Material Type  

 학위논문

 

0016932128

Date and Time of Latest Transaction  

20240214100416

ISBN  

9798380382359

DDC  

523

Author  

Beechert, Jacqueline Nicole.

Title/Author  

Understanding Galactic 26Al With the Compton Spectrometer and Imager - [electronic resource]

Publish Info  

[S.l.] : University of California, Berkeley., 2023

Publish Info  

Ann Arbor : ProQuest Dissertations & Theses, 2023

Material Info  

1 online resource(249 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 85-03, Section: B.

General Note  

Advisor: Tomsick, John;Bale, Stuart.

학위논문주기  

Thesis (Ph.D.)--University of California, Berkeley, 2023.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Abstracts/Etc  

요약Aluminum-26 (26Al) is a radioactive isotope produced in massive star processes. High-resolution spectroscopy of its 1.809 MeV gamma-ray (γ-ray) decay signature constrains the dynamics of its emission as it is ejected from its progenitor sites and incorporated into the interstellar medium of the Milky Way Galaxy. Imaging reveals dominant emission in the Inner Galaxy and emission in localized regions of massive star activity. Taken together, spectroscopy and imaging of 26Al shed light on the chemical evolution of the Galaxy over millions of years.The Compton Spectrometer and Imager (COSI) is a compact Compton telescope designed to measure astrophysical γ-rays of energy 0.2-5 MeV. Its high-purity germanium detectors track incident photons as they Compton scatter throughout the detector volume. In 2016, COSI flew on a NASA ultra-long duration balloon for 46 days. This dissertation details the first analysis of 26Al in the flight data and reports a measurement of 3.7σ significance above background and an Inner Galaxy flux of (8.6 ± 2.5) x 10−4 ph cm−2 s−1. All scientific achievements from the flight are predicated on calibrations performed before launch. These calibration procedures were repeated in advance of an intended 2020 balloon flight. Analyzing calibration data validates instrument performance and informs studies of detector effects, including charge sharing and charge trapping, that complicate the measurement process.The next generation of COSI as a NASA Small Explorer satellite is slated for launch in 2027. It is anticipated to strengthen the spectroscopic measurement of 26Al in the balloon flight and yield the most detailed images of 26Al to date. Extensive testing of the imaging algorithm in COSI's new analysis toolkit is presented as a first step towards producing these images. The desired culmination of these efforts is an enhanced understanding of Galactic 26Al by way of thorough calibrations, novel insight into undesirable detector effects, and advanced analyses of high-resolution data from the COSI balloon and satellite instruments.

Subject Added Entry-Topical Term  

Astrophysics.

Subject Added Entry-Topical Term  

Physics.

Subject Added Entry-Topical Term  

Astronomy.

Index Term-Uncontrolled  

Aluminum-26

Index Term-Uncontrolled  

Calibration

Index Term-Uncontrolled  

Compton Spectrometer and Imager

Index Term-Uncontrolled  

Compton telescope

Index Term-Uncontrolled  

Gamma-ray astrophysics

Added Entry-Corporate Name  

University of California, Berkeley Physics

Host Item Entry  

Dissertations Abstracts International. 85-03B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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소장사항  

202402 2024

Control Number  

joongbu:644004