Akshaya Rane

Date of Graduation

2017

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Physics and Astronomy

Committee Chair

Duncan Lorimer

Committee Co-Chair

Kevin Bandura

Committee Member

Paul Cassak

Committee Member

Maura McLaughlin

Committee Member

D J Pisano

Abstract

Fast Radio Bursts (FRBs) are a new class of astrophysical phenomena discovered a decade ago that are characterized by extremely bright millisecond duration radio bursts originating in external galaxies. We have processed archival pulsar survey data obtained with the 64-m Parkes radio telescope in Australia. We used the single-pulse search method to search for pulsars, rotating radio transients (RRATs), and FRBs. RRATs are Galactic pulsars that emit sporadic pulses. We detected 20 known pulsars and one RRAT in this analysis but we did not find any FRBs. We combined this null result with the previous searches carried out with Parkes to constrain an all-sky event rate of FRBs. We used a total of ten surveys and found an event rate of [special characters omitted] events per day per sky above a fluence (observed flux measured in Jansky times the observed width of the pulse in milliseconds) limit of 4.0 Jy ms at the 99% confidence level.;We also carried out a search for host galaxies for RRATs that are at the edge of our Galaxy and therefore present a possibility of being an FRB. We did not find any host galaxy which is within the search beam radius of each of these RRATs. This study suggested that a search for host galaxies should be carried out for future RRAT discoveries for which the dispersion measure (DM) is within the uncertainty of the Galactic free electron density model since these RRATs could be residing in nearby galaxies and could therefore be FRBs.;We also investigated the FRB population by carrying out Monte Carlo simulations of FRBs which have different energy and luminosity distributions. From the maximum likelihood analysis, we found that the known population of FRBs can be best expressed with having Gaussian distributed energy values and has a luminosity distribution that is a power law. The mean energy and luminosity of this distribution were determined to be 4.7 x 1041 ergs and 1.1 x 1045 ergs/s respectively . We concluded that the need to have a power law luminosity distribution implies that FRBs are unlikely to be standard candles. Our main assumption in this analysis was that FRBs are uniformly distributed in the sky (model 1). For the best-fit model, we simulated a distribution that followed star formation history (model 2). We performed Kolmogorov-Smirnov test comparing these two models with each other and with the known sample. From these tests, we conclude that the DM distributions indicate that FRB progenitors do follow the cosmic star formation history. We demonstrate that the two models are distinguishable if the known sample contains at least 100 FRBs.

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