Abstract
Positional, structural and dynamical parameters for all dwarf galaxies in and
around the Local Group are presented, and various aspects of our observational
understanding of this volume-limited sample are discussed. Over 100 nearby
galaxies that have distance estimates placing them within 3Mpc of the Sun are
identified. This distance threshold samples dwarfs in a large range of
environments, from the satellite systems of the MW and M31, to the dwarfs in
the outer regions of the Local Group, to the numerous isolated galaxies found
in its surroundings. It extends to, but does not include, the galaxies
associated with the next nearest groups. Our basic knowledge of this important
galactic subset and their resolved stellar populations will continue to improve
dramatically over the coming years with existing and future observational
capabilities, and they will continue to provide the most detailed information
available on numerous aspects of dwarf galaxy formation and evolution. Basic
observational parameters, such as distances, velocities, magnitudes, mean
metallicities, as well as structural and dynamical characteristics, are
collated, homogenized (as far as possible), and presented in tables that will
be continually updated to provide a convenient and current on-line resource. As
well as discussing the provenance of the tabulated values and uncertainties
affecting their usage, the membership and spatial extent of the MW and M31
subgroups and the Local Group are explored. The morphological diversity of the
entire sample and sub-groups is discussed, and time-scales are derived for the
Local Group members in the context of their orbital histories. The scaling
relations and mean stellar metallicity trends defined by the dwarfs are
presented, and the origin of a possible floor in central surface brightness
(and, more speculatively, stellar mean metallicity) at faint magnitudes is
considered.
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