E-Dissertationen: Suche
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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 ...
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 ...
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 ...
Exploring the environment of high Rotation Measure Active Galactic Nuclei through wide-band radio spectropolarimetry observations
(2016-12-21)
In this Thesis I present an observational study of a sample of radio AGN sources. I study their radio polarization properties in a wide frequency range by observing with the 100-m Effelsberg telescope and the Very Large ...
The Radio Continuum Halos of the Edge-on Galaxies NGC 891 and NGC 4565
(2016-10-13)
The halos of spiral galaxies are complex entities consisting of multiple matter components, generally including neutral and ionized gas phases, cosmic rays (CRs), dust, as well as extraplanar stars. The detection of ...
Some Aspects in Cosmological Perturbation Theory and ƒ (R) Gravity
(2016-09-08)
General Relativity, the currently accepted theory of gravity, has not been thoroughly tested on very large scales. Therefore, alternative or extended models provide a viable alternative to Einstein’s theory. In this thesis ...
Optical Data Analysis and its Application to Cosmology
(2016-03-30)
This work is concerned with different aspects of observational cosmology. It covers a broad range of problems that one needs to deal with in optical astronomy.
Three introduction chapters about cosmology, gravitational ...
Three introduction chapters about cosmology, gravitational ...