Search

We present the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1 Ma™ during the first and second observing runs of the advanced gravitational-wave detector network. During the first observing run (O1), from September 12, 2015 to January 19, 2016, gravitational waves from three binary black hole mergers were detected. The second observing run (O2), which ran from November 30, 2016 to August 25, 2017, saw the first detection of gravitational waves from a binary neutron star inspiral, in addition to the observation of gravitational waves from a total of seven binary black hole mergers, four of which we report here for the first time: GW170729, GW170809, GW170818, and GW170823. For all significant gravitational-wave events, we provide estimates of the source properties. The detected binary black holes have total masses between 18.6-0.7+3.2 Mâ™ and 84.4-11.1+15.8 Mâ™ and range in distance between 320-110+120 and 2840-1360+1400 Mpc. No neutron star-black hole mergers were detected. In addition to highly significant gravitational-wave events, we also provide a list of marginal event candidates with an estimated false-alarm rate less than 1 per 30 days. From these results over the first two observing runs, which include approximately one gravitational-wave detection per 15 days of data searched, we infer merger rates at the 90% confidence intervals of 110-3840 Gpc-3 y-1 for binary neutron stars and 9.7-101 Gpc-3 y-1 for binary black holes assuming fixed population distributions and determine a neutron star-black hole merger rate 90% upper limit of 610 Gpc-3 y-1. © 2019 authors. Published by the American Physical Society.

Single-frequency fiber amplifiers in MOPA configuration operating at 1064 nm (Yb3p) and around 1550 nm (Er3p or Er3p:Yb3p) are promising candidates to fulfill the challenging requirements of laser sources of the next generation of interferometric gravitational wave detectors (GWDs). Most probably, the next generation of GWDs is going to operate not only at 1064 nm but also at 1550 nm to cover a broader range of frequencies in which gravitational waves are detectable. We developed an engineering fiber amplifier prototype at 1064 nm emitting 215 W of linearly-polarized light in the TEM00 mode. The system consists of three modules: the seed source, the pre-amplifier, and the main amplifier. The modular design ensures reliable long-term operation, decreases system complexity and simplifies repairing and maintenance procedures. It also allows for the future integration of upgraded fiber amplifier systems without excessive downtimes. We also developed and characterized a fiber amplifier prototype at around 1550 nm that emits 100 W of linearly-polarized light in the TEM00 mode. This prototype uses an Er3p:Yb3p codoped fiber that is pumped off-resonant at 940 nm. The off-resonant pumping scheme improves the Yb3p-to-Er3p energy transfer and prevents excessive generation of Yb3p-ASE.

We present the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1 Ma™ during the first and second observing runs of the advanced gravitational-wave detector network. During the first observing run (O1), from September 12, 2015 to January 19, 2016, gravitational waves from three binary black hole mergers were detected. The second observing run (O2), which ran from November 30, 2016 to August 25, 2017, saw the first detection of gravitational waves from a binary neutron star inspiral, in addition to the observation of gravitational waves from a total of seven binary black hole mergers, four of which we report here for the first time: GW170729, GW170809, GW170818, and GW170823. For all significant gravitational-wave events, we provide estimates of the source properties. The detected binary black holes have total masses between 18.6-0.7+3.2 Mâ™ and 84.4-11.1+15.8 Mâ™ and range in distance between 320-110+120 and 2840-1360+1400 Mpc. No neutron star-black hole mergers were detected. In addition to highly significant gravitational-wave events, we also provide a list of marginal event candidates with an estimated false-alarm rate less than 1 per 30 days. From these results over the first two observing runs, which include approximately one gravitational-wave detection per 15 days of data searched, we infer merger rates at the 90% confidence intervals of 110-3840 Gpc-3 y-1 for binary neutron stars and 9.7-101 Gpc-3 y-1 for binary black holes assuming fixed population distributions and determine a neutron star-black hole merger rate 90% upper limit of 610 Gpc-3 y-1. © 2019 authors. Published by the American Physical Society.