In collaboration with the international colleagues, scientists at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute; AEI), have published their second Open Gravitational-wave Catalog (2-OGC). Scientists used search methods to get detailed insights from LIGO’s and Virgo’s first and second observation runs.
Aside from affirming the ten known binary black hole mergers and one binary neutron star merger, they also distinguish four promising black hole gap merger candidates, which were missed by starting LIGO/Virgo analysis. These outcomes exhibit the value of searches in public LIGO/Virgo data by research groups independent of the LIGO/Virgo collaborations. The examination group additionally makes accessible its complete catalog in addition to a detailed analysis of more than a dozen possible binary black hole mergers.
Alexander Nitz, a staff scientist at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Hannover, who led the international research team, said, “We incorporate cutting edge methods. Our improvements enable discovering fainter binary black hole mergers: the four additional signals show that this works!”
The work led by Nitz affirms 14 of these events and finds one more possible binary black hole merger missed by previous analysis. Assuming genuine, GW151205 originated from a somewhat distant merger of two massive black holes of about 70 and 40 times the mass of our Sun, separately.
Collin Capano, a senior researcher at the AEI Hannover, said, “The trick was not only an improved way of ranking potential gravitational-wave signals but also to target the properties that binary black holes are expected to have. Our sensitivity to binary black holes is improved by 50% to 60% by using this information to tune our search to look for the most likely signals. We have an idea of what the typical mass is of a binary black hole from the signals that were already detected. Our sensitivity to binary black holes is improved by 50% to 60% by using this information to tune our search to look for the most likely signals.”
However, scientists didn’t detect new candidates for binary neutron star mergers in LIGO/Virgo data from O1 and O2. Because only two binary neutron star mergers have been identified by their gravitational waves and the underlying population is not well-known, a targeted search is not yet possible.
Sumit Kumar, a senior researcher at the AEI Hannover said, “The 15 signals reported now are only a small part of a larger online catalog. The team published its complete catalog of events, including statistically less significant candidates and the detailed results of their analysis. We hope that these data will enable other researchers to conduct future in-depth searches by providing a better understanding of the binary black hole population, as well as background noise.”
The results were published in The Astrophysical Journal today.