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Simulating Bursty and Continuous Reionization Using GPU Computing- [electronic resource]
![Simulating Bursty and Continuous Reionization Using GPU Computing - [electronic resource]](/Users/Baul/Images/book.png)
Simulating Bursty and Continuous Reionization Using GPU Computing- [electronic resource]
상세정보
- 자료유형
- 학위논문파일 국외
- 최종처리일시
- 20240214101553
- ISBN
- 9798380582032
- DDC
- 520
- 서명/저자
- Simulating Bursty and Continuous Reionization Using GPU Computing - [electronic resource]
- 발행사항
- [S.l.]: : University of Maryland, College Park., 2023
- 발행사항
- Ann Arbor : : ProQuest Dissertations & Theses,, 2023
- 형태사항
- 1 online resource(180 p.)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 85-04, Section: B.
- 주기사항
- Advisor: Ricotti, Massimo.
- 학위논문주기
- Thesis (Ph.D.)--University of Maryland, College Park, 2023.
- 사용제한주기
- This item must not be sold to any third party vendors.
- 초록/해제
- 요약Reionization is the process by which the neutral intergallactic medium of the early universe was ionized by the first galaxies, and took place somewhere between roughly redshift 30 and redshift 6, or from 100 Myr into the universe to 1 Gyr. The details of this transition are still not well understood, but observational constraints suggest that reionization happened faster than naive estimates would suggest. In this thesis, we investigate the theory that galaxies which form their stars in short bursts could complete reionization faster than galaxies which emit their photons continuously over their lifespans.We began investigating this theory with a semi-analytic model of the early universe. We used analytic methods to model the expansion of H II (ionized hydrogen) regions around isolated galaxies, as well as the behavior of the remnant H II regions after star formation ceases. We then compiled assortments of galaxies matching dark matter simulation profiles and associated each with an H II region that could either grow continuously or grow quickly before entering a dormant period of recombination. These tests indicated that the remnants of bursty star formation had lower overall recombination rates than those of continuously expanding H II regions, and that these remnants could allow for ionizing radiation from more distant sources to influence ionization earlier.We decided that the next step towards demonstrating the differences between continuous and bursty star formation would require the use of a more accurate model of the early universe. We chose a photon conserving ray tracing algorithm which follows the path of millions of rays from each galaxy and calculates the ionization rate at every point in a uniform 3D grid. The massive amount of computation required for such an algorithm led us to choose MPI as the framework for building our simulation. MPI allowed us to break the grid into 8 sub-volumes, each of which could be assigned to a node on a supercomputer. We then used CUDA to track the millions of rays, with each of the thousands of CUDA cores handling a single ray. Creating my own simulation library would afford us complete control over the distribution and time dependence of ionizing radiation emission, which is critical to isolating the effect of bursty star formation on reionization.Once we had completed, we conducted a suite of simulations across a selection of model parameters using this library. Every set of model parameters we selected corresponds to two models, one continuous and one bursty. This selection allowed us to isolate the effect of bursty star formation on the results of the simulations. We found that the effects we hoped to see were present in our simulations, and obtained simple estimates of the size of these effects.
- 일반주제명
- Astronomy.
- 일반주제명
- Astrophysics.
- 일반주제명
- Physics.
- 키워드
- Cosmology
- 키워드
- Reionization
- 키워드
- Ionized hydrogen
- 기타저자
- University of Maryland, College Park Astronomy
- 기본자료저록
- Dissertations Abstracts International. 85-04B.
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520240214101553
■006m o d
■007cr#unu||||||||
■020 ▼a9798380582032
■035 ▼a(MiAaPQ)AAI30574659
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a520
■1001 ▼aHartley, Blake Teixeira.
■24510▼aSimulating Bursty and Continuous Reionization Using GPU Computing▼h[electronic resource]
■260 ▼a[S.l.]:▼bUniversity of Maryland, College Park. ▼c2023
■260 1▼aAnn Arbor :▼bProQuest Dissertations & Theses, ▼c2023
■300 ▼a1 online resource(180 p.)
■500 ▼aSource: Dissertations Abstracts International, Volume: 85-04, Section: B.
■500 ▼aAdvisor: Ricotti, Massimo.
■5021 ▼aThesis (Ph.D.)--University of Maryland, College Park, 2023.
■506 ▼aThis item must not be sold to any third party vendors.
■520 ▼aReionization is the process by which the neutral intergallactic medium of the early universe was ionized by the first galaxies, and took place somewhere between roughly redshift 30 and redshift 6, or from 100 Myr into the universe to 1 Gyr. The details of this transition are still not well understood, but observational constraints suggest that reionization happened faster than naive estimates would suggest. In this thesis, we investigate the theory that galaxies which form their stars in short bursts could complete reionization faster than galaxies which emit their photons continuously over their lifespans.We began investigating this theory with a semi-analytic model of the early universe. We used analytic methods to model the expansion of H II (ionized hydrogen) regions around isolated galaxies, as well as the behavior of the remnant H II regions after star formation ceases. We then compiled assortments of galaxies matching dark matter simulation profiles and associated each with an H II region that could either grow continuously or grow quickly before entering a dormant period of recombination. These tests indicated that the remnants of bursty star formation had lower overall recombination rates than those of continuously expanding H II regions, and that these remnants could allow for ionizing radiation from more distant sources to influence ionization earlier.We decided that the next step towards demonstrating the differences between continuous and bursty star formation would require the use of a more accurate model of the early universe. We chose a photon conserving ray tracing algorithm which follows the path of millions of rays from each galaxy and calculates the ionization rate at every point in a uniform 3D grid. The massive amount of computation required for such an algorithm led us to choose MPI as the framework for building our simulation. MPI allowed us to break the grid into 8 sub-volumes, each of which could be assigned to a node on a supercomputer. We then used CUDA to track the millions of rays, with each of the thousands of CUDA cores handling a single ray. Creating my own simulation library would afford us complete control over the distribution and time dependence of ionizing radiation emission, which is critical to isolating the effect of bursty star formation on reionization.Once we had completed, we conducted a suite of simulations across a selection of model parameters using this library. Every set of model parameters we selected corresponds to two models, one continuous and one bursty. This selection allowed us to isolate the effect of bursty star formation on the results of the simulations. We found that the effects we hoped to see were present in our simulations, and obtained simple estimates of the size of these effects.
■590 ▼aSchool code: 0117.
■650 4▼aAstronomy.
■650 4▼aAstrophysics.
■650 4▼aPhysics.
■653 ▼aCosmology
■653 ▼aGraphics Processing Unit
■653 ▼aHigh Performance Computing
■653 ▼aReionization
■653 ▼aIonized hydrogen
■690 ▼a0606
■690 ▼a0596
■690 ▼a0605
■71020▼aUniversity of Maryland, College Park▼bAstronomy.
■7730 ▼tDissertations Abstracts International▼g85-04B.
■773 ▼tDissertation Abstract International
■790 ▼a0117
■791 ▼aPh.D.
■792 ▼a2023
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T16934305▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
■980 ▼a202402▼f2024
