The Low-Resolution DRAO Survey of H [CSC]i[/CSC] Emission from the Galactic Plane

Abstract

A survey of H I line emission in the Galactic plane from Galactic longitude l = 722 to 149 0, and latitude b = -54 to 72, has been made using the 26-m Telescope at the Dominion Radio Astrophysical Observatory. Spectra were observed at 02 intervals of longitude and latitude, providing a survey which is fully sampled in the spatial domain. A detailed study of the antenna characteristics of the telescope allowed the correction of the spectra for stray radiation. The spectral resolution is 1.32 km s-1, and the LSR velocity range is -260 to 161 km s-1. The final spectra have an estimated Tb scaling accuracy of 1% and an estimated rms noise in one channel (0.8245 km s-1) of 0.25 K. A region of suspected strong H I self-absorption at l ∼ 92°, b ∼ 3°, has been identified. Comparison with spectra from the Leiden/Dwingeloo Survey is used to estimate the overall accuracy of the stray radiation corrections. This comparison also shows that a small percentage (∼1%) of the spectra in the latter survey suffer from calibration errors exceeding 10%. A table of positions of the more discordant spectra is given.