GBT26A-476

Neutral Gas Content of Isolated Dwarf Galaxies in the Local Volume

Abstract

The neutral gas content in dwarf galaxies with 10^7 < M* < 10^9 Msun is well studied and shows a strong environmental dependence, highlighting environmental effects on regulating gas content and star formation. However, gas in lower-mass dwarfs (M* < 10^7 Msun) is poorly understood, especially for dwarf galaxies in the field. No existing HI survey covers the low-mass end and spans a wide range in star formation properties, making it difficult to characterize the full diversity of gas content. We propose deep GBT observations of 13 isolated dwarf galaxies with 10^6 < M* < 10^7 Msun in the Local Volume (<12 Mpc), selected from optical surveys covering 3000 deg???????. These targets, including both star-forming and quenched systems, lack HI detections in existing surveys (ALFALFA, HIPASS, FASHI). Our observations will improve current HI mass limits by over an order of magnitude, reaching M_HI/M* = 0.1. This will complete the first systematic, unbiased census of HI content in field dwarfs in the low-mass regime. Combined with multi-wavelength data from UV to HI, we will directly measure the quenched fraction at M* < 10^7 Msun for the first time, investigate rare quenched field dwarfs, and understand the importance of different quenching mechanisms.

Investigators

Name	Institution
Jiaxuan Li *	Princeton University
Scott Carlsten	Princeton University
Jenny Greene	Princeton University
Jingyao Zhu	Columbia University
Shany Danieli	Tel Aviv University

* indicates the PI