The Near-Infrared Spectrograph (NIRSpec) on theJames WebbSpace Telescope

Abstract

We present an overview of the capabilities and key algorithms employed in the so-called eMPT software suite developed for planning scientifically optimized, multi-object spectroscopic (MOS) observations with the Micro-Shutter Array (MSA) of the Near-Infrared Spectrograph (NIRSpec) instrument on board the James Webb Space Telescope, the first multi-object spectrograph to operate in space. NIRSpec MOS mode is enabled by a programmable MSA, a regular grid of ~250 000 individual apertures that projects to a static, semi-regular pattern of available slits on the sky and makes the planning and optimization of an MSA observation a rather complex task. As such, the eMPT package is offered to the NIRSpec user community as a supplement to the MSA Planning Tool (MPT) included in the STScI Astronomer’s Proposal Tool (APT) to assist in the planning of NIRSpec MOS proposals requiring advanced functionality to meet ambitious science goals. The eMPT produces output that can readily be imported and incorporated into the user’s observing program within the APT to generate a customized MPT MOS observation. Furthermore, its novel algorithms and modular approach make it highly flexible and customizable, providing users the option to finely control the workflow and even insert their own software modules to tune their MSA slit masks to the particular scientific objectives at hand.

Identification and properties of intense star-forming galaxies at redshifts z > 10

“…The camera features a field of view of 9.7 square arcmin for each of the short and long wavelength ranges, divided by a dichroic to allow surveying in both arms simultaneously. The Near-Infrared Spectrograph (NIRSpec) was also designed for this type of application, with a configurable multi-slit mask that allows spectra of many sources in a single exposure 34 . The JWST Advanced Deep Extragalactic Survey (JADES) is a collaboration of the NIRCam and NIRSpec teams to demonstrate and exploit these features by pooling over 750 hours of guaranteed time to conduct an ambitious study of galaxy evolution in the Great Observatories Origins Deep Survey (GOODS)-S and GOODS-N fields 50 .…”

“…JADES, a collaborative program between the NIRCam and NIRSpec Guaranteed Time Observations (GTO) instrument science teams, was designed to both discover high-redshift galaxies with NIRCam 33 and spectroscopically confirm them with NIRSpec 34 . Initial JADES NIRCam observations of the Great Observatories Origins Deep Survey -South (GOODS-S; 𝛼 = 53.165 deg, 𝛿 = −27.786 deg), including the Hubble Ultra Deep Field, were conducted starting September 29, 2022, under JWST programme 1180, acquiring NIRCam F090W, F115W, F150W, F200W, F277W, F335M, F356W, F410M, and F444W imaging (𝜆 ≈ 0.8 − 5 𝜇𝑚), covering an area of 65 arcmin 2 to a depth of 𝑓 !…”

Water‐Ice Dominated Spectra of Saturn's Rings and Small Moons From JWST

“…The infrared spectra of Saturn's rings and small moons have been well characterized thanks to extensive observations obtained by the Visual and Infrared Mapping Spectrometer (VIMS) and Composite Infrared Spectrometer (CIRS) onboard the Cassini spacecraft (R. H. Brown et al, 2004;Flasar et al, 2004). Observations of these objects with the instruments onboard JWST therefore provide opportunities not only to obtain new information about the rings and small moons themselves, but also to evaluate the performance of JWST's instruments, particularly the Integral Field Unit (IFU) components of NIRSpec and MIRI (Böker et al, 2022(Böker et al, , 2023Gardner et al, 2023;Jakobsen et al, 2022;Wright et al, 2023).…”