FIGS—Faint Infrared Grism Survey: Description and Data Reduction

Abstract

The Faint Infrared Grism Survey (FIGS) is a deep Hubble Space Telescope (HST) WFC3/IR (Wide Field Camera 3 Infrared) slitless spectroscopic survey of four deep fields. Two fields are located in the Great Observatories Origins Deep Survey-North (GOODS-N) area and two fields are located in the Great Observatories Origins Deep Survey-South (GOODS-S) area. One of the southern fields selected is the Hubble Ultra Deep Field. Each of these four fields were observed using the WFC3/G102 grism (0.8 μm-1.15 μm continuous coverage) with a total exposure time of 40 orbits (≈100 kilo-seconds) per field. This reaches a s 3 continuum depth of »26 AB magnitudes and probes emission lines to~---10 erg s cm 17 12 . This paper details the four FIGS fields and the overall observational strategy of the project. A detailed description of the Simulation Based Extraction (SBE) method used to extract and combine over 10,000 spectra of over 2000 distinct sources brighter than = m 26.5mag is provided. High fidelity simulations of the observations is shown to significantly improve the background subtraction process, the spectral contamination estimates, and the final flux calibration. This allows for the combination of multiple spectra to produce a final high quality, deep, 1D spectra for each object in the survey.

A Catalog of Emission-line Galaxies from the Faint Infrared Grism Survey: Studying Environmental Influence on Star Formation

“…In this paper, we used 1D spectra of individual PAs which were generated using the methods described in Pirzkal et al (2017). Here we briefly summarize this process.…”

“…We refer the reader to Pirzkal et al (2017) for a complete description of these processes. Pirzkal et al (2017) also describes a method for combining individual PAs into a single 1D spectrum, though we do not use the combined spectra here. Individual PAs are subject to different levels of contamination, and depending on the location of the emission line region, they may not all exhibit the same line emission.…”

Emission-line Metallicities from the Faint Infrared Grism Survey and VLT/MUSE

“…In this paper, we used 1D spectra which were generated using the methods described in Pirzkal et al (2017). Here we briefly summarize this process.…”

The James Webb Space Telescope North Ecliptic Pole Time-domain Field. I. Field Selection of a JWST Community Field for Time-domain Studies

“…During most of its operational lifetime, the depth and areal efficiency of HST grism spectroscopic surveys has added valuable low-resolution spectra to many of the deepest HST imaging surveys, which was essential to measure the redshifts and characterize the properties of faint objects. Prime examples of such HST grism surveys are the Grism ACS Project for Extragalactic Science (GRAPES; e.g., Pirzkal et al 2004;Pasquali et al 2006), the ACS Probing Evolution and Reionization Spectroscopically (PEARS; e.g., Pirzkal et al 2013;Straughn et al 2008Straughn et al , 2009, the WFC3 grism survey (3DHST; e.g., Momcheva et al 2016), the WFC3 Infrared Spectroscopic Parallel survey (WISP; e.g., Atek et al 2010), the Grism Lens-Amplified Survey from Space (GLASS; e.g., Treu et al 2015;Schmidt et al 2014), and the Faint Infrared Grism Survey (FIGS; e.g., Pirzkal et al 2017;Larson et al 2018). We note that of these only WISP was an HST parallel survey.…”