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This thesis examines the loss of social media during incarceration and how incarcerated individuals reflect on the abrupt absence of social media in their lives. Based upon eight interviews with previously incarcerated individuals, this thesis studies the emotional process incarcerated people go through when doing identity work. Building upon Erving Goffman’s framework of identity and self-present
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
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
This is a bachelor thesis bent on introducing the field of exoplanet research. It primarily includes descriptions of the various detection methods, with some detail into how the methods yield parameter estimates by means of least-squares algorithms. The feasibility of combining state-of-the-art astrometric capabilities of Gaia and radial velocity measurements from ground level is briefly discussed
Imaging of stellar surfaces in visible wavelengths is one of the current frontiers in astronomy. With a few exceptions, stars can not be seen in visible light as anything but point objects with current technology. Being able to properly image stars would open up the door to a vast field of new discoveries, permitting direct studies of phenomena such as rotationally deformed stars, circumstellar di
We investigate the radial infall of ice pebbles in a protoplanetary disk, and how these tend to end up in relatively close proximity to eachother, providing a possible spawning ground for planets. These pebbles have dust particles embedded in them, which are released as the pebble crosses the so-called ice- line, where the ice evaporates. This is interesting as the dust will pile up around this ic
We test a new approach to calculate the mean velocity and velocity dispersion for a sample of nearby stars when their radial velocities are not available. The most commonly used method (here called the projection method, PM) was introduced in a paper by Dehnen & Binney (1998). That method is here compared, theoretically and numerically, with an application of the Maximum Likelihood (ML) method
Most of the things that we know about stars come from their spectrum. The properties of the atomic lines, e.g. energy levels, wavelengths, oscillator strengths, must be known to understand the observed spectrum and to perform quantitative analyses. Atomic data of some elements are incomplete, especially in the near-infrared region, which makes it difficult or even impossible to analyze a stellar s
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
A selection of well known period luminosity relations for cepheid variables are studied under the assumption that cepheid variables have a mean vertical velocity of zero in the galactic plane. Proper motion data from Hipparcos and Thyco-2 catalogues are coupled with the distances obtained from applying the period luminosity relations on a database of known classical cepheids to calculate the veloc
In this project I have studied the effect of gas expulsion on the evolution of stellar clusters. What effect the rate of gas removal and the quantity of gas removed has on the evolution on the cluster will be studied through computer simulations with the NBody6 code and compared to analytical predictions. The rate at which gas is removed has a very significant impact on how the cluster evolves
Where the dust in a protoplanetary disk is as the disk evolves over time is essential to know for further studies of the planet formation process. A new star is created alongside a stellar nebula. The nebula contains rock, ice and gas which are not accreted to the star. Our nebula is constructed using the Minimum Mass Solar Nebula model and the column density is studied as the protoplanetary disk
This is an analysis of all the planets at exoplanets.org, with the goal of finding out how many of these that could possibly have moons supporting life. I have first calculated the ranges of the habitable zones (HZ:s) for the stars in the archive, using the Runaway Greenhouse model for the inner limit, and the Maximum Greenhouse model for the outer limit, as presented by Kopparapu et al. (2013A).
