• Public

  • Public
  • Network
  • Groups
  • Featured
  • Popular
  • People

What Can JWST Do? Provide an Uncrowded View! * NIR Crowding (from red giants) not a systematic (bias removed using artificial stars) but can be largest source of PL scatter (i.e., statistical noise). HST: Passed Six validation tests of backgrounds/crowding (Riess et al. 2022) Graphic titled “Uncrowding Cepheids in the Near-Infrared.” Left: Colorful image of a spiral galaxy is labeled “NGC 5584 (Webb NIRCam + Hubble WFC3).” Part of a spiral arm is outlined with a box. Inside the box is a solid red circle. Middle: Set of two diagrams illustrating zoomed-in views of the boxed region. Top diagram shows Hubble pointing toward a large transparent box. Long edge of the base is labeled “depth.” Box contains numerous overlapping, blue-green spheres of different sizes, with a red sphere near the middle. Bottom diagram shows Webb pointing toward an almost identical box. Spheres in this box are significantly smaller and there is less overlap. The red sphere is labeled “Cepheid.” Right: Two square grayscale images. Top is labeled “HST WFC3-IR.” Bottom labeled “JWST NIRCAM.” Pixels in the top image are noticeably larger than those in the bottom image. Black spots in the bottom image are smaller, more distinct, and more numerous.