A survey of Radio Recombination Lines using Ooty Radio Telescope at 328 MHz in the Inner Galaxy

Abstract

A survey of radio recombination lines in the Galactic plane with longitude $-32^o < l < +80^o$ and latitude $b<\pm3^o$ using Ooty Radio Telescope(ORT) at 328 MHz has been reported. ORT observations were made using a New Digital Backend(NDB) augmented to it recently. With NDB ORT had a beam of $2^o.3 \times 2^o.2 sec(\delta)$ and a passband of $\sim$1 MHz in the spectral line mode. The above mentioned Galactic region was divided into $\sim 2^o \times 2^o$ patches with the ORT beam pointed to the center. The ORT observations form a study of distribution of extended low-density warm-ionized medium(ELDWIM) in the inner Galaxy using H271$\alpha$ RL. By obtaining kinematical distances using $V_{LSR}$ of the H271$\alpha$ RLs the distribution of ELDWIM clouds within the inner Galaxy has been deduced for the region given above.