Hope College Physics Department
Research Experiences for Undergraduates
Summer 2008
Project Summary


Project Title: Role of Magnetic Field Decay in Pulsar Population Simulations
Student Name: Melanie Stam
Student's Home Institution: Georgia Tech
Research Advisor: Dr. Peter Gonthier
Source of Support: This material is based upon work supported by the National Science Foundation under NSF-REU Grant No. PHY-0452206, NSF-RUI Grant No. AST-0307365, Michigan Space Grant Consortium, and the National Aeronautics and Space Administration Astrophysics Theory Program.

Recent work by Faucher-Giguére & Kaspi (2006) on pulsar population simulations argues that short timescale (2.5-5Myr) decay of a neutron star’s magnetic field is unnecessary to reproduce observed distributions. They remove the need for field decay by incorporating radio luminosity proportional to the spin-down energy and a period-dependent beaming function (estimating the fraction of pulsars that are beamed towards us). We have modified our code to include their beaming fraction, luminosity and birth distributions. A population of pulsars is evolved from their birth location to the present time, given radio characteristics and filtered through the Parkes Multibeam and Swinburne radio surveys. Given these assumptions, our study does not satisfactorily reproduce the “upside-down pear shape” visible in the period/period derivative chart of detected pulsars. Adding a more realistic description of spin down to our model (Gonthier et al. 2007) that incorporates realistic beam geometry may mimic the effect of (and thus eliminate the need for) field decay.