The NIRCam science objectives are the detection and identification of "first light" objects, the study of star and brown dwarf formation, and the detection and characterization of planetary systems and their formation. These three science programs are also the key objectives of the JWST program as a whole. The NIRCam instrument design is optimized for these objectives within the mission constraints. NIRCam consists of two optics modules, each with a field of view of 2.2 arcmin square. The modules are identical except for the mechanical layout. Each module consists of two channels divided by a dichroic beamsplitter. The short wavelength channel has a band pass of 0.6 - 2.3 microns, with pixels sized for Nyquist sampling of the PSF at 2.0 microns. The long wavelength channel has a band pass of 2.4 - 5.0 microns, with pixels sized for Nyquist sampling at 4.0 microns. Selections of wide (R~4), intermediate (R~10), and narrow (R~100) bandwidth filters are provided in each of the four channels, along with coronagraphic occulting masks and pupil stops. A refractive optical design results in a smaller instrument volume and mass, provides good images at the pupils for wavefront sensing and coronagraphy, allows good access to the pupils and focal planes, and relaxes the alignment requirements compared to a reflective design. The NIRCam instrument is funded by NASA/GSFC under contract NAS5-02105.

The Near-Infrared Camera (NIRCam) for the James Webb Space Telescope (JWST)

Transverse translation diversity phase retrieval (TTDPR) is an image-based wavefront sensing technique where a mask with a known transmission distribution translates through a pupil plane of the system under test while point spread functions are acquired. Usually this requires knowledge of the translation of the mask, knowledge of the pupil illumination due to the system’s aperture stop and a target that does not move between frames. We demonstrate, by Monte-Carlo simulation, a multi-stage bootstrapping technique capable of estimating pupil phase with hundredth wave RMS error even when all of these requirements are unmet.

Transverse translation diversity wavefront sensing with limited position and pupil illumination knowledge

The James Webb Space Telescope (JWST) will revolutionize the field of high-contrast imaging and enable both the direct detection of Saturn-mass planets and the characterization of substellar companions in the mid-infrared. While JWST will feature unprecedented sensitivity, angular resolution will be the key factor when competing with ground-based telescopes. Here, we aim to characterize the performance of several extreme angular resolution imaging techniques available with JWST in the 3–5 µm regime based on data taken during the instrument commissioning. Firstly, we introduce custom tools to simulate, reduce, and analyze JWST NIRCam and MIRI coronagraphy data and use these tools to extract companion detection limits from on-sky NIRCam round and bar mask coronagraphy observations. Secondly, we present on-sky JWST NIRISS aperture masking interferometry (AMI) and kernel phase imaging (KPI) observations from which we extract companion detection limits using the publicly available fouriever tool. Scaled to a total integration time of one hour and a target of the brightness of AB Dor (W1 ≈ 4.4 mag, W2 ≈ 3.9 mag), we find that NIRISS AMI and KPI reach contrasts of ∼ 7–8 mag at ∼ 70 mas and ∼ 9 mag at ∼ 200 mas. Beyond ∼ 250 mas, NIRCam coronagraphy reaches deeper contrasts of ∼ 13 mag at ∼ 500 mas and ∼ 15 mag at ∼ 2 arcsec. While the bar mask performs ∼ 1 mag better than the round mask at small angular separations ≲ 0.75 arcsec, it is the other way around at large angular separations ≳ 1.5 arcsec. Moreover, the round mask gives access to the full 360 deg field-of-view which is beneficial for the search of new companions. We conclude that already during the instrument commissioning, JWST high-contrast imaging in the L- and M-bands performs close to its predicted limits and is a factor of ∼ 10 times better at large separations than the best ground-based instruments operating at similar wavelengths despite its < 2 times smaller collecting area.

/pdf/performance-of-near-infrared-high-contrast-imaging-methods-m1bnjyxp.pdf

Performance of near-infrared high-contrast imaging methods with JWST from commissioning

The NIRCam instrument on the James Webb Space Telescope (JWST) will provide a coronagraphic imaging capability to search for extrasolar planets in the 2 – 5 microns wavelength range. This capability is realized by a set of Lyot pupil stops with patterns matching the occulting mask located in the JWST intermediate focal plane in the NIRCam optical system. The complex patterns with transparent apertures are made by photolithographic process using a metal coating in the opaque region. The optical density needs to be high for the opaque region, and transmission needs to be high at the aperture. In addition, the Lyot stop needs to operate under cryogenic conditions. We will report on the Lyot stop design, fabrication and testing in this paper.

/pdf/nircam-coronagraphic-lyot-stop-design-fabrication-and-3n5nov67oc.pdf

NIRCam coronagraphic Lyot stop: design, fabrication, and testing

Popular Tasks used by Researchers

How can I help with your research?

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

We encountered an error while loading the panel. Please try refreshing the page.

Something went wrong

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

Anyone with the link can view this chat. You can switch it back to private anytime.

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Carmen Barone

Author Tools

Chat about Author

Papers

NIRCam coronagraphic Lyot stop: design, fabrication, and testing