GBT25B-208

LOW SURFACE BRIGHTNESS NEUTRAL HI GAS CONTENT OF HIMALAYA GALAXIES

Abstract

The extended H I disk around galaxies serves as a major gas reservoir, continuously supplying fuel for star formation. The HI observations of MAssive gaLAxies to studY cold gAs (HIMALAYA) project aims to investigate large-scale diffuse H I gas in spiral disk galaxies and its role in galaxy evolution. So far, our obtained deep VLA H I observations of HIMALAYA galaxies have allowed us to probe the dense, star-forming regions of galaxies. However, due to the u-v short-spacing problem inherent in interferometric observations, these data miss the large-scale, low-surface-brightness diffuse H I gas. To address this, we propose 38.5 hours of GBT observations to complement the VLA data by capturing the potential missing extended H I structures in 14 high rotation velocity spiral disk galaxies. These observations will enable us to detect large-scale H I features extending over a significant fraction of the dark matter halo. Combined with multi-wavelength data, we will derive the global mass and map the distribution of cold H I gas, quantify the baryon budget across different CGM phases as well as diffuse H~I fraction. This study will provide new insights into gas accretion processes from the CGM and their impact on galaxy evolution.

Investigators

Name	Institution
Yang Yang *	Purple Mountain Observatory, CAS; Shanghai Astronomical Observatory, CAS; Nanjing University
Jiangtao Li	Michigan at Ann Arbor, University of; Purple Mountain Observatory, CAS
Lorant Sjouwerman	National Radio Astronomy Observatory
Wei Sun	Purple Mountain Observatory, CAS

* indicates the PI