E-Dissertationen: Suche
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The Physical Properties of Intermediate-Velocity Gas at High Galactic Latitudes
(2016-07-26)
The accretion of matter onto galactic disks, the formation of molecular clouds, and the formation of stars are of major importance for the evolution of galaxies over cosmic times. During their lifetimes, high-mass stars ...
Physical processes behind the periodic radio and gamma-ray emission from the X-ray binary LS I +61°303
(2016-07-21)
X-ray binaries are binary stars composed of a normal star and a compact object which, via Roche-lobe overflow or wind accretion, accretes matter from the companion. X-ray emission from these objects can be either thermal ...
The evolution of low-metallicity massive stars
(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 ...
Studying galaxy clusters through X-rays and the Sunyaev-Zel’dovich effect: simulations, detection and characterisation
(2016-07-26)
Clusters of galaxies are the largest gravitationally-bound objects in the Universe. Thereby clusters are ideal tracers of cosmic expansion and structure formation that allow tight constraints on the average cosmic density ...
Studying large-scale structures and polarization of the Northern sky facilitating single-station data of the Low Frequency Array (LOFAR)
(2016-07-21)
All-sky surveys help to gather a deep knowledge about the nature of large-scale structures in the Universe, the Milky Way and extragalactic galaxies. In the context of that, observations in the radio domain are important, ...
Kinematics study of M81 and M82 Galaxies
(2016-12-21)
The measurement of proper motion combined with the radial velocities, is an important tool for our understanding of the dynamics and evolution of galaxies in a group environment. One of the nearest group is the M$,$81 group ...
Probing Gravity with High-Precision Pulsar Timing
(2016-12-22)
Pulsars are highly magnetised neutron stars which spin tremendously fast, at periods that are as low as a few milliseconds. Chapter 1 gives an overview of their basic observational properties and applications. Pulsars are ...
Instabilities in the envelope of stars
(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 ...
Envelope inflation in massive stars near the Eddington limit
(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 ...
Pulsar Discoveries and their Exploitation
(2016-12-22)
Pulsars are the rapidly-rotating, highly-magnetized, neutron star remnants of the supernova explosions of massive stars. Pulsars have been used in a wide variety of studies of astronomy and physics. Of the >2500 pulsars ...