IRAC Point Spread Function

The four panels show the point spread function (PSF) in all four of the wavelength bands of the Infrared Array Camera (IRAC). The PSF in each panel is reconstructed from 108 images, each with a different pointing. By using an algorithm to combine the image, we have reconstructed the PSF on a finer scale. The displayed PSF images have pixels with 1/4 the size of the IRAC pixel (i.e. there are sixteen pixels for each IRAC pixel). The displayed x and y-axis scales are in IRAC pixels, each of which are 1.2" x 1.2" in size.
 
To reduce the contrast between the central core and the faint surrounding structure, the images are displayed with a square root scaling. Most of the light is in the central, white core of the PSF. As expected from diffraction, surrounding the core is the first Airy ring of the PSF. In the Channel 3 and 4 images, the ring is separated from the core. A fainter, second Airy ring is visible in the images.
 
IRAC was developed at the Smithsonian Astrophysical Observatory, with Giovanni Fazio as principal investigator, and was constructed at the Goddard Space Flight Center.

The Spitzer Space Telescope is a NASA mission managed by the Jet Propulsion Laboratory. This website is maintained by the Spitzer Science Center, located on the campus of the California Institute of Technology and part of NASA's Infrared Processing and Analysis Center. Privacy Policy