Sökning: "Binaries: close"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Binaries: close.

  1. 1. Theoretical Studies of Binaries in Astrophysics

    Författare :Johann Dischler; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomi; Astronomy; Galaxy: centre; Stars: mass-loss; Binaries: close; Binaries: eclipsing;

    Sammanfattning : This thesis introduces and summarizes four papers dealing with computer simulations of astrophysical processes involving binaries. The first part gives the rational and theoretical background to these papers. In paper I and II a statistical approach to studying eclipsing binaries is described. LÄS MER

  3. 2. X-ray variability in Galactic high-mass black hole binaries

    Författare :Magnus Axelsson; Stefan Larsson; Chris Done; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Accretion; high-energy astrophysics; temporal variability; X-ray binaries; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; astronomi;

    Sammanfattning : The stars of the night sky can to the naked eye appear to be steady and unchanging, apart from the twinkling created by air moving in the atmosphere. However, when viewed in X-rays, the sky is far from constant, with detectable changes occurring on very short timescales.Black hole X-ray binaries are strong sources of X-rays. LÄS MER

  4. 3. Studies of the S-type AGB star W Aquilae : The circumstellar envelope and the fain companion

    Författare :Taissa Danilovich; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stars: binaries: spectroscopic; circumstellar matter; stars: binaries: visual; stars: evolution; stars: mass-loss; stars: AGB and post-AGB; stars: individual: W Aql;

    Sammanfattning : Low- and intermediate-mass stars will all eventually enter the asymptotic giant branch (AGB) phase. AGB stars experience intense mass-loss, generating a significant fraction of the dust and molecular matter that enrichesthe ISM. AGB stars are also responsible for a the production of about half of all elements heavier than iron. LÄS MER

  5. 4. Studies of Gas Disks in Binary Systems

    Författare :Miguel de Val Borro; Pawel Artymowicz; William Benz; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Astronomy; Astronomi; Astronomy; astronomi;

    Sammanfattning : There are over 300 exoplanets detected through radial velocity surveys and photometric studies showing a tremendous variety of masses, compositions and orbital parameters. Understanding the way these planets formed and evolved within the circumstellar disks they were initially embedded in is a crucial issue. LÄS MER

  7. 5. Optical and Electronic Properties of WO3 and Zn Chalcogenides Alloys: A Theoretical study

    Författare :Gustavo Baldissera; Clas Persson; Naoto Umezawa; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Material and Nano Physics; Material- och nanofysik;

    Sammanfattning : I denna avhandling analyseras optiska och elektroniska egenskaper hos WO3 och Zn-relaterade legeringar med hjälp av täthetsfunktionalteori (DFT). Metoder som går utöver DFT, såsom GW-approximationen och hybridfunktionaler, används för att minimera det fel som genereras av det smala bandgapet som erhålls med konventionella DFT-funktionaler. LÄS MER