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The purpose of Galactic archaeology is determining the history of the Milky Way (MW) Galaxy. To do this one uses observational data from stellar populations in terms of properties such as kinematics, chemistry, ages, and evolution. In this context a population means stars with similar characteristics and the most notable population is “the Solar Neighbourhood” (SN). Stars orbit with a ‘guiding rad

I investigate to what extent spiral arms might affect axisymmetric Galactic models. As we need fully dynamical and high resolution Galactic evolutionary models to probe the structure of the dark matter halo, it is important that we use accurate mass models describing the MW structure. Before reaching to that level of effort, a great deal can be learned from fitting mass and kinematic models to dat

The rate of migration and accretion onto protoplanets is greatly influenced by the structure of the surrounding protoplanetary disc. This structure changes with time as the disc evolves on a million year timescale, implying that the process of planet formation might look very different depending on when it was initiated. Further on, the evolution of the disc structure is affected on smaller timesc

Star clusters can harbour many exotic objects, including black holes (BHs), X-ray binaries and blue straggler stars. In dense stellar environments like globular clusters (GCs), two-body relaxation drives their dynamical evolution, where gravitational interactions between stars strive to equalize their kinetic energy in the cluster. Theoretical studies have indicated that some of these clusters can

Purpose: even in the era of exponential increase in the amount of stellar data gathered, binaries are still often overlooked in observational data due to the special handling they require. The goal of this work is to develop a method capable of automatically and efficiently identifying and extract double-lined spectroscopic binaries (SB2) from a spectroscopic survey, while being scalable and techn

Purpose: In order to study the Galactic Chemical Evolution, elemental abundances are needed. The purpose of this work is to investigate the chemical evolution of the Milky Way by determining several elemental abundances of giants in the local disk. Large surveys are up and coming, and several surveys are already working, and with these, the aim is high quality abundance measurements of several ele

In the thriving field of exoplanet research new discoveries are made all the time, and while most of the observed systems can be explained with classical planet formation models - some are much harder to explain. When stars form they are often surrounded by the remaining material of the nebulae they formed from. Some of this remaining material forms into a protoplanetary disk around the protostars

In this report we present the testing and development made using the Lund Observatory Vacuum Echelle Spectrograph (LOVES) during the last few years. Hardware development includes an assembly from base components due to relocation and necessary calibrations of the optics. Software devel- opment includes the making of a basic image processing pipeline for the instrument. The testing of LOVES wavelen

The current Lambda Cold Dark Matter cosmology predicts galaxy growth by hierarchical merging, leading to galaxy substructure like tidal streams and dark matter subhalos devoid of stars. The goal of this thesis is to investigate whether tidal stream-subhalo interactions can leave observable gaps in the streams, and at which rate this might happen in a galaxy like the Milky Way. The stream-subhalo i

Over the past two decades many discoveries of exoplanets have been made, which have drawn much attention to extrasolar planetary systems. In this work we study the composition of these systems and search for analogues of the Solar System. We considered the planets in the database at exoplanet.eu. The search of solar-like systems required these planets to be classified. The classification was perf

A major avenue in the study of the Galaxy is the investigation of stellar populations and Galactic chemical evolution by stellar spectroscopy. Due to the dust obscuration in the line-of-sight, stars in the plane and toward the centre of the Galaxy can only be observed in the near-IR wavelength region. Important questions can thus be addressed by observing stars in the near-IR, a field that is in r

Context. Effective temperature is one of the fundamental stellar parameters. A traditional spectroscopic way to determine it is from optical spectra using excitation balance of Fe-lines. With technological advances and the advent of the next generation telescopes there will be an emphasis on the relatively unexplored near-IR (NIR) wavelength region (1-5 μm). A method to determine the effective tem

Researchers in the field of Galactic Archaeology have entered the era of industrial revolution. Upcoming surveys are planning on observing tens of millions of stars and high precision and accuracy must be ensured when deriving their stellar parameters and elemental abundances. Unconventional data-driven techniques hold the promise of efficiently dealing with these vast collections of data while st

In this thesis we add a temperature dependence to the newly developed variable polytrope equation of state (Varpoly EOS) from Weppner et al. (2015), making it more universal and more applicable for planetary simulations. In this process we develop a new model for the Gruneisen parameter, which is a parameter that describes how pressure changes with the internal energy. This new model conforms to t

For testing three-dimensional (3D) hydrodynamic models of stellar atmospheres, spectroscopy across spatially resolved stellar surfaces with high spectral resolution is desired. 3D models predict center-to-limb changes in asymmetries, shapes, strengths and wavelength positions of spectral line profiles, reflecting the hydrodynamics of the stellar atmosphere. However, except for a few supergiants an