Sökning: "Dwarf Galaxies"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden Dwarf Galaxies.

1. 1. Star-forming Dwarf Galaxies : Internal motions and evolution

   Författare :Thomas Marquart; Nils Bergvall; Janice Lee; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxy; Galaxies; Dynamics; Kinematics; Starburst; Dwarf Galaxies; Blue Compact Galaxies; Star Formation; Galaxy mergers; 3D-Spectroscopy; Spectroscopy; Astronomy; Astronomi;

   Sammanfattning : The study of dwarf galaxies is important in order to better understand the physics of the young universe and how larger galaxies form and evolve. In this work we focus on Blue Compact Galaxies (BCGs) which havemuch enhanced star formation (starbursts), causing blue colours and strong emission line spectra. LÄS MER

3. 2. Dark matter signal normalisation for dwarf spheroidal galaxies : A frequentist analysis of stellar kinematics for indirect Dark Matter searches

   Författare :Andrea Chiappo; Jan Conrad; Piero Ullio; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dark matter; dwarf galaxies; kinematics and dynamics of galaxies; fysik; Physics;

   Sammanfattning : Indirect detection strategies of Dark Matter (DM) entail searching for signals of DM annihilation or decay, typically in the form of excess positrons or high-energy photons above the astrophysical background, originating from (inferred) DM-rich environments. Due to their characteristics, dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are considered very promising targets for indirect particle DM identification. LÄS MER

4. 3. On the origin and evolution of blue compact galaxies

   Författare :Göran A. Östlin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; galaxies - compact; formation; evolution; starburst; interactions; dwarf; photometry; kinematics and dynamics; low surface brightness galaxies; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

   Sammanfattning : This thesis is focused on the origin and evolution of blue compact galaxies (BCGs). BCGs are low mass galaxies characterised by blue colours, low chemical abundances and high star formation rates. The gas consumtion time scale is considerable shorter than the age of the universe and thus the high star formation rate must be transient. LÄS MER

5. 4. Photometry of Resolved Stellar Populations in Local Group Galaxies

   Författare :Daniel Faria; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomi; Astronomy; Local Group; Galaxy: halo; Galaxies: dwarf; Galaxy: stellar content; Galaxies: photometry; Techniques: photometric; Stars: fundamental parameters;

   Sammanfattning : This thesis presents results from two projects using photometric observations to investigate stellar populations in Local Group galaxies. In the first project, Strömgren photometry is used to study stellar populations in dwarf spheroidal galaxies. LÄS MER

7. 5. On the Escape of Lyman Radiation from Local Galaxies

   Författare :Elisabet Leitet; Nils Bergvall; Erik Zackrisson; Bengt Gustafsson; Duilia F. De Mello; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxies; starbursts; spiral galaxies; Lyman continuum; Lyman alpha; leakage; cosmic reionization; escape fraction; Astronomy; Astronomi;

   Sammanfattning : Cosmic reionization was most likely initiated by star forming dwarf galaxies. Little is known about the physical mechanisms allowing ionizing Lyman continuum (LyC) photons to escape from galaxies, but to learn more we can study local galaxies in detail. LÄS MER