Hope College Department of Physics and Engineering
Research Experiences for Undergraduates
Summer 2006
Project Summary

 

Project Title:

Population Statistics Studies of Millisecond Pulsars in the Galactic Plane

Student Name: Sarah Story
Student's Home Institution: Hope College
Research Advisor: Dr. Peter Gonthier
Source of Support: Michigan Space Grant Consortium, Dean of Natural and Applied Science at Hope College.

Using Monte Carlo techniques, we simulate the birth and evolution of millisecond pulsars. We model the spatial distribution of millisecond pulsars by assuming that they start with a random kick velocity and then evolve through the Galactic potential. We explore both uniform and non- uniform spatial birth distributions within the Galactic plane. After evolution, the radio and gamma-ray fluxes are compared to minimum fluxes for 10 radio surveys and three gamma-ray detectors. An approximation to the birth line dependence on mass accretion rate during spin-up described in Lamb and Yu (2005) has been incorporated into the simulations. We set a random accretion rate between 10-4 and 1 times the Eddington limit, and calculate the birth period, period derivative, and magnetic field based on this accretion rate. Using these new birth characteristics and including several other changes to the program, we obtain good agreement with observed distributions of millisecond pulsars.

*This material is based upon work supported by the National Science Foundation under NSF-REU Grant No. 0452206.

__________________________________________________________________________________________________________________________
Publications and Presentations:

"Population statistics study of radio and γ-ray pulsars from the Galactic disk Neutron Star Populations", Green Bank Observatory, WV (May 21-23, 2007)
"Popluation Synthesis of Radio and Gamma-ray Millisecond Pulsars in the Galactic Disk", First GLAST Symposium, Sanford University (February 5-8, 2007)
"Population statistics of radio and γ-ray pulsars
form the Galactic disk", P.L. Gonthier, S.A. Story, B.D. Clow, and A.K. Harding, 2007, to appear in conference proceedings AIP.
"Popluation Synthesis of Radio and Gamma-ray Millisecond Pulsars from the Galactic Plane", 2007 AAS/AAPT Joint Meeting, American Astronomical Society Meeting 209, #159.07, Bulletin of the American Astronomical Society, Vol. 38, p. 1119.
"Popluation Synthesis of Radio and Gamma-ray Millisecond Pulsars from the Galactic Plane", American Astronomical Society, HEAD meeting #9, #765; Bulletin of the American Astronomical Society, Vol. 38, p.360.
"Population statistics study of radio and gamma-ray millisecond pulsard in the Galactic plane", American Astronomical Society Meeting 207, #183.10; Bulletin of the American Astronomical Society, Vol. 37, p.1469.
"Poplulation synthesis of radio and γ-ray millisecond pulsars form the Galactic disk", S.A. Story, P.L. Gonthier, and A.K.Harding, 2007 ApJ, 671, 713.
"Population synthesis of radio and γ-ray millisecond pulsars form the Galactic disk", S.A. Story, P.L. Gonthier, and A.K. Harding. 2007, The First GLAST Symposium, Sanford, California, February 5-8, 2007, edited by S.Ritz, P. Michelson & C. Meegan, AIP Conference Proceedings, New York, ISBN:978-0-7354-0431-1, 921,226.
"Population statistics of radio and γ-ray pulsars form the Galactic disk", P.L. Gonthier, S.A. Story, B.D. Clow, and A.K. Harding, 2007. The First GLAST Symposium, Sanford, California, February 5-8, 2007, edited by S.Ritz, P. Michelson & C. Meegan, AIP Conference Proceedings, New York, ISBN:978-0-7354-0431-1, 921,431.
"Population statistics study of radio and gamma-ray pulsars in the Galactic plane", P.L. Gonthier, S.A. Story, B.D. Clow and A.K. Harding, 2007, Astrophysics and Space Science, 309, pp. 245-251.

"Population statistics study of radio and gamma-ray pulsars in the Galactic plane", P.L. Gonthier, S.A. Story, B.D. Clow and A.K. Harding, in Proceedings of the Multi-Messenger Approach to High-Energy Gamma-Ray Sources, Barcelona, Spain, July 4-7, 2006, edited by J.M. Pareded, O. Reimer, and D.F. Torres, 2007, Springer, ISBN: 978-1-4020-6117-2, pp. 245-251.