Gamma-Ray Bursts: New Parameters For Measuring Energy Dependent Spectral Lag Times

Author

Phillip Jefferson Durst

Issuing Body

Mississippi State University

Advisor

Lestrade, P. J.

Committee Member

Su, Fu Chun

Committee Member

Winger, Jeff

Date of Degree

12-11-2009

Document Type

Graduate Thesis - Open Access

Major

Computational Engineering (program)

Degree Name

Doctor of Philosophy (Ph.D)

College

James Worth Bagley College of Engineering

Department

Computational Engineering Program

Abstract

A new method for measuring the hardness-intensity correlation (HIC) present in gamma-ray bursts (GRB) is developed. This method is used to measure the HIC for 100 single-peak gamma-ray bursts, 17 with known redshifts. The HIC is thus shown to be a consequence of energy-dependent lag times between hard and soft photons. Parameters derived from time profile fits using a modified double sigmoidal function are used to calculate a new set of lag time parameters for bursts, and these parameters are analyzed statistically to look for correlations with intrinsic GRB properties. This analysis shows that GRB red shift is related to lag times between hard and soft photons and that, to within 65% accuracy, GRB redshift can be predicted by the equation: z = 2.49 - 0.131(dpeak) - 0.473(MADS_dpeak)+ 0.143(decay_lag)

URI

https://hdl.handle.net/11668/17493

Recommended Citation

Durst, Phillip Jefferson, "Gamma-Ray Bursts: New Parameters For Measuring Energy Dependent Spectral Lag Times" (2009). Theses and Dissertations. 2370.
https://scholarsjunction.msstate.edu/td/2370