The GLASS James Webb Space Telescope Early Release Science Program. I. Survey Design and Release Plans

TL;DR

The GLASS-JWST-ERS program will provide the deepest extragalactic data from JWST, addressing key questions about cosmic reionization and baryon cycling, with plans for public data releases and broad scientific investigations.

Contribution

It introduces a comprehensive survey design and data release plan for the first deep extragalactic JWST observations targeting key cosmic questions.

Findings

Expected high sensitivity in NIRISS and NIRSpec spectroscopy.

Identification of target fields with different lensing properties.

Preparation of community for data access and analysis.

Abstract

The GLASS James Webb Space Telescope Early Release Science (hereafter GLASS-JWST-ERS) Program will obtain and make publicly available the deepest extragalactic data of the ERS campaign. It is primarily designed to address two key science questions, namely, "what sources ionized the universe and when?" and "how do baryons cycle through galaxies?", while also enabling a broad variety of first look scientific investigations. In primary mode, it will obtain NIRISS and NIRSpec spectroscopy of galaxies lensed by the foreground Hubble Frontier Field cluster, Abell 2744. In parallel, it will use NIRCam to observe two fields that are offset from the cluster center, where lensing magnification is negligible, and which can thus be effectively considered blank fields. In order to prepare the community for access to this unprecedented data, we describe the scientific rationale, the survey design (including target selection and observational setups), and present pre-commissioning estimates of the expected sensitivity. In addition, we describe the planned public releases of high-level data products, for use by the wider astronomical community.