research

Lambda = 2.4 to 5 Micron Spectroscopy with the James Webb Space Telescope NIRCam Instrument

Abstract

The James Webb Space Telescope near-infrared camera (JWST NIRCam) has two 2'2 x 2'2 fields of view that can be observed with either imaging or spectroscopic modes. Either of two R approx.1500 grisms with orthogonal dispersion directions can be used for slitless spectroscopy over lambda = 2.4 - 5.0 microns in each module, and shorter wavelength observations of the same fields can be obtained simultaneously. We describe the design drivers and parameters of the grisms and present the latest predicted spectroscopic sensitivities, saturation limits, resolving powers, and wavelength coverage values. Simultaneous short wavelength (0.6 - 2.3 microns) imaging observations of the 2.4 - 5.0 microns spectroscopic field can be performed in one of several different filter bands, either in-focus or defocused via weak lenses internal to NIRCam. The grisms are available for single-object time series spectroscopy and wide-field multi-object slitless spectroscopy modes in the first cycle of JWST observations. We present and discuss operational considerations including subarray sizes and data volume limits. Potential scientific uses of the grisms are illustrated with simulated observations of deep extragalactic fields, dark clouds, and transiting exoplanets. Information needed to plan observations using these spectroscopic modes are also provided

Similar works

Full text

thumbnail-image

NASA Technical Reports Server

Provided a free PDF
oai:casi.ntrs.nasa.gov:20180002165Last time updated on 1/3/2019View original full text link

This paper was published in NASA Technical Reports Server.

Having an issue?

Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.