Seminar Title |
The Swift GRB redshift distribution: selection effects or luminosity evolution
|
Speaker: |
Prof. David Coward |
Affiliation: |
(University of Western Australia) |
|
|
When: |
Tuesday afternoon, Sept. 10th , 16 : 00 p.m |
Where: |
The 1st Floor, SOFTECH Building (NJU) |
|
|
Welcome to Attend |
|
|
( PMO Academic Committee & Academic Circulating committee) |
|
|
Abstract
We employ realistic constraints on selection effects to model the Gamma-Ray Burst (GRB) redshift distribution using Swift triggered redshift samples acquired from optical afterglows. Models for the Malmquist bias, redshift desert, and the fraction of afterglows missing because of host galaxy dust extinction, are used to show how the “true” GRB redshift distribution is distorted to its presently observed biased distribution. Our analysis, which accounts for the missing fraction of redshifts in the two data subsets, shows that a combination of selection effects (both instrumental and astrophysical) can describe the observed GRB redshift distribution. The observed distribution supports the case for dust extinction as the dominant astrophysical selection effect that shapes the redshift distribution.