Research

   I am a Ph.D. student at the Astronomy department of Cornell University. I work with James Cordes on pulsar searches at various frequencies: I'm currently involved in three search projects.

    1. The PALFA Galactic Plane pulsar survey.

   The PALFA (Pulsar-ALFA) consortium is a group of astronomers from around the world who have pooled efforts and expertise to best utilize the  new ALFA receiver (1.42 GHz) at the Arecibo Observatory. The master goal of the project is to do a "Galactic census" of pulsars, searching the part of the Galactic plane visible from Arecibo over the next few years. Observations started in August 2004 and currently there are several more runs scheduled for the first half of 2005. The survey is expected to find hundreds of new pulsars, based on models of the spatial distribution of ionized gas and neutron stars in the Galaxy.

   The PALFA survey will eventually accumulate a petabyte of raw data which will be archived permanently at Cornell's Theory Center and made publicly available. The new mass storage system and supercomputer are currently configured and tested to be ready for the deluge of data to follow in a few months. 

   PALFA script tools:

• Tablesearch: Browse tables of the PALFA database at Cornell Theory Center.
• Singlesearch: Retrieve PALFA pointing info and NVO images for a selected field of view.
• Batchsearch: Retrieve PALFA pointing info and NVO images for list of fields.
• SNR comparison (blind,precursor): Comparison of blind PALFA redetections of known pulsars with expected SNR values.
• SNR comparison (blind,main): Comparison of blind PALFA redetections of known pulsars with expected SNR values.
• SNR comparison (targeted,Quicklook): Comparison of targeted PALFA redetections of known pulsars with expected SNR values.
• SNR comparison (targeted,Cornell): Comparison of targeted PALFA redetections of known pulsars with expected SNR values.

    Check out the aptly chosen "official" PALFA logo courtesy of Jason Hessels (bearing in mind that pulsars spin around tens to hundreds of times per second). 

   2. High-frequency survey of the Galactic Center.

   In April and May 2004 we made observations of the region around Sgr A* with the Green Bank Telescope at 9 GHz. We are still processing the data from these observing runs, hoping to find pulsars near the Galactic Center. This is a very interesting region, although difficult to survey because the higher density of ionized gas in the inner Galaxy would cause a lot of scattering and dispersion of any pulsar signals coming from there. There are currently no known pulsars within a degree of Sgr A* and only a few within 2 degrees. 

    We used the new SPIGOT backend, which almost made us believe pulsars would start tumbling out (I don't know who the author of this logo is, I admit to nicking it from the Green Bank site). 

   3. Low-frequency drift scan search.

   In collaboration with Paulo Freire from AO we are processing data from a drift scan search at the Arecibo Telescope (327 MHz). The advantage of observing at such a low frequency is that pulsars have higher flux at lower frequencies. The disadvantage is that lower frequencies suffer more dispersion. Drift scan searching is probably the most "low-maintenance" type: park the dome, turn the receiver on, collect data as the sky drifts through the beam. This way we can even scavenge telescope time when tracking temporarily doesn't work (e.g. because of hurricane damage).

   For a non-scientific, off-kilter combination of pulsar and life experience, go here.