E-Dissertationen: Browsing E-Dissertationen by Author "Langer, Norbert"
Now showing items 1-20 of 43
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Binary star population synthesis: Progenitors of gravitational wave driven mergers
Kruckow, Matthias U. (2018-06-13)The vast majority of all massive stars are born in binaries. The binarity of a star may influence its life drastically via a large variety of interactions with its companion star. Several astrophysical events, like the ... -
Comprehensive population synthesis predictions for massive binary stars in the Small Magellanic Cloud
Xu, Xiao-Tian (2024-01-30)The past and ongoing gravitational wave detections have fostered a wide interest in understanding the formation of binary black holes (BBHs). Several formation scenarios have been proposed, including the evolution of ... -
The Dusty, Molecular Envelopes of Red Supergiant Stars: VY Canis Majoris as the Archetypal Example
Verheyen, Lies (2011-11-15)Red supergiant stars are surrounded by dusty envelopes, which harbor a multitude of molecules. Often, they are also known to show maser emission. We collect a sample of 88 red supergiants associated with Galactic open ... -
Envelope inflation in massive stars near the Eddington limit
Sanyal, Debashis (2016-12-21)Massive stars, i.e. those stars with masses more than about 10 times that of the Sun, are important agents for the chemical and dynamical evolution of galaxies. Because of the steep mass-luminosity relation, massive stars ... -
Evolution of carbon-enhanced metal-poor stars originating from mass transfer in stellar binaries
Matrozis, Elvijs (2018-03-26)As the hydrogen and helium created shortly after the Big Bang is gradually processed into heavier elements by successive generations of stars, the overall metal content of the Universe increases. Metal-poor stars which, ... -
The evolution of low-metallicity massive stars
Szécsi, Dorottya (2016-08-11)Massive star evolution taking place in astrophysical environments consisting almost entirely of hydrogen and helium – in other words, low-metallicity environments – is responsible for some of the most intriguing and energetic ... -
The evolution of massive stars in the Small Magellanic Cloud
Schootemeijer, Abel (2019-03-27)Massive stars in the early universe are born with only a small amount of heavy elements (or, 'metals’). These metal-poor massive stars played a crucial role in shaping the galaxies in the early universe. They are also the ... -
Evolution of short-period massive binary stars in the Magellanic Clouds
Sen, Koushik (2022-10-14)Massive stars tend to form in close binaries that will interact during their lifetime. Up to one-third of them are so close that they undergo mass transfer during hydrogen burning and yield most of the observable ... -
The formation mechanisms of classical emission line stars
Hastings, Ben James (2023-10-10)Classical emission line stars are known fast rotators hosting a decretion disc in which emission lines are formed. Since their discovery in 1866, the formation mechanism of this class of stars has proved difficult to ... -
Formation of low-mass helium white dwarfs orbiting binary millisecond pulsars
Istrate, Alina G. (2017-04-25)Millisecond pulsars (MSPs) belong to a class of radio pulsars characterized by high rotational spin rates and low magnetic fields. These neutron stars are believed to be the end-product of binary evolution, in which an old ... -
Gravity Tests with Pulsars Using New-Generation Radio Telescopes
Hu, Huanchen (2023-05-23)Pulsar timing is a powerful tool for studying a wide range of questions in fundamental physics, including the equation of state (EOS) of super-dense matter, tests of general relativity (GR) and alternative theories of ... -
Helium Accreting White Dwarfs as Progenitors of Explosive Stellar Transients
Neunteufel, Patrick (2017-11-27)Accretion induced transients, which are thought to include the important, yet little understood, supernovae (SNe) of the Type Ia, are among the most luminous events observable in the cosmos. However, SNe Ia are only one ... -
High precision timing
Graikou, Eleni (2019-04-30)Pulsars are highly magnetised, fast spinning neutron stars, formed after a supernova explosion. Pulsars have been used to study a wide range of physical and astrophysical phenomena. The majority of science that we can do ... -
The impact of binary interaction on the main-sequence morphology of young star clusters
Wang, Chen (2022-03-04)Star clusters play a vital role in our understanding of stellar physics and evolution, because they are believed to contain stars born at the same time, with the same initial conditions. Therefore, the distribution of the ... -
The impact of tides and mass transfer on the evolution of metal-poor massive binary stars
Marchant Campos, Pablo (2018-05-24)Stars more massive than 10Msun , although few in number compared to objects like our sun, play a very large role in the evolution of the universe. Through strong winds and supernovae they enrich the interstellar medium ... -
Innovative Pulsar Searching Techniques: or Fantastic Pulsars and How to Find Them
Cameron, Andrew David (2018-06-14)Pulsars are rapidly rotating, highly magnetised neutron stars which emit beams of electromagnetic radiation from their magnetic poles, most commonly in the radio spectrum. These massive and extremely compact objects have ... -
Instabilities in the envelope of stars
Grassitelli, Luca (2016-12-22)Stars shine, id est they release energy from their surfaces. This energy is mostly provided by thermonuclear fusion in their cores, and has thus to be transported through the whole star. Especially in the low density outer ... -
Long-term timing of pulsars in globular clusters
Ridolfi, Alessandro (2017-12-20)Pulsars are fast rotating, magnetized neutron stars that result from the supernova explosion of massive stars. Thanks to their coherent radiation, emitted in the form of collimated beams from the two magnetic poles, pulsars ... -
Massive stars on the main sequence
Köhler, Karen (2017-03-10)Massive stars have a strong influence on their environment by chemical enrichment of the surrounding interstellar medium due to strong stellar winds. The influence of mass loss and rotation on the main-sequence evolution ... -
Millisecond pulsars in the era of sensitive telescopes
Gautam, Tasha (2023-01-09)Pulsars are highly magnetised rapidly rotating neutron stars that emit beams of electromagnetic radiation. Millisecond pulsars (MSPs) are a class of recycled pulsars that rotate with exceptionally small spin periods. They ...