  We present the first Open Gravitational-wave Catalog (1-OGC), obtained by
using the public data from Advanced LIGO's first observing run to search for
compact-object binary mergers. Our analysis is based on new methods that
improve the separation between signals and noise in matched-filter searches for
gravitational waves from the merger of compact objects. The three most
significant signals in our catalog correspond to the binary black hole mergers
GW150914, GW151226, and LVT151012. We assume a common population of binary
black holes for these three signals by defining a region of parameter space
that is consistent with these events. Under this assumption, we find that
LVT151012 has a 97.6\% probability of being astrophysical in origin. No other
significant binary black hole candidates are found, nor did we observe any
significant binary neutron star or neutron star--black hole candidates. We make
available our complete catalog of events, including the sub-threshold
population of candidates.
