Short gamma-ray bursts ( SGRBs ) observed by Swift are potentially revealing the first insight into cataclysmic compact object mergers .
To ultimately acquire a fundamental understanding of these events requires pan-spectral observations and knowledge of their spatial distribution to differentiate between proposed progenitor populations .
Up to April 2012 there are only some 30 \% of SGRBs with reasonably firm redshifts , and this sample is highly biased by the limited sensitivity of Swift to detect SGRBs .
We account for the dominant biases to calculate a realistic SGRB rate density out to z \approx 0.5 using the Swift sample of peak fluxes , redshifts , and those SGRBs with a beaming angle constraint from X-ray/optical observations .
We find an SGRB lower rate density of 8 ^ { +5 } _ { -3 } \mathrm { Gpc } ^ { -3 } \mathrm { yr } ^ { -1 } ( assuming isotropic emission ) , and a beaming corrected upper limit of 1100 ^ { +700 } _ { -470 } \mathrm { Gpc } ^ { -3 } \mathrm { yr } ^ { -1 } .
Assuming a significant fraction of binary neutron star mergers produce SGRBs , we calculate lower and upper detection rate limits of ( 1 - 180 ) yr ^ { -1 } by an aLIGO and Virgo coincidence search .
Our detection rate is similar to the lower and realistic rates inferred from extrapolations using Galactic pulsar observations and population synthesis .