Illuminating binary star evolution with observed populations and theoretical modeling
| Název práce v češtině: | Důležité fáze vývoje dvojhvězd studované pomocí pozorovaných populací a teoretického modelování |
|---|---|
| Název v anglickém jazyce: | Illuminating binary star evolution with observed populations and theoretical modeling |
| Klíčová slova: | dvojhvězdy|strojové učení|fotometrie|kontaktní dvojhvězdy|černé díry |
| Klíčová slova anglicky: | binary stars|machine learning|photometry|contact binaries|black holes |
| Akademický rok vypsání: | 2020/2021 |
| Typ práce: | disertační práce |
| Jazyk práce: | angličtina |
| Ústav: | Ústav teoretické fyziky (32-UTF) |
| Vedoucí / školitel: | doc. Mgr. Ondřej Pejcha, Ph.D. |
| Řešitel: | skrytý - zadáno a potvrzeno stud. odd. |
| Datum přihlášení: | 16.07.2020 |
| Datum zadání: | 16.07.2020 |
| Datum potvrzení stud. oddělením: | 29.09.2020 |
| Datum a čas obhajoby: | 26.09.2024 13:00 |
| Datum odevzdání elektronické podoby: | 28.08.2024 |
| Datum odevzdání tištěné podoby: | 28.08.2024 |
| Datum proběhlé obhajoby: | 26.09.2024 |
| Oponenti: | Dr. David Jones |
| Dr. Daniel Stevens | |
| Zásady pro vypracování |
| The goal of this thesis is to revisit and significantly improve previous constraints on critical phases of binary star evolution in the light of qualitatively new data that have recently become available or that will become public in the near future.
The immediate goal is to constrain critical mass ratio for Darwin instability and the ensuing common envelope evolution. When two low-mass stars evolve, they expand, get into contact, and start sharing a common envelope. This "dumbbell-like" object is not in thermal equilibrium, oscillates on a timescale of 100 000 years and secularly evolves to a progressively smaller mass ratio of the two stars. When it reaches a critical masses ratio, the binary should undergo tidal Darwin instability, which leads to a rapid merger and an observable brightening. Finding this critical threshold in observational data has been difficult due to limitations of ground-based photometry. With the new and much more precise space-based data (Kepler, Gaia and TESS satellites) and ground-based spectroscopic surveys (APOGEE, Galah, LAMOST), it is time to revisit this problem. Subsequent goals will be decided together with the student and might include topics like constraints on the imprint of Lidov-Kozai cycles on the binary star population, characterization and modeling of hierarchical multiple stellar systems with astrometric, spectroscopic, and photometric data, identification of perturbed stellar merger remnants in survey data, modeling of binary interaction transients (luminous red novae, intermediate luminosity optical transients). These topics might be studied using data modeling, machine learning, stellar evolution calculations, (radiative)hydrodynamics, population synthesis, or few-body dynamics. |
| Seznam odborné literatury |
| Evolutionary Processes in Binary and Multiple Stars, by Peter Eggleton, pp. . ISBN 0521855578. Cambridge, UK: Cambridge University Press, 2006.
Statistics, Data Mining, and Machine Learning in Astronomy, by Z. Ivencić et al. Princeton, NJ: Princeton University Press, 2014 Rucinski, S. M. 2001. The Photometric Amplitude and Mass Ratio Distributions of Contact Binary Stars. The Astronomical Journal 122, 1007. Naoz, S. 2016. The Eccentric Kozai-Lidov Effect and Its Applications. Annual Review of Astronomy and Astrophysics 54, 441. Hwang, H.-C., Zakamska, N. L. 2020. Lifetime of short-period binaries measured from their Galactic kinematics. Monthly Notices of the Royal Astronomical Society 493, 2271. Zinn, J. C., and 12 colleagues 2017. Variable classification in the LSST era: exploring a model for quasi-periodic light curves. Monthly Notices of the Royal Astronomical Society 468, 2189. |
| Předběžná náplň práce v anglickém jazyce |
| With the discovery of gravitational waves from merging compact object binaries and the associated electromagnetic signatures there has been renewed interest in properly understanding and characterizing binary star evolution and especially its violent phases such as common envelope evolution. At the same time, astronomy has witnessed a tremendous growth of available data thanks to dedicated time-domain surveys. The goal of this project is to provide novel constraints on the critical binary star evolutionary phases on the interface of complex data modeling and theoretical inquiry. |