GBT26A-120

GBT Diffuse Ionized Gas Survey at Low frequencies -- GDIGS-Low

Abstract

This proposal aims to continue the GBT Diffuse Ionized Gas Survey at Low frequencies (GDIGS-Low). GDIGS-Low is mapping the inner galaxy (-5<l<32 deg |b|<1 deg) in hydrogen radio recombination lines (HRRLs) at 340 and 800 MHz to determine the properties of the dense warm ionized medium (D-WIM) in the Galactic plane. Through this survey we will answer the following questions (i) What are the physical properties of the D-WIM?, (ii) How are the physical properties of the D-WIM affected by radiative feedback?, (iii) What is the relationship between the D-WIM and HII regions?, and (iv) Are O stars the primary source of ionization for the D-WIM? Answering these questions will be possible using multi-frequency HRRLs at 340, 800 and 5000 MHz, from which changes in the line intensity allow for gas density and path lengths to be determined. The 5 GHz observations come from the successful GBT survey, GDIGS.

This proposal requests to complete the 340 MHz portion of the survey, as this receiver was not offered during the previous proposal call.

Investigators

Name	Institution
Pedro Salas *	Green Bank Observatory
Kimberly Emig	National Radio Astronomy Observatory
Anish Roshi	Florida, University of Central
Loren Anderson	West Virginia University
Dylan Linville	West Virginia University
Poojapriyatharsheni Jeyasingh	Lady Doak College
Leonardo Supan	Instituto de Astronomía y Física del Espacio
Trey Wenger
Matteo Luisi	Westminster College
Allison Smith	National Astronomy and Ionosphere Center ; Georgia, University of
Mayumi Sato	Bielefeld, Universität

* indicates the PI