The Infrared Spectrograph (IRS) on the <i>Spitzer Space Telescope</i>

TLDR

The Infrared Spectrograph on the Spitzer Space Telescope covers 5.3–38 µm with R ≈ 90–600 and is optimized for the low‑background space environment. It employs autonomous target acquisition to locate a source’s mid‑infrared centroid and an automated pipeline at the Spitzer Science Center for data reduction. The IRS meets or exceeds pre‑launch performance predictions, and its acquisition capability improves spectroscopy of sources with poorly known coordinates.

Abstract

The Infrared Spectrograph (IRS) is one of three science instruments on the Spitzer Space Telescope. The IRS comprises four separate spectrograph modules covering the wavelength range from 5.3 to 38micron with spectral resolutions, R \~90 and 600, and it was optimized to take full advantage of the very low background in the space environment. The IRS is performing at or better than the pre-launch predictions. An autonomous target acquisition capability enables the IRS to locate the mid-infrared centroid of a source, providing the information so that the spacecraft can accurately offset that centroid to a selected slit. This feature is particularly useful when taking spectra of sources with poorly known coordinates. An automated data reduction pipeline has been developed at the Spitzer Science Center.