4 research outputs found
Intermediate and extreme mass-ratio inspirals — astrophysics, science applications and detection using LISA
Black hole binaries with extreme (gtrsim104:1) or intermediate (~102–104:1) mass ratios are among the most interesting gravitational wave sources that are expected to be detected by the proposed laser interferometer space antenna (LISA). These sources have the potential to tell us much about astrophysics, but are also of unique importance for testing aspects of the general theory of relativity in the strong field regime. Here we discuss these sources from the perspectives of astrophysics, data analysis and applications to testing general relativity, providing both a description of the current state of knowledge and an outline of some of the outstanding questions that still need to be addressed. This review grew out of discussions at a workshop in September 2006 hosted by the Albert Einstein Institute in Golm, Germany
Gravitational Dynamics of Large Stellar Systems
Internal dynamical evolution can drive stellar systems into states of high
central density. For many star clusters and galactic nuclei, the time scale on
which this occurs is significantly less than the age of the universe. As a
result, such systems are expected to be sites of frequent interactions among
stars, binary systems, and stellar remnants, making them efficient factories
for the production of compact binaries, intermediate-mass black holes, and
other interesting and eminently observable astrophysical exotica. We describe
some elements of the competition among stellar dynamics, stellar evolution, and
other mechanisms to control the dynamics of stellar systems, and discuss
briefly the techniques by which these systems are modeled and studied.
Particular emphasis is placed on pathways leading to massive black holes in
present-day globular clusters and other potentially detectable sources of
gravitational radiation.Comment: 21 pages, invited talk presented at the 18th International Conference
on General Relativity and Gravitation (GRG18), Sydney, July 2007. To appear
in Classical and Quantum Gravit
Intermediate and extreme mass-ratio inspirals—astrophysics, science applications and detection using LISA
Relativistic Binaries in Globular Clusters
Galactic globular clusters are old, dense star systems typically containing
10\super{4}--10\super{7} stars. As an old population of stars, globular
clusters contain many collapsed and degenerate objects. As a dense population
of stars, globular clusters are the scene of many interesting close dynamical
interactions between stars. These dynamical interactions can alter the
evolution of individual stars and can produce tight binary systems containing
one or two compact objects. In this review, we discuss theoretical models of
globular cluster evolution and binary evolution, techniques for simulating this
evolution that leads to relativistic binaries, and current and possible future
observational evidence for this population. Our discussion of globular cluster
evolution will focus on the processes that boost the production of hard binary
systems and the subsequent interaction of these binaries that can alter the
properties of both bodies and can lead to exotic objects. Direct {\it N}-body
integrations and Fokker--Planck simulations of the evolution of globular
clusters that incorporate tidal interactions and lead to predictions of
relativistic binary populations are also discussed. We discuss the current
observational evidence for cataclysmic variables, millisecond pulsars, and
low-mass X-ray binaries as well as possible future detection of relativistic
binaries with gravitational radiation.Comment: 88 pages, 13 figures. Submitted update of Living Reviews articl