Survey of Galactic HI Emission At ∣b∣ ≤ 20°

Abstract

We have used the NRAO 140-ft telescope to survey galactic HI near the galactic equator. The observations cover the part of the sky north of δ = −40° in the latitude range b = −20° to at least +20°; in some regions the survey extends to b = +33°. The longitude coverage in the equator ranges from l = 340° to 270°. The data represent an improvement over existing large-scale HI surveys in terms of velocity coverage \(\left( { \pm 250\,km\,{s^{ - 1}}} \right) \), velocity resolution (1 km s−1), sensitivity (3σ =0.2 K), and extent of sky coverage, but not in density (Δl × Δb = 1° × 1°) of coverage.