100 Proof: HI Observations of 100 Nearby Dwarf Galaxies with the 100-meter Green Bank Telescope

TL;DR

This study presents HI observations of 105 nearby dwarf galaxies using the Green Bank Telescope, revealing their gas properties, velocities, and potential satellite status, with most being gas-rich and following the Tully-Fisher relation.

Contribution

First comprehensive HI survey of recently discovered dwarf galaxies, including new satellites, with detailed analysis of their gas content and kinematic properties.

Findings

77 out of 105 galaxies detected in HI

Most galaxies are gas-rich with median gas-to-stellar-mass ratio of 1.87

Detected galaxies follow the Tully-Fisher relation for disk galaxies

Abstract

We describe the results of observations with the 100m Robert C. Byrd Green Bank Telescope (GBT) in the HI line of 105 nearby dwarf galaxies, 60 of which were discovered recently in the DESI Legacy Imaging Surveys. Of 105 objects observed, we detected 77 galaxies with the following median parameters: an HI-flux of 0.69 Jy km/s, a heliocentric velocity of 732 km/s, and a $W_{50}$ line width of 32 km/s. 70 are isolated late-type objects and 35 are new probable satellites of nearby spiral galaxies (NGC 628, NGC 2787, NGC 3556, NGC 4490, NGC 4594 and NGC 5055). The detected galaxies are predominantly gas-rich systems with a median gas-to-stellar-mass ratio of 1.87. In general, they follow the classic Tully-Fisher relation obtained for large disk-dominated spiral galaxies if their $M_{21}$ magnitudes are used instead of B-magnitudes.