Gravitational waves are
ripples in space and time produced by the bulk acceleration of
matter. They are a prediction of Einstein's
and are very different from gravity waves (i.e., the ripples in water
on the surface of a pond). The existence and detection of
gravitational waves have a long and tumultuous history, even pitting
Albert Einstein against one of the most reputable journals in the
United States. Gravitational waves carry energy and momentum and have
indirectly been detected through the decay in the orbit of the famous
Hulse-Taylor binary pulsar, earning the discoverers Hulse and Taylor a
Nobel Prize in Physics in 1993.
One of the best sources
of gravitational waves is the merger of two black holes, which are
often the most energetic events in the Universe. Nevertheless, the
changes in distance and time a passing gravitational wave induces.
The billion dollar LIGO detectors hope to detect changes in distance
of order one in 1023
. This is comparable to the ratio of
distances a person causes the entire Earth to move when she jumps!
My work has so far has focused on sources of
gravitational waves detectable by LIGO and other ground-based
gravitational wave detectors. I have shown with Bence Kocsis and Avi
Loeb that there is a class of eccentric mergers that occur in the
centers of galaxies. Because they are eccentric these mergers are
distinguishable from nearly all other mergers of black holes in the
universe. We also analyzed the gravitational wave signatures of
eccentric mergers and showed that they are detectable to greater
distances and over longer periods of times than traditional sources.
At Northwestern with Fred Rasio and collaborators, I looked at the
merger of black holes in dense star clusters. Here black holes sink
to the center of the cluster and form tight binaries. We showed when
these binaries merge they are almost always circular and that Advanced
LIGO is likely to detects tens of these events every year. In
addition we looked at how these black holes may occasionally merge to
form ever larger black holes, eventually forming intermediate mass
black holes. We showed that for realistic recoil velocities, these
black holes are more than likely ejected from the cluster before this
My Relevant Papers
STAR CLUSTERS AROUND RECOILED BLACK HOLES IN THE MILKY
WAY HALO : N-BODY SIMULATIONS AND A CANDIDATE SEARCH THROUGH THE SDSS.
R. M. O'Leary and A. Loeb.
MNRAS, 421:2737, April 2012.
GRAVITATIONAL WAVES FROM SCATTERING OF STELLAR-MASS BLACK HOLES IN
R. M. O'Leary, B. Kocsis, and A. Loeb.
MNRAS, 395:2127, June 2009.
STAR CLUSTERS AROUND RECOILED BLACK HOLES IN THE MILKY WAY HALO.
R. M. O'Leary and A. Loeb.
MNRAS, 395:781, May 2009.
DYNAMICAL INTERACTIONS AND THE BLACK-HOLE MERGER RATE OF THE
R. M. O'Leary, R. O'Shaughnessy, and F. A. Rasio.
Phys. Rev. D., 76(6):061504, September 2007.
BINARY MERGERS AND GROWTH OF BLACK HOLES IN DENSE STAR CLUSTERS.
R. M. O'Leary, F. A. Rasio, J. M. Fregeau, N. Ivanova, and
ApJ, 637:937, February 2006.