Survey of Galactic HI emission at |b| ≤ 20°

Extract

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 (±250 km s⁻³), 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.