Synphot Data User's Guide


1.1 Current Instruments

This section describes the keywords available for the science instruments installed on HST as of January, 2007: the Advanced Camera for Surveys (ACS), the Fine Guidance Sensor (FGS), the Near Infrared Camera and Multi-Object Spectrograph (NICMOS), the Space Telescope Imaging Spectrograph (STIS), and the Wide Field Planetary Camera 2 (WFPC2).

1.1.1 ACS

The ACS keywords consist of a list of detectors, filters, extraction apertures, and Modified Julian Date specification. The coronagraphic mode may be used only with the HRC detector.

The mjd keyword is used to specify the Modified Julian Date which is used to account for time-dependent sensitivity. For more details, see Section 2.3.

As of this writing in June 2008, though, it was unclear what changes will be needed to successfully model ACS after its repair in Servicing Mission 4 (SM$). More information about any changes for post-SM4 ACS configurations will be made available online as it becomes available at:

Table 1.1: ACS Keywords
Detectors hrc sbc wfc1wfc2
Filters for hrc: f220w f250w f330w f344n f435w f475w f502n f550m f555w f606w f625w f658n f660n f775w f814w f850lp f892n pol_uv pol_v
Ramp filters for hrc: fr388n fr459m fr505n fr656n fr914m
Dispersers for hrc: g800l pr200l
Filters for wfc: f435w f475w f502n f550m f555w f606w f625w f658n f660n f775w f814w f850lp f892n pol_uv pol_v
Ramp filters for wfc: fr1016n fr388n fr423n fr459m fr462n fr505n fr551n fr601n fr647m fr656n fr716n fr782n fr853n fr914m fr931n Dispersers for wfc:g800l
Filters for sbc: f115lp f125lp f140lp f150lp f165lp f122m
Dispersers for sbc: pr110l pr130l
Encircled energy radius values: aper#0.0 aper#0.1 aper#0.2 aper#0.3 aper#0.4 aper#0.5 aper#0.6 aper#0.8 aper#1.0 aper#1.5 aper#2.0 aper#4.0
Modified Julian Date mjd#
Other coron

1.1.2 FGS

The FGS instrument keywords consist of a list of filters plus a coordinate axis. Some of the filter names are aliases for other filters. "astroclear" is an alias for "F605W", "clear" is an alias for "F583W", "red" is an alias for "F650W", and "yellow" is an alias for "F550W". One example of an FGS observation mode string would be "FGS,F583W,Y".

Table 1.2: FGS Keywords
Filter f550w (yellow) f583w (clear) f605w (astroclear) f650w (red) nd5 pupil
Axis x y

1.1.3 NICMOS

The NICMOS keywords consist of a list of filters, grisms, polarizers, and detectors. Both the filter name and camera number are required in the observation mode. (The detector keyword tacq is another way to specify detector 2.)

The dn keyword is used to divide throughputs by the analog-to-digital converter (ADC) gain ratio, which transforms results from units of electrons to data numbers (DNs).

For thermal calculations, all component keywords except the detector may be parameterized for temperature. For more information, see Section 2.5.

Table 1.3: NICMOS Keywords
Detectors 1 2 3 tacq
Filters for Camera 1 blank f090m f095n f097n f108n f110m f110w f113n f140w f145m f160w f164n f165m f166n f170m f187n f190n pol0s pol120s pol240s
Filters for Camera 2 blank f100w f160w f165m f171m f180m f187n f187w f190n f204m f205w f207m f212n f215n f216n f222m f237m pol0l pol120l pol240l
Filters for Camera 3 blank f108n f110w f113n f150w f160w f164n f166n f175w f187n f190n f196n f200n f212n f215n f222m f240m g096 g141 g206
ADC gain dn
Thermal components spider primary pads hole sec edge bend1 reimag pupil image para1 para2 bend dewar cmask dqe

1.1.4 STIS

The available keywords for STIS include filters, apertures, gratings, central wavelengths, and ADC gains. Each grating or imaging mirror can be used with only one of the three STIS detectors (CCD, NUVMAMA, or FUVMAMA); specifying the grating automatically determines the detector. If no central wavelength is specified, results will be calculated for the entire bandpass of the grating. The ADC gain keywords only apply to the STIS CCD modes and are used to convert results from units of electrons to DNs.

In addition to the aperture names as given in Table 1.4, synphot will recognize aperture names as given in the format used for phase 2 proposals. For example, the aperture name "52X0.05" is equivalent to the aperture "s52x005" listed in the table.

The mjd keyword is used to specify the Modified Julian Date which is used to account for time-dependent sensitivity of the FUV and NUV MAMAs. For more details, see Section 2.3.

For important additional details about specifying STIS obsmodes, see Section 3.2.

As of January, 2007, STIS is in safe mode due to the failure of the Side 2 power supply in August 2004 (Side 1 had failed in 2001). However, replacement of the Side 2 electronics of STIS is planned during the upcoming HST Servicing Mission 4. If this is successful, STIS will be back in operation.

Table 1.4: STIS Keywords
Filters 25mama 50ccd 50coron f25ciii f25cn182 f25cn270 f25lya f25mgii f25nd3 f25nd5 f25ndq1 f25ndq2 f25ndq3 f25ndq4 f25qtz f25srf2 f28x50lp f28x50oii f28x50oiii
Apertures s005x29 s005x31nda s005x31ndb s009x29 s01x003 s01x006 s01x009 s01x02 s02x005nd s02x006 s02x006fpa s02x006fpb s02x006fpc s02x006fpd s02x006fpe s02x009 s02x02 s02x02fpa s02x02fpb s02x02fpc s02x02fpd s02x02fpe s02x05 s02x29 s03x005nd s03x006 s03x009 s03x02 s05x05 s10x006 s10x02 s2x2 s31x005nda s31x005ndb s31x005ndc s36x005n45 s36x005p45 s36x06n45 s36x06p45 s52x005 s52x01 s52x02 s52x05 s52x2 s6x006 s6x02 s6x05 s6x6
Gratings e140h e140hb e140m e140mb e230h e230m g140l g140lb g140m g140mb g230l g230lb g230m g230mb g430l g430m g750l g750m prism x140 x140m x230 x230h
Mirrors acq ccd fuvmama nuvmama
Central wavelengths all c1687 c1769 c1851 c1933 c2014 c2095 c2176 c2257 c2338 c2419 c2499 c2579 c2659 c2739 c2818 c2898 c2977 c3055 c3134 i1884 i2600 i2800 i2828 c1713 c1854 c1995 c2135 c2276 c2416 c2557 c2697 c2836 c2976 c3115 i2794 c1978 c2707 i2124 i2269 i2415 i2561 c1763 c2013 c2263 c2513 c2762 c3012 i1813 i1863 i1913 i1963 i2063 i2113 i2163 i2213 i2313 i2363 i2413 i2463 i2563 i2613 i2663 i2713 i2812 i2862 i2912 i2962 c3165 c3423 c3680 c3936 c4194 c4451 c4706 c4961 c5216 c5471 i3305 i3843 i4781 i5093 c1173 c1222 c1272 c1321 c1371 c1420 c1470 c1518 c1567 c1616 c1665 c1714 i1218 i1387 i1400 i1540 i1550 i1640 c1425 c1234 c1416 c1598 i1271 i1307 i1343 i1380 i1453 i1489 i1526 i1562 c7751 c8975 c10363 c10871 c5734 c6252 c6768 c7283 c7795 c8311 c8825 c9336 c9851 i6094 i6581 i8561 i9286 i9806
ADC Gains a2d1 a2d2 a2d3 a2d4
Modified Julian Date mjd#

1.1.5 WFPC2

The WFPC2 keywords consist of a list of detectors, filters, and miscellaneous keywords. The miscellaneous keywords include the ADC gain keywords a2d7 and a2d15, which convert results from units of electrons to data numbers (DNs); cal, which accounts for the flat-field response; lrf#, which is used for the linear ramp filters; and cont#, which accounts for changes in throughput between decontamination events (see Chapter 2 for more details on the latter two). Due to the removal of WFPC2 during SM4, time-dependent effects in WFPC2 computations will only be valid for parameterized dates prior to SM4.

The WFPC2 has twelve filter wheels, each of which has five positions, including a clear position. Detector 1 is the PC chip; detectors 2 through 4 are the Wide Field chips. If a detector is not specified, the default is #4. A typical WFPC2 observation mode string would be "WFPC2,F450W,2".

Table 1.5: WFPC2 Keywords
Detectors 1 2 3 4
Miscellaneous a2d7 a2d15 cal cont#
Filter Wheel 1 f122m f157w f160bw f953n
Filter Wheel 2 f130lp f165lp f785lp f850lp
Filter Wheel 3 f336w f410m f467m f547m
Filter Wheel 4 f439w f569w f675w f791w
Filter Wheel 5 f343n f375n f390n f437n
Filter Wheel 6 f469n f487n f502n f588n
Filter Wheel 7 f631n f656n f658n f673n
Filter Wheel 8 f170w f185w f218w f255w
Filter Wheel 9 f300w f380w f555w f622w
Filter Wheel 10 f450w f606w f702w f814w
Filter Wheel 11 f1042m fqunv fqunv33 fqch4n fqch4n33 fqch4n15 fqch4p15 polq polq_par polq_perp polqn33 polqn18 polqp15
Filter Wheel 12 lrf#

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