Mass modelling in X-/y-ray astronomy
Mass modelling in X-/y-ray astronomy
The current status of hard X-ray/γ-ray astronomy is briefly reviewed. The next large ESA γ-ray observatory, INTEGRAL, is reviewed both in terms of its instrumentation and its scientific goals. All γ-ray observations are made against a background noise that is large compared with the signal to be measured, which makes understanding of the background crucial. Mass Modelling is currently being developed to enable observatories to better understand their background, improving the quality of data obtained from observations and the sensitivity of the telescope. Much of the current local development of Mass Modelling is driven by the INTEGRAL mission. Mass Modelling within the context of INTEGRAL is reviewed concentrating on The INTEGRAL Mass Model (TIMM).
The background within INTEGRAL is composed of three main components: the prompt cosmic rays, the diffuse γ-ray and the induced radioactivity within the satellite and detectors. To model the third component has required the development of a new code (DECAY). The development and testing of the DECAY code is presented. Testing is carried out using three practical examples: bombardment of a crystal by protons in a high-energy beam; modelling of the background within a low Earth orbit satellite; and, modelling of the background within a high altitude balloon. Having introduced TIMM, and the GGOD software suite used to carry out modelling, the results of recent TIMM simulations are presented and discussed.
The sensitivity of a telescope is a function of its background and its observing time. The IBIS instrument suffers from a large dead time (� 20%). By reducing the dead time, with a minimal increase in the background count rate, the sensitivity of IBIS could be further improved. Two suggested ways for doing this, segmenting (or zoning) the veto and raising the low-energy thresholds of the veto crystals, are investigated using TIMM.
Finally, X-ray observations are presented of the globular cluster 47 Tucanae.
University of Southampton
Ferguson, Colin
b663fd8c-1ff9-4d7d-ac0c-f877a0aa2332
2000
Ferguson, Colin
b663fd8c-1ff9-4d7d-ac0c-f877a0aa2332
Ferguson, Colin
(2000)
Mass modelling in X-/y-ray astronomy.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The current status of hard X-ray/γ-ray astronomy is briefly reviewed. The next large ESA γ-ray observatory, INTEGRAL, is reviewed both in terms of its instrumentation and its scientific goals. All γ-ray observations are made against a background noise that is large compared with the signal to be measured, which makes understanding of the background crucial. Mass Modelling is currently being developed to enable observatories to better understand their background, improving the quality of data obtained from observations and the sensitivity of the telescope. Much of the current local development of Mass Modelling is driven by the INTEGRAL mission. Mass Modelling within the context of INTEGRAL is reviewed concentrating on The INTEGRAL Mass Model (TIMM).
The background within INTEGRAL is composed of three main components: the prompt cosmic rays, the diffuse γ-ray and the induced radioactivity within the satellite and detectors. To model the third component has required the development of a new code (DECAY). The development and testing of the DECAY code is presented. Testing is carried out using three practical examples: bombardment of a crystal by protons in a high-energy beam; modelling of the background within a low Earth orbit satellite; and, modelling of the background within a high altitude balloon. Having introduced TIMM, and the GGOD software suite used to carry out modelling, the results of recent TIMM simulations are presented and discussed.
The sensitivity of a telescope is a function of its background and its observing time. The IBIS instrument suffers from a large dead time (� 20%). By reducing the dead time, with a minimal increase in the background count rate, the sensitivity of IBIS could be further improved. Two suggested ways for doing this, segmenting (or zoning) the veto and raising the low-energy thresholds of the veto crystals, are investigated using TIMM.
Finally, X-ray observations are presented of the globular cluster 47 Tucanae.
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Published date: 2000
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Local EPrints ID: 464247
URI: http://eprints.soton.ac.uk/id/eprint/464247
PURE UUID: cf8ed65b-002e-42b3-8cd6-f7516dcac76f
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Date deposited: 04 Jul 2022 21:44
Last modified: 16 Mar 2024 19:22
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Author:
Colin Ferguson
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