Mapping the extended H i distribution of three dwarf galaxies

Abstract

We present large field H I-line emission maps obtained with the single-dish Green Bank Telescope centered on the dwarf irregular galaxies Sextans A, NGC 2366, and WLM. We do not detect the extended skirts of emission associated with the galaxies that were reported from Effelsberg observations. The ratio of H I at 1019 atomscm-2 to optical extents of these galaxies is instead 2-3, which is normal for this type of galaxy. There is no evidence for a truncation in the H I distribution ≥1019 atomscm-2. © 2011. The American Astronomical Society. All rights reserved.