H166α Emission as a Tracer of the Warped Ionized Gas Layer in the Northern Galaxy

Abstract

Observations of the H166 α recombination line were made with the 43 m antenna of the National Radio Astronomy Observatory (NRAO), in Green Bank, West Virginia, United States of America. The United States of results of the observations in the galactic longitude range 60−<l<90<− at each degree in galactic longitude and galactic latitudes b=0.0, b=+0.5−, b=+1.5−,b=−0.5− ,b=−1.5−, together with observations at l=81− and l=83− for b=−4− to b=+5−, each degree in galactic latitude, clearly show more recombination line emission for positive galactic latitudes than for negative galactic latitudes. We interpret these results as a clear evidence of the warp of the low density ionized gas layer towards positive latitudes in the Northern Galactic Plane.