Radial Motions and Radial Gas Flows in Local Spiral Galaxies

We determine radial velocities and mass flow rates in a sample of 54 local spiral galaxies by modelling high-resolution high-sensitivity data the atomic hydrogen emission line. found that, although inflow motions seem to be slightly preferred over outflow motions, their magnitude is generally small. Most show flows only few km/s throughout HI disks, either inwards or outwards, without any clear increase outermost regions, as we would expect for continuous accretion. Gas most are less than 1 M$_\odot$/yr. Over entire sample, estimated an average rate 0.3 M$_\odot$/yr outside optical disk 0.1 outskirts disks. These about 5-10 times smaller star formation 1.4 Our study suggests that there no evidence systematic accretion inflows alone could feed sustain process inner regions at its current rate.