A Map of the Northern Sky at 10 MHz

Abstract

The Penticton 10-MHz T-shaped array has been used to map a large portion of the sky north of dec – 5°; the beamwidth at the zenith is approximately 2°. The map includes a portion of the galactic plane, the high-latitude region of minimum sky brightness and part of the north galactic spur. Comparisons are made with surveys at higher radio frequencies and with optically observed H II regions of large angular size; most of these H II regions give rise to prominent absorption features on the map, and these are discussed in detail. A new estimate of the mean value of the emissivity of galactic non-thermal radiation has been derived and most of the emission is shown to be confined to the spiral arms, with much lower emission present in the interarm region.