Identification of cosmic γ-ray sources CG135+1 and CG189+1 with HII regions

ELEVEN unidentified γ-ray sources have been reported by the COS B group¹ one of which was previously known from the SAS 2 satellite². Here, I point out two likely associations of the new sources with giant HII regions. CG135+1 lies in the direction of the complex of HII regions, OB associations, molecular clouds and dust in the Cas OB6 region of the Perseus arm. An Hα photograph and identification chart for this region is given in ref. 3. The HII region W3 (IC1795) is located at (l = 133.7°, b = +1.1°), which is only 0.7° outside the one standard deviation error box for CG135+1 (l = 135.5° +/-1.0°, b = 1.5°+/-l.0°)¹. The SAS 2 longitude distribution⁴ is consistent with the existence of this source.