A sensitive 1.5 GHz radio survey around the north ecliptic pole

Ronald I. Kollgaard, Wolfgang Brinkmann, Margaret Mcmath Chester, Eric D. Feigelson, Paul Hertz, Patricia Reich, Richard Wielebinski

Research output: Contribution to journalReview articlepeer-review

33 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)145-159
Number of pages15
JournalAstrophysical Journal, Supplement Series
Issue number1
StatePublished - Jul 1994

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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