Hope College Department of Physics and Engineering
Research Experiences for Undergraduates
Summer 2005
Project Summary


Project Title:

Developing a Luminosity Model for Single-Peak Radio Pulsars

Student Name: Brenna Giacherio
Student's Home Institution: Hope College
Research Advisor: Dr. Peter Gonthier
Source of Support: Research Corporation

Despite the fact that the first pulsar was discovered nearly forty years ago, the mechanism that powers them is still not entirely known. In this project, we are concentrating on pulsars with a single radio peak. By constraining the viewing geometry of each pulsar, we are able to determine the flux at the peak of the emission from which we also obtain the luminosity. We assume that pulsars are standard candles. That is, their luminosity is a function of period and period derivative. The viewing geometry is found using the intensity plot as well as the maximum rate of change of the position angle sweep. In addition, we assume that there are two beams of emission near the polar cap: core and cone. A single peak may be a core, an edge of a cone, or a partial cone. The partial cone merely has a missing second conal peak. Each pulsar is fitted, using our fitting program, as all three possibilities and the parameters are then compared in order to determine the type of emission being seen. The trends we obtain in the data will be incorporated into our simulation code (refer to the work of Sarah Story) for use with GLAST.

We express our gratitude for the generous support of the Michigan Space Grant Consortium, of Research Corporation (CC5813), of the National Science Foundation (REU-0452206 and AST-0307365) and the NASA Astrophysics Theory Program

"The role of core and cone beams in radio pulsar emission", Gonthier, P.L., Story, S.A., Giacherio, B.M., Arevalo, R.A., and Harding, A.K.,American Astronomical Society Meeting 207, January 2005. #183.12

"Developing radio beam geometry and luminosity models of pulsars", Gonthier, P.L., Story, S.A., Giacherio, B.M., Arevalo, R.A., and Harding, A.K. Chinese Journal of Astronomy and Astrophysics, 6, (2006) pp.97-104.