Presentation #325.04 in the session “Data Handling”.
Slitless spectroscopy is an astronomical observation technique designed to capture multiple spectra at once by dispersing the light from all objects in the field. In principle, slitless spectroscopy is a powerful survey and discovery tool, especially for space-based application. On the ground, however, slitless spectroscopy is limited because the brightness of the sky background is integrated over the full bandpass. This results in spectra with significantly lower signal-to-noise ratios (SNR) than those taken in conventional slit mode. However, it is now possible to produce custom-built multi-band filters that reject specific bandpasses. In this project, we have studied the performance of slitless spectroscopy with a multi-band filter that rejects the spectral region more heavily hampered by the telluric sky emission in the visible. The resulting spectra show gaps in the spectral coverage, especially above 600nm, but this is compensated by a general increase in SNR. Rebinning the spectra further increases the SNR, resulting in an observing technique that may be competitive and more versatile than with other imaging such as multi-band sequential imaging. We quantitatively estimate the advantages of multi-band filters with slitless spectroscopy through simulations of spectra captured with the SAMOS instrument under construction for the SOAR telescope.