Sökning: "galaxy : disc"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden galaxy : disc.

1. 1. Exploring the nature of ISM turbulencein disc galaxies

   Författare :Timmy Ejdetjärn; Göran Östlin; Oscar Agertz; Garrelt Mellema; Troels Haugbølle; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; galaxies; galaxy; disc galaxy; star formation; ISM; interstellar medium; kinematics; dynamics; evolution; turbulence; numerical; Astronomy; astronomi; teoretisk astrofysik; Theoretical Astrophysics;

   Sammanfattning : Galaxy formation is a continuous process that started only a few hundred million yearsafter the Big Bang. The first galaxies were very volatile, with bursts of star formationand disorganised gas motions. LÄS MER

3. 2. Stellar Ages for Galactic Archaeology : Methods and Applications

   Författare :Christian Sahlholdt; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxy : formation; Stellar ages; Milky Way Galaxy; Low mass stars; Galaxy : disc; Galaxy : evolution; Fysicumarkivet A:2021:Sahlholdt;

   Sammanfattning : Galactic Archaeology is the study of the formation and evolution of the Milky Way through the properties of stars and stellar populations. The combination of stellar ages, chemical compositions, positions, and velocities can reveal the history of star formation and chemical enrichment in different regions of the Galaxy. LÄS MER

4. 3. The nature of kinematic structures in the Galactic disc

   Författare :Iryna Kushniruk; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxy : evolution; Galaxy: structure; Galaxy : kinematics and dynamics;

   Sammanfattning : The velocity distribution of stars in the Galactic disc is complex and consists of a vast number of kinematic structures, that is, stars that share similar velocity components. The reasons why some stars move together may be different and are related to dynamical processes connected to the Galaxy, both internal as well as external ones, such as resonances with the Galactic bar or the Galactic spiral arm structure, dissolution of open clusters, or merger events with other galaxies. LÄS MER

5. 4. Rearrangement of gas in disc galaxies

   Författare :Núria Piñol Ferrer; Kambiz Fathi; Santiago Garcia-Burillo; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi;

   Sammanfattning : Active galactic nuclei and bursts of star formation are two distinct phenomena that amply change their host environments. They are present in a significant number of galaxies at all redshifts. In this thesis, we aim toward a better understanding of the physical processes that allow for the formation and maintenance of these two phenomena. LÄS MER

7. 5. Transfer of Angular Momentum in Astrophysical Discs

   Författare :Mattias Wahde; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : In this thesis a study of astrophysical discs, with emphasis on galactic discs, is presented. The frictional force acting on a small satellite galaxy, moving on a co-planar circular orbit in a galactic disc, is shown to be only weakly dependent on the velocity dispersion and the self-gravity of the disc. LÄS MER