See this page for more discussion.
research projects of possible interest to students in the following sub-fields:
Current projects that I am actively looking for students for:
Section below is dated - will update as and when I can...
I work on or am actively interested in a number of topics in astrophysics:
I am primarily interested in studying the formation, number density and rate of events of a number of different astrophysical sources of gravitational radiation.
There are a lot of potentially interesting student level projects, both 2nd year short projects and thesis projects in this field...
cf. high mass-ratio sources of low frequency gravitational radiation
Cosmic
Genesis Conf. Proc. paper
or the original paper
with Martin Rees
and alternative channels for LIGO sources (cf Sigurdsson and Hernquist,
Nature, 364, 423-425 (1993);
Phinney and Sigurdsson,
Nature, 349, 220-222 (1991))
This work is now done under the auspices of the NSF funded Center for Gravitational Wave Physics
There are a lot of potentially interesting student level projects, both 2nd year short projects and thesis projects in this field...
cf. Planets in Globular Clusters
also 47 Tuc search
and associated modeling
the probable planet in M4 is my personal favourite
Scientific American top science stories of 2003
Discover Magazine top 100 stories of 2003 (we're number 11)
NASA Office of Space Science FY2003 Accoplishments: see "Space Science Summary PDF" at this link
and then there is the whacky bit
Planets in Globular Clusters: a HST project
This work is done under the auspices of NAI through PSARC
Specifically globular clusters for now.
This is an underdeveloped field, lots of interesting modeling
to do and comparisons with observations, both on structure
of clusters, and the stellar populations.
Primary current interest is possible implications of black holes in globular clusters.
see "the Bet"
My current interest is formation and detection scenarios for BH-PSR binaries, scenarios for formation of millisecond pulsars in clusters, and NS binaries as gravitational radiation sources.
black holes in triaxial galaxies; binary black holes; tidal disruption of stars; gas dynamics in realistic galaxy potentials with accreting black holes.
Active galactic nuclei; "feeding the monster" - how the above relates to this.
A possible new direction is advanced techniques for signal extraction and library searches for medium sized gravitational radiation; this is too speculative at the current stage for student involvement, the approach may not work.
More detail and links will be added here over the next
few months, years, Real Soon Now...
Below are some more details, this will be reorganised Real Soon Now...
A project now finished was to use the Hubble Space Telescope to look for planets in the globular cluster 47 Tuc. The project was approved for cycle 8 as GO-8267, PI R. Gilliland at STSCI.
A more succesful project finally found the predicted cluster planet
This is a picture taken by the Hubble Space Telescope of
the young stellar cluster NGC 1818. The cluster is thought
to be about 40 million years old and contains a few tens of
thousands of stars. As part of a large project studying the formation
and evolution of stars in clusters, we (Becky Elson, Gerry Gilmore, Baslio
Santiago (Brazil)
and Sverre Aarseth, Melvyn Davies at the IoA, and myself)
recently discovered a candidate young, luminous white dwarf
in this cluster. If the discovery is confirmed, this will
strongly constrain the critical boundary at which massive
stars detonate as type II supernovae.
See this page for more discussion.
Some of the simulations we do look awful pretty... (more will be added as I get around to doing it).
I work on a number of topics, some of which can easily provide aesthetically pleasing pictures. While not always of profound scientific importance, they can be nice to look at.
One of my current projects is dynamical simulations of elliptical galaxies containing black holes. Here is an animation done by Roeland van der Marel at the Pittsburgh Supercomputer Center using a programme I wrote based on an algorithm deviced by Lars Hernquist and Jerry Ostriker. Some of the details are published in a paper we co-authored.
M32 simulation movie. The original can be found
at this URL.
I've always been interested in pulsars, here
is a very nice plot of pulsar properties, originally due to
Sterl Phinney.
Some of the details of work I have done are discussed in
the TAPIR
graduate recruitment
brochure.
Pulsars are present in binaries, and globular clusters
(here is a very pretty HST picture
of the core of M15, a pulsar rich environment).
Binaries undergo some fascinating chaotic resonant interactions
with single stars and each other in dense stellar environments.
Some of my research has been into the properties of such
resonances - this is a 2D
binary-single resonance, that Aylwyn Scally, a student at the IoA
was working on the summer of 1995.
This was an extension of previous work I did on
binary single resonances.
With David Bacon and Mel Davies I've also
worked on binary-binary resonances.
During such interaction a lot of things may happen. If one of the stars has a planetary companion it may be exchanged as shown here. Or the stars may collide, here is a series of snapshots from a SPH simulation of a 4-way star collision (the point are neutron stars, the other two stars are main sequence stars) from a set of calculations I did with Lars Hernquist back in 1992.
I'm currently working on galactic dynamics and massive black holes, more pictures and comments will be added as I get around to it.
Last updated 09/07
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