We report here the non-detection of gravitational waves from the merger of binary neutron star systems and neutron-star–black-hole systems during the first observing run of Advanced LIGO .
In particular we searched for gravitational wave signals from binary neutron star systems with component masses \in [ 1 , 3 ] M _ { \odot } and component dimensionless spins < 0.05 .
We also searched for neutron-star–black-hole systems with the same neutron star parameters , black hole mass \in [ 2 , 99 ] M _ { \odot } and no restriction on the black hole spin magnitude .
We assess the sensitivity of the two LIGO detectors to these systems , and find that they could have detected the merger of binary neutron star systems with component mass distributions of 1.35 \pm 0.13 M _ { \odot } at a volume-weighted average distance of \sim 70 \mathrm { Mpc } , and for neutron-star–black-hole systems with neutron star masses of 1.4 M _ { \odot } and black hole masses of at least 5 M _ { \odot } , a volume-weighted average distance of at least \sim 110 \mathrm { Mpc } .
From this we constrain with 90 % confidence the merger rate to be less than 12,600 Gpc ^ { -3 } yr ^ { -1 } for binary-neutron star systems and less than 3,600 Gpc ^ { -3 } yr ^ { -1 } for neutron-star–black-hole systems .
We discuss the astrophysical implications of these results , which we find to be in tension with only the most optimistic predictions .
However , we find that if no detection of neutron-star binary mergers is made in the next two Advanced LIGO and Advanced Virgo observing runs we would place significant constraints on the merger rates .
Finally , assuming a rate of 10 ^ { +20 } _ { -7 } Gpc ^ { -3 } yr ^ { -1 } short gamma ray bursts beamed towards the Earth and assuming that all short gamma-ray bursts have binary-neutron-star ( neutron-star–black-hole ) progenitors we can use our 90 % confidence rate upper limits to constrain the beaming angle of the gamma-ray burst to be greater than { 2.3 ^ { +1.7 } _ { -1.1 } } ^ { \circ } ( { 4.3 ^ { +3.1 } _ { -1.9 } } ^ { \circ } ) .