WFIRST: Grism Simulations
Abstract
The WFIRST galaxy redshift survey probes the nature of dark energy through the 3D clustering of galaxies. Realistic grism simulations are important for assessing its performance and modeling the systematic uncertainties. Our latest WFIRST grism simulation work consists of two components. The first component is the creation of slitless grism images with appropriate detector and spectral parameters, such as pixel scale, responsivity, detector position-dependent distortions, traces, offsets, and wavelength dispersions. The second component is the generation of the input lists that are to be fed into the simulation software. For these input lists we have developed three different methods: 1) Direct transfer of an already observed WFC3 grism field, 2) Non-realistic tests of parameter space, appropriate for examining the effects of altering a basic input parameter, like wavelength resolution, 3) Generation of a random, realistic sky field based on measured H-alpha luminosity functions, with observed distributions of equivalent width, size, J-H color, and major/minor axis ratios taken from HST WFC3 grism data (WISP Survey, PI: Malkan). We apply different parameter distributions for the emission-line and the non-emitting field galaxies and we also include star distributions based on galactic latitude, achieving a source density and object overlap consistent with the true sky. We discuss the use of these simulations for analysis and validation.
- Publication:
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American Astronomical Society Meeting Abstracts #231
- Pub Date:
- January 2018
- Bibcode:
- 2018AAS...23135512C