Sökning: "dark matter halos"
Visar resultat 1 - 5 av 9 uppsatser innehållade orden dark matter halos.
1. Void Evolution and Cosmic Star Formation
Kandidat-uppsats, Uppsala universitet/Institutionen för fysik och astronomiSammanfattning : The rate at which stars have formed throughout the history of theuniverse is not constant, it started out slow, increased until around redshift ∼ 2 when it reversed and became slower again. The reason for this behaviour is still being investigated with various models and simulations usually based upon dark matter halos. LÄS MER
2. Starbursts at Cosmic Dawn : Formation of Globular Clusters, Ultra-Faint Dwarfs, and Population III star clusters at z > 6
Master-uppsats, Stockholms universitet/Institutionen för astronomiSammanfattning : In the standard model of cosmology (ΛCDM) the first stars, star clusters, and galaxies are expected to have formed in short bursts of star formation in low-mass dark matter halos at high redshifts (). Up to this point, attempts to predict the properties and abundances of these luminous objects have made use of numerically expensive cosmological simulations. LÄS MER
3. The spatial distribution of dark matter in the Universe
Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisationSammanfattning : It was previously found that the density profile of dark matter halos is well-fit by a universal, smooth function over a vast range of masses and redshifts, named the Navarro-Frenk-White (NFW) profile after its discoverers. Despite its impressive goodness of fit, the NFW model remains an approximation of the density profile of realistic halos. LÄS MER
4. An introduction to some ordinary differential equations governing stellar structures
Kandidat-uppsats, Lunds universitet/Matematik (naturvetenskapliga fakulteten)Sammanfattning : The Lane-Emden equation is a non-linear differential equation governing the equilibrium of polytropic stationary self-gravitating, spherically symmetric star models; $${\frac {1}{\xi ^{2}}}{\frac {d}{d\xi }}\left({\xi ^{2}{\frac {d\theta }{d\xi }}}\right)+\theta ^{n}=0.$$ In the isothermal cases we have the Chandrasekhar equation: $${\frac {1}{\xi ^{2}}}{\frac {d}{d\xi }}\left({\xi ^{2}{\frac {d\psi}{d\xi }}}\right)-e^{-\psi}=0$$ After having derived these models, we will go through all cases for which analytic solutions are achievable. LÄS MER
5. Radial migration of stars, measured in N-body simulations
Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation; Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisationSammanfattning : 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. LÄS MER
