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Scientists detect first-of-its-kind ‘intermediate-mass‘ black hole

Numerical simulation of two black holes that inspiral and merge, emitting gravitational waves. Credit: N. Fischer, H. Pfeiffer, A. Buonanno, and the SXS Collaboration

A quick ‘bang’ signals the most massive gravitational-wave source yet

An international research collaboration including Northwestern University astronomers has witnessed the birth of an “intermediate-mass” black hole. This is the first conclusive discovery of an intermediate-mass black hole, an object which has long eluded astronomers. The cosmic event, its energy detected on Earth in the form of gravitational waves, is the most massive black hole merger yet observed in gravitational waves.

Two black holes likely collided and merged to create a more massive black hole with a final mass 142 times that of the sun, or 142 solar masses. This final black hole is the first to be found in an intermediate-mass range that lies between stellar-mass and supermassive black holes.

Another first is that the heavier of the two merging black holes, at 85 solar masses, is the first black hole so far detected within what is known as the “pair-instability mass gap.”

Researchers detected the gravitational-wave signal on May 21, 2019, with the National Science Foundation’s LIGO (Laser Interferometry Gravitational-wave Observatory (LIGO), a pair of identical, 4-kilometer-long interferometers in the United States, and Virgo, a 3-kilometer-long detector in Italy. The signal was dubbed GW190521.

Continue to the full Northwestern News story by Megan Fellman.

Professor Vicky Kalogera, principal investigator of Northwestern’s LIGO Scientific Collaboration group

Christopher Berry

Christopher Berry, CIERA Board of Visitors Research Professor, LIGO Scientific Collaboration Editorial Board reviewer for the discovery paper

Chase Kimball, LIGO Scientific Collaboration member and Northwestern astronomy Ph.D. student, contributed to the analysis of the astrophysical origins of GW190521 in the implications paper

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