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The evolution of globular star clusters tells the history of the formation of galaxies, how stellar streams might have formed and how the future of the Universe might look like. Although the general theoretical background of the evolution is well understood, it is difficult to conduct accurate and realistic computer simulations of objects containing thousands of interacting bodies. This project in
What effect does a collision between two clusters have on their dissolving time? In order to answer this question, a new type of N-body simulation using a double integration of a cluster was built. Instead of introducing a perturbation representing the gravitational force of the Milky Way into a local simulation of the cluster, the cluster orbit was integrated in the potential of the Milky Way,
Context. The planet-metallicity correlation for gaseous giants is widely accepted through spectroscopic studies. However, whether a similar correlation exists for terrestrial planets is a debated subject. High-precision spectroscopic abundance analysis on Sun-like stars suggested that the Sun is depleted in refractory elements with respect to its solar twins without exoplanets, likely due to the f
The motivation for the project is to investigate what happens if I add a second Earth in the Solar System and project it forward in time. I add an Earth mass planet (called Earth two) in the same orbit as the Earth on the other side of the Sun (i.e. six months ahead of the original Earth). I then investigate how the perturbation of the second Earth effects the Solar System in the short and the lon
To understand the evolution of our galaxy, the chemical abundance patterns and trends within the stars of the different regions are explored. The process of synthesizing these elements reveals key details about the way the stars and, therefore, the galaxy formed. This project focused on the element potassium, K, and specifically its absorption line 7699 Å. The local thermodynamic equilibrium (LTE)
A transit is a phenomenon where a planet passes between its host star and an observer blocking out part of the light from the star. This decrease can be measured and used to gain information about the planet. The Kepler and TESS telescopes are examples of space telescopes using the transit method to detect exoplanets. For systems with more than one planet around the same star variations between th
The interstellar medium of both local and distant disc galaxies is observed to be supersonically turbulent and the turbulent motion of the gas is thought to be important for galaxy formation and evolution, particularly as a key ingredient for star formation. Consequently, this generates a striking relation between the star formation rate (SFR) and gas velocity dispersion ($\sigma_{\rm g}$; a measu
We probe the implications of 5 different previously developed models of the evolution of the Milky Way’s radial metallicity gradient for radial migration of stars observed today between 5kpc < R < 12kpc. Our sample contains 7167 giant stars, with metallicities and radial velocities obtained from APOGEE DR14, full 5-parameter kinematic information from Gaia DR2, and ages derived in Martig et al. 20
A star forms with a surrounding protoplanetary disk after the collapse of a molecular cloud core. Subsequently, over a period of several Myr this protoplanetary disk of dust and gas is accreted onto the host star. We model the formation and evolution of such a protoplanetary disk using a one-dimensional numerical model. We find that disks form on a time scale of less than 1 Myr and that the size a
Interactions play a crucial role in determining how galaxies evolve in terms of their morphologies and star formation histories, since the majority of the known galaxies in the nearby Universe are found to exist in groups. Compact groups of galaxies are of particular interest as they contain a small number of galaxies in dense configurations and host repeated interactions between them, enabling us
Planetary embryos grow by the accretion of solid dust-material, ranging from cm- to m-sized pebbles up to km-sized planetesimals. However, the underlying size-distribution of the accreted material is poorly understood. When the pebbles and planetesimals encounter a protoplanet, they are subjected to the gaseous environment of the protoplanetary envelope. Because of the drag-force from the gas, the
Planets that orbit their host star closely experience tidal forces due to the strength of gravity not being uniform all over the planet. This leads to effects such as tidal spin synchronization, tidal eccentricity damping and tidal semi-major axis damping. This project aims to study how the time scales for these phenomena are affected by the planetary parameters such as mass, radius and the tidal
One of the biggest mysteries astronomers wish to unveil is the formation and evolution of galaxies. Properties of our own galaxy, the Milky Way, can provide great insight into these. The star formation rate (SFR) and whether it varies with distance from the galactic centre (GC), is one of these properties. Studies indicate that the SFR is higher in the bulge region than in the local thick disk of
The role of massive stars (those with masses greater than eight solar masses) in the chemical enrichment of galaxies and renewed star formation forms an important field of fundamental research in modern astrophysics. The complex nature of massive star evolution produces formidable challenges in furthering our understanding of the processes driving massive star evolution. Our ever-changing picture
In a phase of instability during the dynamical evolution of some multiple exoplanetary systems, exchange of angular momentum and/or energy through gravitational interactions between planets will lead to alterations of their orbital properties. In some cases, planetary orbits end up crossing, which leads to close encounters between two planets. In turn, they undergo a planet--planet scattering even
Double neutron star binaries (DNSBs) in the mHz gravitational wave (GW) regime are an important group of objects which the GW detector LISA will be able to observe. The detection and parametrization of these objects will help develop our current understanding of neutron star formation and evolution. In this thesis, we synthesize a group of DNSBs using data from Church et al. (2011) and normalize t
Stellar streams around the Milky Way (MW) have been observed by wide sky surveys, and studied to understand the mass distribution of the MW. This is because streams are formed by a disruption of a globular cluster or a dwarf galaxy under the influence of the gravitational field of the MW. Moreover, the streams can provide an understanding of dark matter because they orbit in the far outer region o
Binary planetesimals in the Kuiper belt can experience close encounters with other bodies. These encounters can disturb the orbital dynamics of the binary in several ways. Energy can be added to the system by the impactor body and lead to the disruption of the binary. Less energetic encounters can alter the orbital elements of the mutual orbit of the binary. The impactor could swap with one of the
The Laser Interferometer Space Antenna (LISA) is a space borne gravitational wave detec- tor set to launch in 2034, with the objective of detecting and studying the Gravitational Waves (GWs) of our universe. So far, ground-based detectors such as the Laser Interferometer Gravitational-Wave Observatory (LIGO) have been successful in detecting GWs, but the limitations of ground based detectors is wh
