Semester

Fall

Date of Graduation

2011

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Physics and Astronomy

Committee Chair

Duncan Lorimer.

Abstract

Pulsars are interesting astronomical objects in their own right but, they are also great instruments to use for physics. Their clock-like periodicity allows them to be used to study the interstellar medium, detect gravitational waves, and study binary evolution. In this work we take a look at a general view of the pulsar population through searching for new pulsars, measuring the properties of pulsars through a technique called pulsar timing, and modeling of the pulsar population using Bayesian techniques.;We took advantage of the immobilization of the Robert C. Byrd Green Bank Telescope during the track refurbishing in 2007 to search the sky for radio pulsars at a frequency of 350 MHz. This survey has excellent sensitivity off the Galactic plane but suffers from scattering and dispersion measure smearing in the Galactic plane. So far in this survey we have found 27 new pulsars including six millisecond pulsars of which some are interesting sources that have been studied across the electro-magnetic spectrum.;Rotating radio transients have emission that is periodic but is not always apparent using Fourier domain techniques. These sources may represent a new part of the neutron stars spectrum but present difficulties in studying them. Here we discuss some properties of five rotating radio transients and offer some comments on how they relate to normal radio pulsars.;Globular clusters host a large number of millisecond pulsars. This is expected due to the stellar evolution of the globular cluster. They have a few pulsars much younger than the globular cluster itself. We examined this population of younger pulsars, putting constraints on the possible total population, and examined the globular clusters for evidence of how they could be formed without massive progenitors that are needed for core collapse supernovae. The most likely scenario is accretion induced collapse of a O-Ne-Mg white dwarf.

Download

Share

COinS