HVC/IVC Maps and HVC Distribution Functions

Abstract

This chapter presents an overview of the basic sky, velocity, column density, volume density, area, and flux distributions of the high-velocity clouds (HVCs). All-sky maps are shown of their deviation and GSR velocities, and their column densities. A comparison is made between the HVCs defined by using a limit in the deviation velocity (logically preferred) versus using a limit in the LSR velocity (historically done). A comparison is also made between the HVC maps obtained using the Leiden- Dwingeloo Survey (Hartmann \& Burton 1997) versus the maps obtained with the combined Hulsbosch \& Wakker (1988) and Morras et al. (2000) surveys. The maps of the negative-velocity HVCs and IVCs in the northern galactic hemisphere are compared and it is shown that they are probably unrelated.