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‘Mosh Pits’ in Star Clusters a Likely Source of LIGO’s First Black Holes

Black Hole Encounter

Credit: Aaron Geller/CIERA

In a new study, CIERA astrophysics show their theoretical predictions last year were correct: The historic merger of two massive black holes detected Sept. 14, 2015, could easily have been formed through dynamic interactions in the star-dense core of an old globular cluster.

These binary black holes are born in the chaotic “mosh pit” of a globular cluster, kicked out of the cluster and then eventually merge into one black hole. This theory, known as dynamical formation, is one of two recognized main channels for forming the binary black holes detected by the Advanced LIGO (Laser Interferometer Gravitational-Wave Observatory). Read the full Northwestern News story.

The paper, titled “Dynamical Formation of the GW150914 Binary Black Hole,” was published June 10 by The Astrophysical Journal Letters. It was coauthored by CIERA’s Fred Rasio, Carl Rodriguez, Sourav Chatterjee, and Vicky Kalogera, as well as Carl-Johan Haster of the University of Birmingham.

View the recording of the American Astronomical Society press conference where this discovery was announced. Click on the AAS image in this article (left), or go to the AAS Press Conference Webcast Archive, and click on “Black Holes and Gamma-Ray Bursts” under the AAS 228 San Diego meeting (12-16 June 2016).

View Carl Rodriguez’s TEDx Talk on Binary Black Holes.

June 14, 2016
Daily Mail (U.K.): “Black holes that created gravitational waves formed in a cosmic ‘mosh pit’ of densely-packed stars” by Abigail Beall.

June 15, 2016
New Scientist: “Black hole pairs spat out of mosh pits make gravitational waves” by Jacob Aron.

June 16, 2016
Tech Times: “Gravitational Wave Astronomy – Has LIGO Launched A New Science?” by James Maynard.

June 17, 2016
Physics Today: “LIGO spots a second gravitational wave” by Steven K. Blau.

June 19, 2016
Science News: “More events needed to pin down gravitational waves backstory” by Christopher Crockett.

July 3, 2016
Big Ten Network: “Northwestern reveals undiscovered secrets of the galaxies” by staff writers.