Timothy D. Rawle

The JWST Extragalactic Mock Catalog: Modeling Galaxy Populations from the UV through the Near-IR over 13 Billion Years of Cosmic History

We present an original phenomenological model to describe the evolution of galaxy number counts, morphologies, and spectral energy distributions across a wide range of redshifts (

The JWST/NIRSpec exoplanet exposure time calculator

0.2\lt z\lt 15

Preparing the NIRSpec/JWST science data calibration: from ground testing to sky

) and stellar masses

The contrast performance of the NIRSpec micro shutters and its impact on NIRSpec integral field observations

[\mathrm{log}(M/{M}_{\odot })\geqslant 6]

JWST’s near infrared spectrograph status and first OTIS test results

. Our model follows observed mass and luminosity functions of both star-forming and quiescent galaxies, and reproduces the redshift evolution of colors, sizes, star formation, and chemical properties of the observed galaxy population. Unlike other existing approaches, our model includes a self-consistent treatment of stellar and photoionized gas emission and dust attenuation based on the beagle tool. The mock galaxy catalogs generated with our new model can be used to simulate and optimize extragalactic surveys with future facilities such as the James Webb Space Telescope (JWST), and to enable critical assessments of analysis procedures, interpretation tools, and measurement systematics for both photometric and spectroscopic data. As a first application of this work, we make predictions for the upcoming JWST Advanced Deep Extragalactic Survey (JADES), a joint program of the JWST/NIRCam and NIRSpec Guaranteed Time Observations teams. We show that JADES will detect, with NIRCam imaging, 1000s of galaxies at z gsim 6, and 10s at z gsim 10 at

Operability assessment concept for the JWST/NIRSpec micro-shutter array (MSA)

{m}_{{AB}}\lesssim 30

Simulating and interpreting deep observations in the Hubble Ultra Deep Field with the JWST/NIRSpec low-resolution ‘prism’

(5σ) within the 236 arcmin2 of the survey. The JADES data will enable accurate constraints on the evolution of the UV luminosity function at z > 8, and resolve the current debate about the rate of evolution of galaxies at z gsim 8. Ready-to-use mock catalogs and software to generate new realizations are publicly available as the JAdes extraGalactic Ultradeep Artificial Realizations (JAGUAR) package.

Noise performance of the JWST/NIRSpec detector system

The James Webb Space Telescope (JWST), with its unprecedented sensitivity, will provide a unique set of tools for the study of transiting exoplanets and their atmospheres. The Near Infrared Spectrograph (NIRSpec) is one of four scientific instruments on JWST and offers a high-contrast aperture-spectroscopy mode developed specifically for exoplanet observations. Here we present the NIRSpec Exoplanet Exposure Time Calculator (NEETC) software, an exposure time calculator optimized to evaluate the signal-to-noise ratio and simulate spectra for observations of transiting exoplanets. The NEETC is being developed to help the NIRSpec instrument team, and ultimately future JWST users, to fully investigate NIRSpec’s observation modes and the feasibility of exoplanet observations. We give examples of how the NEETC can be used to prepare observations, and present results highlighting the capabilities and limitations of NIRSpec.

Flat-fielding strategy for the JWST/NIRSpec multi-object spectrograph

The Near-Infrared Spectrograph (NIRSpec) is one of four instruments aboard the James Webb Space Telescope (JWST). NIRSpec is developed by ESA with AIRBUS Defence & Space as prime contractor. The calibration of its various observing modes is a fundamental step to achieve the mission science goals and provide users with the best quality data from early on in the mission. Extensive testing of NIRSpec on the ground, aided by a detailed model of the instrument, allow us to derive initial corrections for the foreseeable calibrations. We present a snapshot of the current calibration scheme that will be revisited once JWST is in orbit.

In-orbit commissioning of the NIRSpec instrument on the James Webb Space Telescope

The Near Infrared Spectrograph (NIRSpec) instrument is one of the four scientific instruments aboard the James Webb Space Telescope (JWST). NIRSpec can be operated in Multi-Object Spectroscopy (MOS), Fixed-slit Spectroscopy (FS), and Integral Field Spectroscopy (IFS) modes; with spectral resolutions from 100 to 2700. Two of these modes, MOS and IFS, share the same detector real estate and are mutually exclusive. Consequently, the micro-shutters used to select targets in MOS mode must all be closed when observing in IFS mode. However, due to the finite contrast of the micro-shutter array (MSA), some amount of light passes through them even when they are commanded closed. This light creates a low, but potentially significant, parasitic signal, which can affect IFS observations. Here, we present the work carried out to study and model this signal. Firstly, we show the results of an analysis to quantify its levels for all NIRSpec spectral bands and resolution powers. We find a level of parasitic signal that is, in general, lower than 10% of the incident, extended IFS signal. We also show how these results were combined with signal-to-noise considerations to help consolidate the observation strategy for the IFS mode and to prepare guidelines for designing observations. In general, we find that this parasitic signal will be less than the statistical noise of a Zodiacal light exposure up to ~40 groups for the NIRSpec grating configurations, and ~10 groups for the prism configuration. In a second part, we report on the results of our work to model and subtract this signal. We describe the model itself, its derivation, and its accuracy as determined by applying it to ground test data.