From Rochester Institute of Technology and LIGO Scientific Collaboration: “LIGO and Virgo announce 39 new gravitational wave discoveries during first half of third observing run”

From Rochester Institute of Technology


LSC LIGO Scientific Collaboration

LIGO Scientific Collaboration

October 29, 2020
Luke Auburn

RIT scientists helped analyze and interpret the ripples in space and time.

Masses in the Stellar Graveyard 9-2-20. GWTC-2 plot v1.0 BY LIGO-Virgo Frank Elavsky and Aaron Geller at Northwestern University.

Masses in the Stellar Graveyard GWTC-2 plot v1.0 BY LIGO-Virgo Frank Elavsky and Aaron Geller at Northwestern University.

The LIGO Scientific Collaboration and Virgo Collaboration released a catalog of results from the first half of its third observing run (O3a). This shows the masses of the black holes and neutron stars in the 50 gravitational wave events detected to date.

Scientists have detected more than three times as many gravitational waves than the first two runs combined. Gravitational waves were first detected in 2015 and are ripples in time and space produced by merging black holes and/or neutron stars. Several researchers from Rochester Institute of Technology’s Center for Computational Relativity and Gravitation (CCRG) were heavily involved in analyzing the gravitational waves and understanding their significance.

Localizations of gravitational-wave signals detected by LIGO in 2015 (GW150914, LVT151012, GW151226, GW170104), more recently, by the LIGO-Virgo network (GW170814, GW170817). After Virgo (IT) came online in August 2018.

The catalog details 39 new gravitational wave events detected during O3a, bringing the total to 50, and several of the newly detected binaries have unique properties that expand our understanding of binary black hole formation. O3a uncovered the largest and smallest binary black holes to date, ranging from 150 times the size of our sun to just 3 times larger. O3a also detected the first binary black hole confidently formed from highly asymmetrical black holes as well as several binary black holes with unique spin properties.

Jacob Lange ’18 MS (astrophysical sciences and technology), ’20 Ph.D. (astrophysical sciences and technology) worked on the parameter estimation part of the analysis, which identifies important characteristics about each gravitational wave event, including the masses of the black holes or neutron stars involved, their spin, distance from Earth and position in the sky. While he was a Ph.D. student at RIT, he helped develop parameter estimation algorithms that were faster than conventional methods and used for many of the events released in the catalog. Lange, who is now a postdoctoral researcher at Brown University’s Institute for Computational and Experimental Research in Mathematics, said that improvements to the sensors and parameter estimation techniques have yielded increasingly unique findings that challenge our understanding of the universe.

“We’re seeing much more complex events where nature’s really showing us its fascinating side,” said Lange. “We’ll be able to learn much more interesting physics and astrophysics from these detections. The more we build up this catalog of events, the more we can start making statements about the overall population.”

Daniel Wysocki ’18 MS (astrophysical sciences and technology), ’20 Ph.D. (astrophysical sciences and technology) worked on analyzing the population properties of black holes following O3a. Wysocki, now a postdoctoral researcher at University of Wisconsin–Milwaukee, said that we are gaining a clearer picture about what typical black holes look like, how many exist, how the population of black holes has changed as the universe evolved, and other important properties.

“This catalog represents a significant increase in sample size from our previous release,” said Wysocki. “It’s like a census that provides data for people to see if their physical models are consistent with what happens in the universe. This has implications for general relativity, the physics of stars, and the behavior of matter at energies that aren’t possible in a terrestrial laboratory. Down the line that can really help us change our understanding of things on Earth.”

With incremental improvements coming online in the next several years, new ground and space observatories in the coming decades, and LIGO and Virgo preparing for the fourth observing run, the future is bright for gravitational wave astronomy. Associate Professor Richard O’Shaughnessy, a member of CCRG and the LIGO Scientific Collaboration, said even more discoveries are on the horizon.

“We’ve learned more about what nature permits,” said O’Shaughnessy. “We found more big black holes, smaller siblings of the massive event described in the summer and we found, too, that large black holes can be rapidly spinning. That breaks some theories for how large black holes could form. We see very tantalizing suggestions that some of the merging black holes may have spins misaligned with the orbit.”

Speculating about the significance of these observations, O’Shaughnessy said, “Many years ago, I showed that misalignment could clearly identify how merging black holes came to be. We’re one step closer to finding a smoking gun.”

For more information about O3a, visit the LIGO Scientific Collaboration website.

See the full article here .


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About the LSC

The LIGO Scientific Collaboration (LSC) is a group of scientists seeking to make the first direct detection of gravitational waves, use them to explore the fundamental physics of gravity, and develop the emerging field of gravitational wave science as a tool of astronomical discovery. The LSC works toward this goal through research on, and development of techniques for, gravitational wave detection; and the development, commissioning and exploitation of gravitational wave detectors.

The LSC carries out the science of the LIGO Observatories, located in Hanford, Washington and Livingston, Louisiana as well as that of the GEO600 detector in Hannover, Germany. Our collaboration is organized around three general areas of research: analysis of LIGO and GEO data searching for gravitational waves from astrophysical sources, detector operations and characterization, and development of future large scale gravitational wave detectors.

Founded in 1997, the LSC is currently made up of more than 1000 scientists from dozens of institutions and 15 countries worldwide. A list of the participating universities.

Caltech/MIT Advanced aLigo Hanford, WA, USA installation
Caltech/MIT Advanced aLigo Hanford, WA, USA installation

Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA
Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

VIRGO Gravitational Wave interferometer, near Pisa, Italy
VIRGO Gravitational Wave interferometer, near Pisa, Italy

Rochester Institute of Technology (RIT) is a private doctoral university within the town of Henrietta in the Rochester, New York metropolitan area.

RIT is composed of nine academic colleges, including National Technical Institute for the Deaf. The Institute is one of only a small number of engineering institutes in the State of New York, including New York Institute of Technology, SUNY Polytechnic Institute, and Rensselaer Polytechnic Institute. It is most widely known for its fine arts, computing, engineering, and imaging science programs; several fine arts programs routinely rank in the national “Top 10” according to US News & World Report.

The Institute as it is known today began as a result of an 1891 merger between Rochester Athenæum, a literary society founded in 1829 by Colonel Nathaniel Rochester and associates, and Mechanics Institute, a Rochester institute of practical technical training for local residents founded in 1885 by a consortium of local businessmen including Captain Henry Lomb, co-founder of Bausch & Lomb. The name of the merged institution at the time was called Rochester Athenæum and Mechanics Institute (RAMI). In 1944, the school changed its name to Rochester Institute of Technology and it became a full-fledged research university.