WFC3 G102 Calibrations

If you are using slitlessutils for G102 grism reduction and analysis, all the necessary calibration and reference files are accessible from the software directly.  See the configuration documentation for slitlessutils and/or the grism data analysis webpage.

The configuration files presented on this page are in the correct format to be used with the HSTaXe extraction software, which is no longer a STScI-supported package.

The files linked here are based on the older 2015 calibrations. To use these calibration products with the deprecated HSTaXe, copy them into a directory and set your AXE_CONFIG_PATH environment variable to point to that directory.

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The files were created using both ground-test (flat-field cube) and in-flight data (sensitivity and master sky). Details are given in the following WFC3 Instrument Science Reports:

• ISR 2008-16: "The TV3 ground calibrations of the WFC3 NIR grisms"
• ISR 2009-18: "WFC3 SMOV proposal 11552: Calibration of the G102 grism"
• ISR 2011-01: "Master sky images for the WFC3 G102 and G141 grisms"
• ISR 2011-05: "Revised Flux Calibration of the WFC3 G102 and G141 grisms"
• ISR 2016-15: "Trace and Wavelength Calibrations of the WFC3 G102 and G141 IR Grisms.”

Calibrations are derived based on object positions determined from F098M direct imaging. Offsets from ISR 2010-12  ("Proposal 11913-IR Filter Wedge Check") should be applied if positions are determined from imaging in other filters.

The master sky image should only be applied to data reprocessed using calwf3 v2.0 or later. It is also necessary to use them together with the aXe configuration file WFC3.IR.G102.V1.0.conf or later. ISR 2011-01  gives details of how the master sky images were created.

Feb 5, 2016: Updated configuration files are now avaialble for a range of grism-filter combinations. Details on the data analysis are provided in ISR 2016-15: "Trace and Wavelength Calibrations of the WFC3 G102 and G141 IR Grisms."

Jan 24, 2011: Updated G102 sensitivity, flat-field, and configuration files are available, based on additional analysis of standard star data obtained in Cycle 17. The new files are designated as version 2. Note that the zeroth-order sensitivity file remains at version 1. Details of the data analysis are given in ISR 2011-05.

Nov 23, 2010: An updated G102 configuration file (V1.5) is available, which contains changes to fix a problem encountered when using the 'fluxcube' method in aXe to produce a contamination image. It was noticed that the zeroth-order spectra were not showing up in the contamination image and therefore that order was being neglected when estimating the contamination in spectra. The V1.5 configuration files contain appropriate changes to the definitions for the zeroth-order spectra (BEAM B) to fix this problem.