contact info
- Address: NRAO, 520 Edgemont Rd., Charlottesville, VA 22903
- Office: 324 Edgemont
- Phone: 434 244 6838
- Email: pdemores at nrao
research
My main research focus is on observations of radio pulsars, especially the areas of data analysis and instrumentation. High-precision timing of millisecond pulsars gives us a unique "laboratory" for fundamental physics and astrophysics, including tests of general relativity and potential use as a very low frequency (nHz) gravitational wave detector. I am involved in designing and building specialized instrumentation for pulsar observations, with the goal of obtaining the best possible timing precision. I am also exploring new methods for characterizing and compensating for the effect of the interstellar medium (ISM) on the pulsar signals. In addition to improving timing results, this research provides a unique view on the structure of the ionized ISM present in our galaxy.
current projects
- NANOGrav - the North American Nanohertz Observatory for Gravitational Waves. Research collaboration working to detect nHz-frequency gravitational radiation using a pulsar timing array.
- GUPPI - the Green Bank Ultimate Pulsar Processing Instrument. Next-generation FPGA/GPU-based pulsar instrument for the GBT. Records large-bandwidth, high dynamic range, full-Stokes data in filterbank, coherent dedispersion, and baseband modes.
- PSRCHIVE - Data analysis software for pulsar timing, calibration and polarimetry.
- DSPSR - Data analysis software for baseband pulsar data, coherent dedispersion, cyclic spectroscopy, etc.
recent publications
- Limits on the Stochastic Gravitational Wave Background from the North American Nanohertz Observatory for Gravitational Waves, Demorest et al., ApJ submitted (2012). (ADS, arxiv)
- Cyclic Spectral Analysis of Radio Pulsars, Demorest, MNRAS 416, 2821 (2011). (ADS, arxiv)
- A Quantitative Model for Drifting Subpulses in PSR B0809+74, Rosen and Demorest, ApJ 728, 156 (2011). (ADS, arxiv)
- The Massive Pulsar PSR J1614-2230: Linking Quantum Chromodynamics, Gamma-ray Bursts, and Gravitational Wave Astronomy, Ozel et al, ApJ 724, L199 (2010). (ADS, arxiv)
- A two-solar-mass neutron star measured using Shapiro delay, Demorest et al, Nature 467, 1081 (2010). (ADS, arxiv)
presentations
- Tutorial: GPUs in Radio Astronomy from USNC-URSI meeting, Boulder, CO, January 2012.
- Testing Physics with Millisecond Pulsars, given at various colloquia in 2011.
code
- My github account includes all the following packages, and a few assorted other things.
- guppi_daq - the data aquisition code for GUPPI (P. Demorest, S. Ransom)
- Cyclic-Modelling - program for modelling/descattering pulsar cyclic spectra (M. Walker, P. Demorest)
- vdifio - library for parsing VDIF data (A. Deller)