4
1.7
1.8
0.6
-0.7
M6V
2.9
1.3
1.3
0.1
-1.2
M8III
1.8
0.1
0.1
-1.1
-2.3
T~50000oK
11.9
9.3
10.1
9.2
11.7
9.8
10.4
9.4
8.1
ν-1
8.4
7.7
6.7
6.6
9.5
8.6
8.2
7.7
9.5
May 1996
STIS Instrument Science Report 96-021
Page 7
Table 5. Global count rate STMAG limits for 300,000 counts/sec
Sp type
G140L
G140M
E140M
E140H
G230L
G230M
E230M
E230H
Prism
O5V
11.6
9.0
9.8
8.9
11.4
9.4
10.1
8.2
7.7
B1V
11.0
8.5
9.2
8.4
10.9
9.0
9.6
8.6
7.2
B3V
10.0
7.5
8.3
7.5
10.1
8.3
8.8
6.9
6.4
B6V
8.9
6.3
7.2
5.9
9.4
7.6
8.1
6.2
5.7
B9V
8.2
5.6
6.5
5.8
9.1
7.3
7.8
6.8
5.3
A1V
6.9
4.3
5.2
4.6
8.4
6.7
7.1
5.2
4.7
A3V
5.5
2.6
3.9
3.0
8.0
6.2
6.6
5.7
4.2
A5V
2.4
-0.2
0.0
-0.3
7.4
5.7
6.0
5.1
3.5
A9IV
2.3
-0.3
-0.2
-0.5
7.2
5.5
5.9
4.9
3.4
F2V
-0.8
6.7
5.1
5.3
4.3
2.8
F4V
-0.9
6.6
5.0
5.2
4.2
2.7
F6V
-1.0
6.6
5.0
5.1
4.1
2.6
F8V
-0.9
6.3
4.7
4.8
3.6
2.3
G2V
6.1
4.5
4.5
3.4
2.0
G5IV
5.4
3.8
3.9
2.7
1.4
G7IV
4.4
2.6
2.6
1.0
0.2
K0IV
4.1
2.2
2.2
0.6
-0.2
K4V
3.8
1.7
1.8
0.3
-0.5
K8V
3.6
1.5
1.6
0.0
-0.8
M2V
3.1
1.5
1.5
0.3
-0.9
M4V
3.0
1.3
1.3
0.1
-1.1
M6V
2.5
0.8
0.8
-0.3
-1.6
M8III
1.4
-0.3
-0.3
-1.5
-2.7
11.3
9.3
10.0
9.0
7.6
T~50000oK
ν-1
May 1996
11.5
8.0
8.9
7.2
9.7
6.2
8.8
6.2
9.0
8.2
STIS Instrument Science Report 96-021
7.7
7.2
9.1
Page 8
Table 6. Local count rate STMAG limits for spectroscopic modes (25 counts/sec/pixel)
Sp type
G140L
G140M
E140M
E140H
G230L
G230M
E230M
E230H
Prism
O5V
13.3
9.9
8.8
6.3
12.8
8.9
7.5
5.6
11.8
B1V
12.7
9.3
8.3
5.8
12.3
8.3
7.1
5.1
11.4
B3V
11.8
8.4
7.3
4.9
11.5
7.5
6.3
4.4
10.7
B6V
10.5
7.1
6.3
3.7
10.7
6.7
5.6
3.6
10.1
B9V
9.9
6.4
5.6
3.1
10.4
6.4
5.3
3.3
9.8
A1V
8.5
5.1
4.5
1.9
9.7
5.7
4.7
2.7
9.3
A3V
7.0
3.6
3.2
0.5
9.4
5.3
4.3
2.3
9.1
A5V
4.5
0.4
0.4
8.9
4.8
3.9
1.8
8.8
A9IV
4.3
0.2
-1.2
8.8
4.7
3.7
1.7
8.6
F2V
1.6
8.5
4.5
3.6
1.5
8.6
F4V
1.5
8.4
4.4
3.5
1.4
8.5
F6V
1.5
8.4
4.4
3.5
1.4
8.6
F8V
1.6
8.3
4.3
3.4
1.3
8.6
G2V
-0.9
8.4
4.4
3.5
1.4
8.1
G5IV
-1.5
7.8
3.7
2.9
0.7
7.4
G7IV
7.0
2.8
1.9
-0.3
7.0
K0IV
6.6
2.4
1.5
-0.6
6.7
K4V
6.3
2.1
1.0
-1.2
6.5
K8V
6.3
2.4
1.4
-0.8
6.2
M2V
6.3
2.2
1.4
-0.7
5.5
M4V
6.2
2.0
1.2
-0.9
5.4
M6V
5.7
1.5
0.7
-1.4
4.9
M8III
4.5
0.3
-0.4
-2.5
3.7
T~50000oK
13.2
9.8
8.7
6.2
12.7
8.8
7.4
5.5
11.8
ν-1
9.6
6.1
3.7
2.7
10.4
6.3
5.3
3.3
14.2
May 1996
STIS Instrument Science Report 96-021
Page 9
Table 7. Local count rate STMAG limits for spectroscopic modes (50 counts/sec/pixel)
Sp type
G140L
G140M
E140M
E140H
G230L
G230M
E230M
E230H
Prism
O5V
12.6
9.2
8.0
5.5
12.0
8.1
6.8
4.8
11.1
B1V
12.0
8.6
7.6
5.0
11.5
7.6
6.3
4.3
10.7
B3V
11.1
7.6
6.6
4.1
10.7
6.7
5.6
3.6
9.9
B6V
9.8
6.3
5.5
3.0
10.0
5.9
4.9
2.9
9.3
B9V
9.1
5.7
4.9
2.3
9.7
5.6
4.6
2.6
9.1
A1V
7.7
4.3
3.7
1.1
9.0
4.9
4.0
1.9
8.6
A3V
6.2
2.8
2.5
-0.3
8.6
4.5
3.6
1.5
8.3
A5V
3.7
-0.4
-0.3
8.2
4.1
3.1
1.1
8.1
A9IV
3.5
-0.5
-2.0
8.0
3.9
3.0
0.9
7.9
F2V
0.9
7.7
3.7
2.9
0.7
7.9
F4V
0.7
7.6
3.6
2.8
0.6
7.8
F6V
0.7
7.7
3.6
2.8
0.6
7.9
F8V
0.8
7.6
3.5
2.7
0.5
7.8
G2V
7.7
3.6
2.8
0.6
7.3
G5IV
7.0
3.0
2.1
0.0
6.7
G7IV
6.2
2.0
1.1
-1.0
6.3
K0IV
5.9
1.7
0.8
-1.4
5.9
K4V
5.6
1.3
0.2
-1.9
5.7
K8V
5.6
1.6
0.6
-1.5
5.5
M2V
5.6
1.4
0.6
-1.5
4.8
M4V
5.4
1.2
0.4
-1.7
4.6
M6V
4.9
0.7
0.0
-2.2
4.1
M8III
3.8
-0.4
-1.2
-3.3
3.0
T~50000oK
12.4
9.0
7.9
5.4
11.9
8.0
6.7
4.7
11.0
ν-1
8.8
5.4
2.9
1.9
9.6
5.5
4.5
2.5
13.4
May 1996
STIS Instrument Science Report 96-021
Page 10
Table 8. Local count rate STMAG limits for spectroscopic modes (100 counts/sec/pixel)
Sp type
G140L
G140M
E140M
E140H
G230L
G230M
E230M
E230H
Prism
O5V
11.8
8.4
7.3
4.8
11.3
7.4
6.0
4.1
10.3
B1V
11.2
7.8
6.8
4.3
10.7
6.8
5.6
3.6
9.9
B3V
10.3
6.9
5.8
3.4
10.0
6.0
4.8
2.8
9.2
B6V
9.0
5.6
4.8
2.2
9.2
5.2
4.1
2.1
8.6
B9V
8.3
4.9
4.1
1.6
8.9
4.9
3.8
1.8
8.3
A1V
7.0
3.6
3.0
0.4
8.2
4.2
3.2
1.1
7.8
A3V
5.5
2.0
1.7
-1.0
7.9
3.8
2.8
0.8
7.6
A5V
2.9
-1.1
-1.1
7.4
3.3
2.4
0.3
7.3
A9IV
2.8
-1.3
7.2
3.2
2.2
0.2
7.1
F2V
0.1
7.0
3.0
2.1
0.0
7.1
F4V
0.0
6.9
2.8
2.0
-0.1
7.0
F6V
0.0
6.9
2.9
2.0
-0.1
7.1
F8V
0.1
6.8
2.8
1.9
-0.2
7.0
G2V
-2.4
6.9
2.9
2.0
-0.1
6.6
G5IV
-3.0
6.3
2.2
1.4
-0.8
5.9
G7IV
-10.7
5.5
1.3
0.4
-1.8
5.5
K0IV
-11.1
5.1
0.9
0.0
-2.1
5.1
K4V
-10.6
4.8
0.6
-0.5
-2.7
5.0
K8V
-10.8
4.8
0.8
-0.1
-2.3
4.7
M2V
-10.5
4.8
0.7
-0.1
-2.2
4.0
M4V
-10.7
4.6
0.5
-0.3
-2.4
3.9
M6V
-11.2
4.2
0.0
-0.8
-2.9
3.4
M8III
-12.4
3.0
-1.2
-1.9
-4.1
2.2
T~50000oK
11.7
8.3
7.1
4.7
11.2
7.3
5.9
4.0
10.3
ν-1
8.0
4.6
2.1
1.2
8.9
4.8
3.8
1.8
12.7
May 1996
STIS Instrument Science Report 96-021
Page 11
Table 9. Local count rate STMAG limits for spectroscopic modes (200 counts/sec/pixel)
Sp type
G140L
G140M
E140M
E140H
G230L
G230M
E230M
E230H
O5V
11.1
7.7
6.5
4.0
10.5
B1V
10.5
7.1
6.0
3.5
B3V
9.5
6.1
5.1
B6V
8.3
4.8
B9V
7.6
A1V
Prism
6.6
5.2
3.3
9.6
10.0
6.0
4.8
2.8
9.2
2.6
9.2
5.2
4.1
2.1
8.4
4.0
1.5
8.5
4.4
3.4
1.4
7.8
4.2
3.3
0.8
8.2
4.1
3.1
1.1
7.6
6.2
2.8
2.2
-0.4
7.5
3.4
2.4
0.4
7.1
A3V
4.7
1.3
0.9
-1.8
7.1
3.0
2.1
0.0
6.8
A5V
2.2
6.7
2.6
1.6
-0.4
6.6
A9IV
2.0
6.5
2.4
1.5
-0.6
6.4
F2V
-0.7
6.2
2.2
1.4
-0.8
6.4
F4V
-0.8
6.1
2.1
1.2
-0.9
6.3
F6V
-0.8
6.2
2.1
1.3
-0.9
6.4
F8V
-0.7
6.1
2.0
1.2
-1.0
6.3
G2V
6.2
2.1
1.3
-0.9
5.8
G5IV
5.5
1.5
0.6
-1.5
5.2
G7IV
4.7
0.5
-0.4
-2.5
4.8
K0IV
4.4
0.2
-0.8
-2.9
4.4
K4V
4.1
-0.2
-1.3
-3.4
4.2
K8V
4.1
0.1
-0.9
-3.0
4.0
M2V
4.1
-0.1
-0.9
-3.0
3.3
M4V
3.9
-0.3
-1.1
-3.2
3.1
M6V
3.4
-0.8
-1.5
-3.7
2.6
M8III
2.3
-1.9
-2.7
-4.8
1.5
T~50000oK
10.9
7.5
6.4
3.9
10.4
6.5
5.2
3.2
9.5
ν-1
7.3
3.9
1.4
0.4
8.1
4.0
3.0
1.0
11.9
May 1996
STIS Instrument Science Report 96-021
Page 12
Table 10. STMAG limits for a point sources limit of 25 counts/sec/pixel (FUV filters)
Sp type
MIR
Qtz
Cn182
Lyα
SRF2
ND1
O5V
20.4
18.6
16.2
16.1
19.7
17.9
B1V
19.8
18.2
15.8
15.2
19.2
17.3
B3V
18.9
17.3
14.9
14.1
18.3
16.4
B6V
17.8
16.4
14.0
12.7
17.3
15.3
B9V
17.1
15.9
13.5
11.5
16.7
14.6
A1V
15.7
14.9
12.7
7.9
15.5
13.2
A3V
14.4
13.8
11.9
6.5
14.2
11.9
A5V
11.4
11.3
10.1
0.5
11.2
8.9
A9IV
11.2
11.1
9.9
0.3
11.0
8.7
F2V
8.2
8.0
7.0
8.0
5.7
F4V
8.1
7.9
6.9
7.9
5.6
F6V
8.0
7.9
6.9
7.8
5.5
F8V
8.1
8.0
7.0
7.9
5.6
G2V
5.8
5.7
4.6
5.6
3.3
G5IV
5.1
5.0
4.0
4.9
2.6
G7IV
-1.7
-1.8
T~50000oK
20.3
18.6
16.2
15.9
19.6
17.8
ν-1
16.8
15.1
13.7
12.5
16
14.3
K0IV
K4V
K8V
M2V
M4V
M6V
M8III
May 1996
STIS Instrument Science Report 96-021
Page 13
Table 11. STMAG limits for a point sources limit of 50 counts/sec/pixel (FUV filters)
Sp type
MIR
Qtz
Cn182
Lyα
SRF2
ND1
O5V
19.6
17.9
15.5
15.3
18.9
17.1
B1V
19.1
17.5
15.0
14.4
18.5
16.6
B3V
18.1
16.6
14.2
13.3
17.5
15.6
B6V
17.0
15.7
13.3
12.0
16.6
14.5
B9V
16.3
15.1
12.8
10.7
15.9
13.8
A1V
15.0
14.2
11.9
7.2
14.7
12.5
A3V
13.6
13.1
11.2
5.7
13.4
11.1
A5V
10.6
10.5
9.3
-0.3
10.4
8.1
A9IV
10.5
10.3
9.1
-0.4
10.3
8.0
F2V
7.4
7.3
6.2
7.2
4.9
F4V
7.3
7.2
6.1
7.1
4.8
F6V
7.3
7.2
6.1
7.1
4.8
F8V
7.4
7.3
6.2
7.2
4.9
G2V
5.0
4.9
3.9
4.8
2.5
G5IV
4.4
4.3
3.2
4.2
1.9
T~50000oK
19.5
17.8
15.4
15.2
18.9
17.0
ν-1
16.1
14.4
12.9
11.7
15.2
13.6
G7IV
K0IV
K4V
K8V
M2V
M4V
M6V
M8III
May 1996
STIS Instrument Science Report 96-021
Page 14
Table 12. STMAG limits for a point sources limit of 100 counts/sec/pixel (FUV filters)
Sp type
May 1996
MIR
Qtz
Cn182
Lyα
SRF2
ND1
O5V
18.9
17.1
14.7
14.6
18.2
16.4
B1V
18.3
16.7
14.3
13.7
17.7
15.8
B3V
17.4
15.8
13.4
12.6
16.8
14.9
B6V
16.3
14.9
12.5
11.2
15.8
13.8
B9V
15.5
14.4
12.0
10.0
15.2
13.0
A1V
14.2
13.4
11.2
6.4
14.0
11.7
A3V
12.9
12.3
10.4
4.9
12.7
10.4
A5V
9.9
9.8
8.6
-1.0
9.7
7.4
A9IV
9.7
9.6
8.4
-1.2
9.5
7.2
F2V
6.7
6.5
5.5
-5.7
6.5
4.2
F4V
6.5
6.4
5.4
-5.8
6.3
4.0
F6V
6.5
6.4
5.4
-5.9
6.3
4.0
F8V
6.6
6.5
5.5
-6.5
6.4
4.1
G2V
4.3
4.2
3.1
-9.2
4.1
1.8
G5IV
3.6
3.5
2.5
-9.9
3.4
1.1
G7IV
-3.2
-3.3
-6.2
0.0
-3.4
-5.7
K0IV
-3.6
-3.7
-6.6
0.0
-3.8
-6.1
K4V
-3.2
-3.3
-6.0
0.0
-3.4
-5.7
K8V
-3.5
-3.6
-6.3
0.0
-3.7
-6.0
M2V
-3.1
-3.3
-6.0
0.0
-3.4
-5.6
M4V
-3.3
-3.4
-6.2
0.0
-3.5
-5.8
M6V
-3.8
-3.9
-6.7
0.0
-4.0
-6.3
M8III
-5.0
-5.1
-7.8
0.0
-5.2
-7.5
T~50000oK
18.8
17.1
14.7
14.4
18.1
16.3
ν-1
15.3
13.6
12.2
11.0
14.5
12.8
STIS Instrument Science Report 96-021
Page 15
Table 13. STMAG limits for a point sources limit of 200 counts/sec/pixel (FUV filters)
Sp type
MIR
Qtz
Cn182
Lyα
SRF2
ND1
O5V
18.1
16.4
14.0
13.8
17.4
15.6
B1V
17.6
16.0
13.5
12.9
17.0
15.1
B3V
16.6
15.1
12.7
11.8
16.0
14.1
B6V
15.5
14.2
11.8
10.5
15.0
13.0
B9V
14.8
13.6
11.3
9.2
14.4
12.3
A1V
13.5
12.7
10.4
5.7
13.2
11.0
A3V
12.1
11.6
9.7
4.2
11.9
9.6
A5V
9.1
9.0
7.8
-1.8
8.9
6.6
A9IV
9.0
8.8
7.6
8.8
6.5
F2V
5.9
5.8
4.7
5.7
3.4
F4V
5.8
5.7
4.6
5.6
3.3
F6V
5.8
5.7
4.6
5.6
3.3
F8V
5.9
5.8
4.7
5.7
3.4
G2V
3.5
3.4
2.3
3.3
1.0
G5IV
2.9
2.8
1.7
2.7
0.4
T~50000oK
18.0
16.3
13.9
13.7
17.4
15.5
ν-1
14.6
12.9
11.4
10.2
13.7
12.1
G7IV
K0IV
K4V
K8V
M2V
M4V
M6V
M8III
May 1996
STIS Instrument Science Report 96-021
Page 16
Table 14. STMAG limits for a point sources limit of 25 counts/sec/pixel (NUV filters)
Sp. type
MIR
CIII
CN182
Cn270
MGII
Qtz
SRF2
ND1
O5V
20.8
16.3
18.2
17.9
16.0
20.5
20.6
18.3
B1V
20.4
15.8
17.7
17.5
15.6
20.1
20.1
17.9
B3V
19.5
14.9
16.8
16.8
15.0
19.3
19.3
17.0
B6V
18.7
14.0
15.9
16.1
14.4
18.5
18.5
16.2
B9V
18.4
13.7
15.6
15.9
14.1
18.2
18.1
15.9
A1V
17.7
13.0
14.8
15.2
13.5
17.5
17.4
15.2
A3V
17.1
12.5
14.2
14.8
13.1
17.0
16.9
14.6
A5V
16.5
11.5
13.1
14.3
12.5
16.3
16.2
14.0
A9IV
16.3
11.3
12.9
14.1
12.3
16.1
16.0
13.8
F2V
15.8
8.7
10.3
13.7
11.9
15.5
15.5
13.3
F4V
15.7
8.6
10.2
13.6
11.8
15.4
15.3
13.2
F6V
15.6
8.5
10.1
13.5
11.9
15.4
15.3
13.1
F8V
15.4
8.7
10.3
13.2
11.4
15.1
15.1
12.9
G2V
15.1
6.4
8.2
13.0
11.2
14.9
14.8
12.6
G5IV
14.5
5.8
7.6
12.3
10.5
14.2
14.1
12.0
G7IV
13.7
3.9
10.8
9.4
13.1
13.1
11.2
K0IV
13.3
3.5
10.4
9.1
12.8
12.7
10.8
K4V
13.1
4.1
10.0
9.1
12.4
12.3
10.6
K8V
13.0
3.8
10.1
9.5
12.3
12.2
10.5
M2V
12.5
4.1
10.1
9.3
11.9
11.8
10.0
M4V
12.4
3.9
9.9
9.2
11.7
11.6
9.9
M6V
12.1
3.4
9.4
8.7
11.2
11.1
9.6
M8III
11.6
2.3
8.3
7.5
10.1
10.0
9.1
T~50000oK
20.8
16.2
18.1
17.8
16.0
20.5
20.5
18.3
ν-1
18.3
13.8
15.9
15.7
14.0
18.1
18.1
15.8
May 1996
STIS Instrument Science Report 96-021
Page 17
Table 15. STMAG limits for a point sources limit of 50 counts/sec/pixel (NUV filters)
Sp. type
MIR
CIII
CN182
Cn270
MGII
Qtz
SRF2
ND1
O5V
20.1
15.5
17.4
17.1
15.3
19.8
19.8
17.6
B1V
19.6
15.1
17.0
16.7
14.9
19.3
19.4
17.1
B3V
18.8
14.1
16.1
16.1
14.3
18.5
18.5
16.3
B6V
18.0
13.2
15.2
15.4
13.6
17.7
17.7
15.5
B9V
17.6
13.0
14.8
15.1
13.3
17.4
17.4
15.1
A1V
16.9
12.3
14.1
14.5
12.7
16.7
16.7
14.4
A3V
16.4
11.7
13.5
14.1
12.4
16.2
16.1
13.9
A5V
15.7
10.7
12.3
13.5
11.8
15.5
15.5
13.2
A9IV
15.6
10.6
12.2
13.4
11.6
15.4
15.3
13.1
F2V
15.0
7.9
9.5
12.9
11.1
14.8
14.7
12.5
F4V
14.9
7.8
9.4
12.8
11.0
14.7
14.6
12.4
F6V
14.9
7.8
9.4
12.8
11.1
14.7
14.6
12.4
F8V
14.6
7.9
9.6
12.4
10.6
14.4
14.3
12.1
G2V
14.4
5.7
7.4
12.2
10.4
14.1
14.0
11.9
G5IV
13.8
5.0
6.8
11.6
9.8
13.5
13.4
11.3
G7IV
12.9
3.1
10.0
8.7
12.4
12.3
10.4
K0IV
12.6
2.8
9.6
8.3
12.0
11.9
10.1
K4V
12.4
3.3
9.3
8.3
11.7
11.6
9.9
K8V
12.2
3.0
9.4
8.7
11.5
11.4
9.7
M2V
11.8
3.3
9.3
8.6
11.1
11.0
9.3
M4V
11.7
3.2
9.1
8.4
10.9
10.9
9.2
M6V
11.3
2.7
8.7
7.9
10.4
10.4
8.8
M8III
10.8
1.5
7.5
6.8
9.3
9.2
8.3
T~50000oK
20.0
15.5
17.4
17.1
15.2
19.7
19.7
17.5
ν-1
17.5
13.0
15.1
15
13.3
17.3
17.3
15.0
May 1996
STIS Instrument Science Report 96-021
Page 18
Table 16. STMAG limits for a point sources limit of 100 counts/sec/pixel (NUV filters)
Sp. type
MIR
CIII
CN182
Cn270
MGII
Qtz
SRF2
ND1
O5V
19.3
14.8
16.7
16.4
14.5
19.0
19.1
16.8
B1V
18.9
14.3
16.2
16.0
14.1
18.6
18.6
16.4
B3V
18.0
13.4
15.3
15.3
13.5
17.8
17.8
15.5
B6V
17.2
12.5
14.4
14.6
12.9
17.0
17.0
14.7
B9V
16.9
12.2
14.1
14.4
12.6
16.7
16.6
14.4
A1V
16.2
11.5
13.3
13.7
12.0
16.0
15.9
13.7
A3V
15.6
11.0
12.7
13.3
11.6
15.5
15.4
13.1
A5V
15.0
10.0
11.6
12.8
11.0
14.8
14.7
12.5
A9IV
14.8
9.8
11.4
12.6
10.8
14.6
14.5
12.3
F2V
14.3
7.2
8.8
12.2
10.4
14.0
13.9
11.8
F4V
14.2
7.1
8.7
12.1
10.3
13.9
13.8
11.7
F6V
14.1
7.0
8.6
12.0
10.3
13.9
13.8
11.6
F8V
13.9
7.2
8.8
11.7
9.9
13.6
13.5
11.4
G2V
13.6
4.9
6.7
11.5
9.7
13.3
13.3
11.1
G5IV
13.0
4.3
6.0
10.8
9.0
12.7
12.6
10.5
G7IV
12.2
0.0
2.4
9.2
7.9
11.6
11.6
9.7
K0IV
11.8
0.0
2.0
8.9
7.6
11.3
11.2
9.3
K4V
11.6
0.0
2.5
8.5
7.6
10.9
10.8
9.1
K8V
11.5
0.0
2.3
8.6
8.0
10.8
10.7
9.0
M2V
11.0
0.0
2.6
8.6
7.8
10.4
10.3
8.5
M4V
10.9
0.0
2.4
8.4
7.7
10.2
10.1
8.4
M6V
10.5
0.0
1.9
7.9
7.2
9.7
9.6
8.0
M8III
10.1
0.0
0.8
6.8
6.0
8.6
8.5
7.6
T~50000oK
19.3
14.7
16.6
16.3
14.5
19.0
19.0
16.8
ν-1
16.8
12.3
14.4
14.2
12.5
16.6
16.5
14.3
May 1996
STIS Instrument Science Report 96-021
Page 19
Table 17. STMAG limits for a point sources limit of 200 counts/sec/pixel (NUV filters)
Sp. type
MIR
CIII
CN182
Cn270
MGII
Qtz
SRF2
ND1
O5V
18.6
14.0
15.9
15.6
13.8
18.3
18.3
16.1
B1V
18.1
13.5
15.5
15.2
13.4
17.8
17.9
15.6
B3V
17.3
12.6
14.6
14.6
12.8
17.0
17.0
14.8
B6V
16.5
11.7
13.7
13.9
12.1
16.2
16.2
14.0
B9V
16.1
11.5
13.3
13.6
11.8
15.9
15.9
13.6
A1V
15.4
10.8
12.6
13.0
11.2
15.2
15.2
12.9
A3V
14.9
10.2
12.0
12.5
10.9
14.7
14.6
12.4
A5V
14.2
9.2
10.8
12.0
10.3
14.0
13.9
11.7
A9IV
14.0
9.1
10.7
11.9
10.1
13.9
13.8
11.5
F2V
13.5
6.4
8.0
11.4
9.6
13.3
13.2
11.0
F4V
13.4
6.3
7.9
11.3
9.5
13.2
13.1
10.9
F6V
13.4
6.3
7.9
11.3
9.6
13.2
13.1
10.9
F8V
13.1
6.4
8.1
10.9
9.1
12.9
12.8
10.6
G2V
12.9
4.2
5.9
10.7
8.9
12.6
12.5
10.4
G5IV
12.2
3.5
5.3
10.1
8.3
11.9
11.9
9.7
G7IV
11.4
1.6
8.5
7.2
10.9
10.8
8.9
K0IV
11.1
1.3
8.1
6.8
10.5
10.4
8.6
K4V
10.8
1.8
7.8
6.8
10.2
10.1
8.3
K8V
10.7
1.5
7.9
7.2
10.0
9.9
8.2
M2V
10.3
1.8
7.8
7.1
9.6
9.5
7.8
M4V
10.1
1.7
7.6
6.9
9.4
9.3
7.6
M6V
9.8
1.2
7.1
6.4
8.9
8.9
7.3
M8III
9.3
0.0
6.0
5.3
7.8
7.7
6.8
T~50000oK
18.5
13.9
15.9
15.6
13.7
18.2
18.2
16.0
ν-1
16.0
11.5
13.6
13.5
11.8
15.8
15.8
13.5
May 1996
STIS Instrument Science Report 96-021
Page 20
Table 18. Diffuse flux limits for the STIS spectroscopic observing configurations
Observing
configuration
25 counts/sec/pixel
(ergs/sec/cm2/Å/
arcsec2)
50 counts/sec/pixel
(ergs/sec/cm2/Å/
arcsec2)
100 counts/sec/pixel
(ergs/sec/cm2/Å/
arcsec2)
200 counts/sec/pixel
(ergs/sec/cm2/Å/
arcsec2)
Mir (FUV)
8.4E-13
1.7E-12
3.4E-12
6.7E-12
Qtz (FUV)
2.9E-12
5.7E-12
1.1E-11
2.3E-11
Cn182 (FUV)
2.1E-11
4.2E-11
8.4E-11
1.7E-10
Lyα (FUV)
4.2E-11
8.5E-11
1.7E-10
3.4E-10
SrF2 (FUV)
1.4E-12
2.8E-12
5.5E-12
1.1E-11
ND1 (FUV)
8.4E-12
1.7E-11
3.4E-11
6.7E-11
Mir (NUV)
1.7E-13
3.4E-13
6.9E-13
1.4E-12
CIII (NUV)
1.8E-11
3.6E-11
7.3E-11
1.5E-10
Cn182 (NUV)
3.5E-12
6.9E-12
1.4E-11
2.8E-11
Cn270 (NUV)
1.4E-12
2.7E-12
5.4E-12
1.1E-11
MgII (NUV)
6.4E-12
1.3E-11
2.6E-11
5.2E-11
Qtz (NUV)
2.0E-13
4.1E-13
8.2E-13
1.6E-12
SrF2 (NUV)
2.2E-13
4.3E-13
8.6E-13
1.7E-12
ND1 (NUV)
1.7E-12
3.4E-12
6.9E-12
1.4E-11
Table 19. Line flux limits for the STIS spectroscopic observing configurations
Observing
configuration
25 counts/sec/pixel
(ergs/sec/cm2/Å)
50 counts/sec/pixel
(ergs/sec/cm2/Å)
100 counts/sec/pixel
(ergs/sec/cm2/Å)
200 counts/sec/pixel
(ergs/sec/cm2/Å)
g140l
2.4E-12
4.8E-12
9.6E-12
1.9E-11
g140m
5.6E-11
1.1E-10
2.2E-10
4.5E-10
e140m
5.0E-10
1.0E-9
2.0E-9
4.0E-9
e140h
1.3E-9
2.6E-9
5.1E-9
1.0E-8
g230l
4.3E-13
8.6E-13
1.7E-12
3.5E-12
g230m
1.9E-11
3.8E-11
7.6E-11
1.5E-10
e230m
4.5E-11
8.9E-11
1.8E-10
3.6E-10
e230h
3.0E-10
5.9E-10
1.2E-9
2.4E-9
May 1996
STIS Instrument Science Report 96-021
Page 21