The influence of angular momentum and environment on the H i gas of late-type galaxies

We use high-resolution H I data from the Westerbork H I Survey of Spiral and Irregular Galaxies (WHISP) to study the H I and angular momentum properties of a sample of 114 latetype galaxies. We explore the specific baryonic angular momentuma-baryonic mass (j_ba-M_b)relation, and find that an unbroken power law of the form j_b∝ M^0.55±0.02_bfits the data well, with an intrinsic scatter of ∼0.13 ± 0.01 dex. We revisit the relation between the atomic gas fraction, f_atm, and the integrated atomic stability parameter q (the f_atma-q relation), originally introduced by Obreschkow et al., and probe this parameter space by populating it with galaxies from different environments, in order to study the influence of the environment on their j_b, f_atm, and q values. We find evidence that galaxies with close neighbours show a larger intrinsic scatter about the f_atma-q relation compared to galaxies without close neighbours. We also find enhanced star formation rate among the deviating galaxies with close neighbours. In addition, we use the bulge-to-total (B/T) ratio as a morphology proxy, and find a general trend of decreasing B/T values with increasing disc stability and H I fraction in the f_atma-q plane, indicating a fundamental link between mass, specific angular momentum, gas fraction, and morphology of galaxies.