  The High altitude Water Cherenkov (HAWC) Observatory has been completed and
began full operation in early 2015. Located at an elevation of 4,100 m near the
Sierra Negra volcano in the state of Puebla, Mexico, HAWC consists of 300 water
tanks instrumented with 4 PMTs each. The array is optimized for detecting air
showers produced by gamma rays with energies between 100 GeV and 100 TeV and
can also be used to measure charged cosmic rays. A wide instantaneous field of
view of ~2 steradians and a duty cycle >95% allow HAWC to survey two-thirds of
the sky every day. These unique capabilities make it possible to monitor
variable gamma-ray fluxes and search for gamma-ray bursts and other transient
events, providing new insights into particle acceleration in galactic and
extra-galactic sources. In this contribution, we will present first results
from more than one year of observations with a partial array configuration. We
will discuss how HAWC can map the gamma-ray sky as well as probe other physics
including cosmic ray anisotropies and the search for signatures of dark matter
annihilation.
