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The Swinburne pulsar group is interested in developing new technologies that
enable the discovery, timing and exploration of the radio Universe on the smallest
timescales. Together with our colleagues at Caltech, Berkeley and the Australia
Telescope we have developed several generations of instrumentation for precision
pulsar timing that involve custom FPGA boards and large supercomputing clusters.
Our software instruments are used in many institutes around the world for pulsar
and VLBI work.
The software behind all of our hardware is made freely available to the academic
community.
Our group has held the record for the most precise precision timing since
2001, which have enabled tests of general relativity and the best limits
on the cosmological background of gravitational waves.
We have conducted large-scale surveys of intermediate
latitudes for millisecond pulsars, which have discovered many interesting objects,
including PSR J1909-3744, a millisecond pulsar with a very small duty cycle
which delivered the most accurate millisecond pulsar mass.
We are currently developing two exciting new instruments:
APSR is a 1 GHz baseband recorder with a 20-server supercomputing cluster capable of a wide variety
of applications including precision timing, pulsar searching and polarimetry. It uses
the ATNF's DFB3 for the sampling and packetisation of the data.
BPSR is a 13 beam digital filterbank capable of delivering 1024 channels of 8-bit
data for use with the Parkes multibeam receiver. It uses Xilinx chips and was
developed by Werthimer's group at Berkeley. Our software (PSRDADA) captures data from
this board and searches for pulsed emission in real time, and produces 2bit
total intensity data for subsequent pulsar, RRAT and giant burst surveys.
Our software correlator (DiFX) is used to process VLBI data.
At present we are engaged in three major projects:
The Parkes High Time Resolution Universe all-sky surveys are an effort to map the entire
sky at sub-millisecond timescales in the search for pulsars and extragalactic
radio bursts.
The Parkes pulsar timing array is an effort to search for the cosmological
gravitational wave background and uses our instruments to minimise systematic
errors.
The GMRT software backend project is an effort to search for pulsars
and extragalactic bursts at the Giant Metre Wave Telescope and perform
coherent dedispersion of radio pulses.
The Swinburne Pulsar Group is part of the Centre for Astrophysics and
Supercomputing, hosted by the
Faculty of ICT at the
Swinburne University of Technology in Melbourne, Australia.
Research Our group is involved in a number of research
projects and collaborations. Heading our efforts are the Intermediate
and High Latitude Pulsar Surveys, and the High-Precision Timing of
Southern Millisecond Pulsars. We are also actively involved in
studies of interstellar scintillation, single-pulse polarimetry, as
well as the development and design of baseband recording systems and
a baseband software correlator.
We have developed the world's largest bandwidth
coherent dedispersion system at the Parkes radio telescope that
uses sampler boards developed at Caltech and a 60-processor
supercomputer to study pulsars at sub-microsecond time resolution.
This is enabling us to search for the sub-millisecond pulsars
and gravitational waves caused by supermassive coalescing black hole
binaries.
Software We have developed a number of Open Source software
projects that support pulsar research. These are available on
SourceForge under the
Academic Free License.
A development library and set of applications for use in the archival
and analysis of folded pulse profiles.
Digital signal processing for radio pulsar time series analysis.
A modular DSP library is utilized by a multi-threaded data
reduction application capable of 2-bit digitization corrections,
phase-coherent dispersion removal, synthetic filterbank creation,
polarimetric detection, and pulse folding, including single-pulse
and multiple-pulsar (e.g. globular cluster) folding.
Tools for distributed acquisition and data analysis systems development.
This software has evolved through the implementation of three real-time
baseband recording and processing instruments: CPSR2, PuMa-II, and APSR.
Modular clients that read or write to a flexible, multi-stream
ring-buffer are used to manage data flow from acquisition hardware
to analysis software on a workstation cluster. The monitor and
control interface is viewed via web browser, and data can be
sent to remote computing facilities via
gridbus.
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