Sökning: "luminosities"

Visar resultat 1 - 5 av 16 avhandlingar innehållade ordet luminosities.

1. 1. A Photometric Study of the Galactic Disks based on Strömgren Photometry

   Författare :Anna Arnadottir; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density parameters; formation.; metallicity distribution function; thin disk; metallicities. Galaxy - thick disk; colours; Photometry - Strömgren; luminosities; SDSS. Stars - classification;

   Sammanfattning : One of the key questions in todays galaxy research is the formation and evolution of disk galaxies such as the Milky Way. Using observations in the intermediate band Stromgren uvby filter system we have investigated how both density and metallicity varies within the Galactic disks in order to learn more about the Galaxy and its past. LÄS MER

3. 2. Measurements of the Top Quark Pair Production Cross Section and an Estimate of the DØ Silicon Detector Lifetime

   Författare :Sara Strandberg; Christophe Clément; Barbro Åsman; Steinar Stapnes; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; particle physics; top quark pair production cross section; silicon radiation damage; DØ detector; Tevatron accelerator; Elementary particle physics; Elementarpartikelfysik; Physics; fysik;

   Sammanfattning : This thesis presents two measurements of the top quark pair production cross section at sqrt{s} = 1.96 TeV using data from the DØ experiment. Both measurements are performed in the dilepton final state and make use of secondary vertex b-tagging. LÄS MER

4. 3. Molecular observations of obscured galaxy nuclei

   Författare :Niklas Falstad; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxies: nuclei; Galaxies: ISM; Infrared: galaxies; ISM: Molecules; Submillimeter: galaxies;

   Sammanfattning : It is becoming evident that some (ultra)luminous infrared galaxies ((U)LIRGs) contain compact obscured nuclei (CONs) where luminosities in excess of 10^9 L☉  emerge from inside dusty regions smaller than 100 pc in diameter. Due to the obscured nature of these objects, their inner regions are hidden from examination using optical or infrared lines. LÄS MER

5. 4. Aspects of quarks in exotic matter

   Författare :Daniel Enström; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Fysik;

   Sammanfattning : In this licentiate thesis, two different aspects of particle physics have been studied. The results are presented in four papers. In papers I and II, a model for a joint origin of gamma-ray bursts and dark matter is presented. The common denominator is the deconfined state of quarks, the Quark-Gluon Plasma (QGP). LÄS MER

7. 5. ATLAS Pixel Detector Readout Integrated Circuits and Data Acquisition

   Författare :Veronica Wallängen; Samuel Silverstein; Sara Strandberg; Maurice Garcia-Sciveres; Jacob Wikner; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysik; Physics;

   Sammanfattning : The Large Hadron Collider (LHC) is a particle collider built by CERN for testing the predictions of theories within high energy physics, thereby contributing to advancements in our understanding of physical laws. In order to improve the discovery potential of the collider, the LHC will undergo an upgrade to be able to reach luminosities of 5x1034 cm2s-1 and the increased collision rate following the upgrade facilitates the need for a new readout system for the ATLAS experiment at the LHC that meets the challenging demands on low mass, high-speed readout capability and radiation tolerance, something which is especially important for the pixel detector closest to the particle interaction point. LÄS MER