FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m
  telescope (FUGIN) I: Project Overview and Initial Results
  The FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m
telescope (FUGIN) project is one of the legacy projects using the new
multi-beam FOREST receiver installed on the Nobeyama 45-m telescope. This
project aims to investigate the distribution, kinematics, and physical
properties of both diffuse and dense molecular gas in the Galaxy at once by
observing 12CO, 13CO, and C18O J=1-0 lines simultaneously. The mapping regions
are a part of the 1st quadrant (10d < l < 50d, |b| < 1d) and the 3rd quadrant
(198d < l <236d, |b| < 1d) of the Galaxy, where spiral arms, bar structure, and
the molecular gas ring are included. This survey achieves the highest angular
resolution to date (~20") for the Galactic plane survey in the CO J=1-0 lines,
which makes it possible to find dense clumps located farther away than the
previous surveys. FUGIN will provide us with an invaluable dataset for
investigating the physics of the galactic interstellar medium (ISM),
particularly the evolution of interstellar gas covering galactic scale
structures to the internal structures of giant molecular clouds, such as small
filament/clump/core. We present an overview of the FUGIN project, observation
plan, and initial results, which reveal wide-field and detailed structures of
molecular clouds, such as entangled filaments that have not been obvious in
previous surveys, and large-scale kinematics of molecular gas such as spiral
arms.
