Analyzing High-Energy Transients: Spectral and Polarization Studies for Gamma-Ray Bursts and Accreting Black Holes- [electronic resource]
Analyzing High-Energy Transients: Spectral and Polarization Studies for Gamma-Ray Bursts and Accreting Black Holes- [electronic resource]
- 자료유형
- 학위논문파일 국외
- 최종처리일시
- 20240214100428
- ISBN
- 9798380381963
- DDC
- 530
- 저자명
- Lazar, Hadar.
- 서명/저자
- Analyzing High-Energy Transients: Spectral and Polarization Studies for Gamma-Ray Bursts and Accreting Black Holes - [electronic resource]
- 발행사항
- [S.l.]: : University of California, Berkeley., 2023
- 발행사항
- Ann Arbor : : ProQuest Dissertations & Theses,, 2023
- 형태사항
- 1 online resource(182 p.)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 85-03, Section: B.
- 주기사항
- Advisor: Tomsick, John;Bale, Stuart.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Berkeley, 2023.
- 사용제한주기
- This item must not be sold to any third party vendors.
- 초록/해제
- 요약High-energy transient events can be used to probe the extreme physics that power them, as well as the properties of matter in violent astrophysical environments such as in the vicinity of compact objects or the birthplaces of black holes. X-ray binary outbursts provide important insights into the physics of accretion and the nature of black holes and neutron stars. Meanwhile, gamma-ray bursts (GRBs) carry signatures of the powerful progenitors that produce them, yet the origins of their prompt emission and their jet structure remain unclear. Spectral and timing analyses have been effective investigative tools for these extreme settings, especially as telescopes advance and models increase in predictive power. Pairing them with linear polarization analyses of high-energy emissions can add even more information about the emission mechanisms and source geometries of accreting black holes and GRBs.The Compton Spectrometer and Imager (COSI) is a soft gamma-ray (0.2−5 MeV) telescope designed to study astrophysical sources including accreting black holes and GRBs. It has significant heritage as a balloon-borne telescope, and was selected as a NASA Small Explorer (SMEX) slated to launch on a satellite in 2027. COSI employs a compact Compton telescope designed to conduct high-resolution spectroscopy, imaging over a wide field-of-view, polarization studies, and effective suppression of background events. Compton telescopes detect multiple interactions from individual incoming photons, allowing for polarization information to be captured through measurements of the distribution of azimuthal angles. While the standard method relies on binning the photons to produce and fit an azimuthal scattering angle distribution, improved polarization sensitivity is obtained by using additional information to more accurately weigh each event's contribution to the likelihood statistics. In this work, we report validations of COSI's capabilities as a polarimeter. Furthermore, we develop tools that enable future spectral and polarimetric analyses of COSI GRB observations.We also present the first observed outburst from the transient X-ray binary source MAXI J0637-430, based on observations from the Nuclear Spectroscopic Telescope Array (NuSTAR) and the Neil Gehrels Swift Observatory X-Ray Telescope (Swift/XRT). We study the source's transition from a soft state dominated by disk-blackbody emission to a hard state dominated by a power-law or thermal Comptonization component, with NuSTAR providing the first coverage of MAXI J0637-430 above 10 keV. These broadband spectra show that a two-component model does not provide an adequate description of the soft state spectrum. As such, we test alternative excess emission models such as blackbody emission from the plunging region, a reflection component with a Comptonization continuum, and a reflection component of a blackbody illuminating the disk. The study demonstrates the importance of broadband spectral analyses of accreting compact objects. We include a discussion on how joint spectral and polarization analyses could be conducted for long-duration transient sources with COSI in the future.
- 일반주제명
- Physics.
- 일반주제명
- Astrophysics.
- 일반주제명
- Aeronomy.
- 키워드
- Gamma-ray bursts
- 키워드
- Spectroscopy
- 기타저자
- University of California, Berkeley Physics
- 기본자료저록
- Dissertations Abstracts International. 85-03B.
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.