GBT26B-313

Probing Extreme Gas Depletion in MW-like Environments

Abstract

We propose to deepen the HI sensitivity limits for 33 star-forming satellite galaxies from the SAGA Survey previously observed with the GBT in 24B and 25B. Our earlier observations reached typical sensitivities of ~1.8 mJy, sufficient for robust detections in gas-rich systems, but not for fully characterizing the low gas-fraction tail of the population. By combining existing integrations with new observations in 26B, we request 66 hours to reach a uniform sensitivity of 0.7 mJy for this subsample.
Achieving this depth will allow us to identify or tightly constrain some of the lowest gas-fraction star-forming satellites known beyond the Local Volume, placing the extremely gas-poor satellites of the Milky Way into a broader cosmological context.
These observations will quantify the extent to which satellites can maintain star formation despite strong gas depletion, and provide new constraints on possible environmental quenching pathways in MW-like halos.

Investigators

Name	Institution
GBT Operator	Green Bank Observatory
Yasmeen Asali *	Yale University
Marla Geha	Yale University

* indicates the PI