A 29.3 deg2 region surrounding the north ecliptic pole (NEP; α = 18h00m, δ = +66°30′) was mapped with the Very Large Array at 1.5 GHz to support the deepest portion of the ROSAT all-sky soft X-ray survey. The resulting VLA-NEP survey catalog contains 2435 radio sources with flux densities in the range of 0.3-1000 mJy, including over 200 fainter than 1 mJy. The 28 fields of the inner 1°.5 have noise levels σ ≈ 60 μJy, and the 85 fields centered between 1°.5 and 3°.0 from the NEP have σ ≈ 120 μJy. The typical spatial resolution is 20″ HPBW, and most positions are accurate to <2″. Approximately 6% of the sources are found to be extended with size >30″. We have compared the VLA-NEP catalog with four other radio catalogs made at lower resolution, as well as with the NASA Extragalactic Database and find counterparts for ∼18% of the VLA-NEP objects. The normalized, differential radio source count is in agreement with previous studies. Between 1 and 150 mJy the slope of the log N-log S relation is 0.68 ± 0.03. The catalog and related tables are available electronically.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science