Sky background accounting in spectral infrared observations of extended objects at the Caucasus Mountain Observatory of the SAI MSU

Abstract

The Caucasus Mountain Observatory of the Sternberg Astronomical Institute of Moscow State University is the only one in Russia and one of the few in the world where is possible to obtain spectral data in the near-infrared (IR) range at $\lambda$=1-2.5 $\mu$m. However, there is a problem of processing the spectra of extended objects, the angular dimensions of which exceed the length of the slit (4.5 arcmin). Obtaining additional spectra of the sky in the immediate vicinity of such objects does not solve the problem, since bright atmospheric hydroxyl lines at $\lambda$~2 $\mu$m change their intensity significantly over a time shorter than the exposure time of a single frame. We have developed a technique that allows us to correctly account for and exclude the contribution of variable atmospheric lines in the spectra of extended objects. This technique has been successfully tested in spectroscopic studies of the star-forming region NGC 7538 (S158) in our Galaxy.

14 pages, 8 figures. Accepted for publication in Moscow University Physics Bulletin

References in corpus (5)

• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope I. Overview of the instrument and its capabilities
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope III. Integral-field spectroscopy
• ASTRONIRCAM - infrared camera-spectrograph for Sternberg institute 2.5 METER TELESCOPE
• Near infrared view on the photodissociation regions S255, S257, NGC7538 and S140
• OPTIMus-Survey of massive star-forming regions at OPTical, Infrared, and Millimeter wavelengths