520 Edgemont Rd.
Charlottesville, VA USA
Phone / Fax:
434-296-0320 / 0278
Email: sransom at
nrao dot edu
My GPG Key.
I am a staff astronomer at NRAO-Charlottesville
(and a Research Professor in the Astronomy
Dept at UVA) specializing in pulsar
In particular, I search for exotic pulsars (such as binary
and/or millisecond pulsars or MSPs) and then time
them, using their atomic clock-like rotational characteristics to probe
as much basic physics or astrophysics as possible. Recently I've
gotten very interested in the direct detection of gravitational waves
using MSPs. Here in North America that effort is called NANOGrav.
Prior to August 2004, I was a postdoctoral researcher at McGill University in Montreal in Vicky Kaspi's pulsar group.
Before that, I was a graduate student in the Harvard Astronomy Dept.
extremely bored), you can read my thesis here.
PRESTO is the
suite of pulsar search and analysis software (written in C and Python) that I wrote, maintain, and
use. You can get it and some other software on github.
Jim Condon and I are
teaching the UVA
(Astro5340) and our lecture notes are on the
web (Essential Radio Astronomy).
I'm the project scientist for GUPPI,
in the world. The GBT Pulsar Spigot is the pulsar instrument that I used
to be responsible for (may it RIP).
- There is now a tutorial
for PRESTO! Whoa! Go forth and find pulsars...
- The first three
radio-detected but gamma-ray selected Fermi MSPs
are published. We are now up to at least 32 new MSPs!
- Added pySLALIB to github
- Terzan 5 now has 34
is another highly eccentric binary (and was found with coherent GUPPI!).
- New radio MSPs in Fermi unassociated
sources! And lots of em! Here
is a recent short talk on them.
- pySLALIB: Over the past
few days I put together a complete set of python+numpy wrappers (using the fantastic f2py) for the SLALIB
positional astronomy library (developed by P.T. Wallace). The
release includes a complete copy of the Fortran source for SLALIB
itself. Everything is released under the GPL. Hopefully
some of you find it useful.
5 now has 33 pulsars -
although I think this is getting near the limit of what we can do with
the current GBT.
were found by my summer student Ben Sulman
using very deep stack
searches of all our data. We have timing
solutions for 31
of the pulsars, including (we think), Ter5Q,
0.72) binary MSP. Here
is a neat plot that shows an I-band NTT image (from S. Ortolani), with
VLA L-band contours (from Fruchter and Goss 2000), and the 31
timing-based pulsar positions.
- We finally convinced ourselves that the Backer-beater was real
and so we published a paper
(also available here).
and our press
release from the recent AAS meeting as well. Just how fast is
716 Hz? That is what
the pulsar would sound like if we amplified its signal from the GBT by
about 5000 times!
- Recent work on the 7 new M28
pulsars has shows us that M28C
is highly eccentric (e = 0.84) and very interesting...
2005: Two more MSPs (Z
5 now has 31 pulsars, and we have timing
solutions for 28
- One of them, Ter5ad,
appears to (finally) be a "Backer-beating" 1.39ms pulsar! We're
still trying to rule out that it isn't a harmonic of a 2.78ms, pulsar,
- Another one, Ter5ae, is a new
"Black-Widow" type pulsar in a compact binary that my summer student
Mike McCarty found using an automated version of Adam Chandler's
"Dynamic Power Spectrum" technique.
- The GBT has found at least
new globular cluster
pulsars since it has been in operation! Most of these have
been with the fantastic SPIGOT+S-band receiver system.
2005: We've used the GBT to find 21
pulsars in globular cluster Terzan
Here is the abstract
text of the Science paper.
Aug 2004: Moved to
Charlottesville from Montreal.
Last Modified 19 Dec 2012