eprintid: 17199
rev_number: 12
eprint_status: archive
userid: 1304
dir: disk0/00/01/71/99
datestamp: 2014-08-04 09:42:06
lastmod: 2014-09-10 11:21:37
status_changed: 2014-08-04 09:42:06
type: doctoralThesis
metadata_visibility: show
creators_name: Hillert, Andreas
title: GRASP - Development of an event reconstruction method using a
Gamma Ray Air Shower Parameterisation and application to 
gamma-ray sources with H.E.S.S.
subjects: ddc-520
subjects: ddc-530
divisions: i-130001
adv_faculty: af-13
abstract: The H.E.S.S. experiment, with its high sensitivity and large field-of-view, is an ideal instrument to survey the Milky Way in VHE gamma-rays. An accurate reconstruction of
the gamma-ray direction as well as a strong reduction of the hadronic background is essential for the analysis of the data. In this work a reconstruction algorithm is developed that applies a fit of pixel amplitudes to an expected image obtained from a Gamma Ray Air Shower Parameterisation (GRASP). This parameterisation was obtained using Monte Carlo air shower simulations by parameterising the angular Cherenkov photon
distribution with suitable analytical functions. Furthermore, it provides new classifying
variables to differentiate gamma-ray induced air showers from hadronic ones. The reconstruction of air shower parameters is achieved by a maximum likelihood fit and improves the angular resolution by 20-30% with respect to traditional image moment analysis methods. In combination with a MVA-based background rejection method using these
new classifying variables the sensitivity can be improved by about 70%. An analysis of the Pulsar Wind Nebula MSH 15-5-2 and investigation of its morphology and spectral
properties show an indication of energy dependent morphology in VHE gamma-rays.
date: 2014
id_scheme: DOI
id_number: 10.11588/heidok.00017199
ppn_swb: 1659172888
own_urn: urn:nbn:de:bsz:16-heidok-171999
date_accepted: 2014-07-24
advisor: HASH(0x55fc36bfe358)
language: eng
bibsort: HILLERTANDGRASPDEVEL2014
full_text_status: public
citation:   Hillert, Andreas  (2014) GRASP - Development of an event reconstruction method using a Gamma Ray Air Shower Parameterisation and application to gamma-ray sources with H.E.S.S.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/17199/1/PhD-Thesis-AndreasHillert-Final.pdf