Survey of radio recombination lines using the Ooty radio telescope at 328 MHz in the inner galaxy

Abstract

A survey of radio recombination lines in the Galactic plane with longitude -32° < l < +80° and latitude b < ±3° using Ooty Radio Telescope (ORT) at 328 MHz is reported. ORT observations were made using a New Digital Backend (NDB) recently added to the telescope. With the NDB ORT had a beam of 2fdg3 × 2fdg2 sec(δ) and a passband of ~1 MHz in the spectral line mode. The above-mentioned Galactic region was divided into ~2° × 2° patches with the ORT beam pointed to the center. The ORT observations form a study of the distribution of extended low-density warm-ionized medium (ELDWIM) in the inner Galaxy using H271α RLs. By obtaining kinematical distances using V LSR of the H271α RLs, the distribution of ELDWIM clouds within the inner Galaxy has been deduced for the region given above.