ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Weitere Quellen  (3)
  • Sonstige Sternensysteme {Astronomie}  (3)
  • Univ. Potsdam  (3)
  • Geologisches Institut 〈Freiberg〉
  • Englisch  (3)
  • Französisch
Sammlung
  • Weitere Quellen  (3)
Datenquelle
Verlag/Herausgeber
Sprache
  • Englisch  (3)
  • Französisch
Erscheinungszeitraum
  • 1
    facet.materialart.
    Unbekannt
    Univ. Potsdam
    Publikationsdatum: 2021-03-29
    Beschreibung: The intergalactic medium is kept highly photoionised by the intergalactic UV background radiation field generated by the overall population of quasars and galaxies. In the vicinity of sources of UV photons, such as luminous high-redshift quasars, the UV radiation field is enhanced due to the local source contribution. The higher degree of ionisation is visible as a reduced line density or generally as a decreased level of absorption in the Lyman alpha forest of neutral hydrogen. This so-called proximity effect has been detected with high statistical significance towards luminous quasars. If quasars radiate rather isotropically, background quasar sightlines located near foreground quasars should show a region of decreased Lyman alpha absorption close to the foreground quasar. Despite considerable effort, such a transverse proximity effect has only been detected in a few cases...
    Beschreibung: thesis
    Schlagwort(e): 523 ; 550 ; TIE 400 ; TIE 900 ; Sonstige Sternensysteme {Astronomie} ; Spektren und Leuchtkraft von Sternsystemen {Astronomie}
    Sprache: Englisch
    Materialart: monograph , publishedVersion
    Format: 144 S.
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    facet.materialart.
    Unbekannt
    Univ. Potsdam
    Publikationsdatum: 2021-03-29
    Beschreibung: Giacconi et al. (1962) discovered a diffuse cosmic X-ray background with rocket experiments when they searched for lunar X-ray emission. Later satellite missions found a spectral peak in the cosmic X-ray background at ~30 keV. Imaging X-ray satellites such as ROSAT (1990-1999) were able to resolve up to 80% of the background below 2 keV into single point sources, mainly active galaxies. The cosmic X-ray background is the integration of all accreting super-massive (several million solar masses) black holes in the centre of active galaxies over cosmic time. Synthesis models need further populations of X-ray absorbed active galaxy nuclei (AGN) in order to explain the cosmic X-ray background peak at ~30 keV. Current X-ray missions such as XMM-Newton and Chandra offer the possibility of studying these additional populations...
    Beschreibung: thesis
    Schlagwort(e): 523 ; 550 ; TBK 000 ; TIE 900 ; Hochenergieastronomie ; Sonstige Sternensysteme {Astronomie}
    Sprache: Englisch
    Materialart: monograph , publishedVersion
    Format: 226 S.
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    facet.materialart.
    Unbekannt
    Univ. Potsdam
    Publikationsdatum: 2021-03-29
    Beschreibung: Strong damped Lyman alpha absorption (DLA) lines seen spectra of distant quasar are believed to arise when the sight line to the quasar goes trough the disc of a galaxy or a proto galaxy. Most of the neutral matter in the universe is contained in these clouds of neutral hydrogen that cause the absorption lines. Hence these DLAs are reservoirs for the formation of stars and galaxies throughout the universe. Despite intensive efforts over more than two decades only few galaxies responsible for the DLAs have been found. The problem is that the galaxies that harbour the neutral clouds are not necessarily bright, and selecting galaxies based on absorption lines could well select different types of galaxies than found in large surveys. If we are to understand how galaxies form out of neutral gas clouds it is essential to locate the galaxies in which DLAs reside ...
    Beschreibung: thesis
    Schlagwort(e): 523 ; TIE 900 ; TIE 400 ; Sonstige Sternensysteme {Astronomie} ; Spektren und Leuchtkraft von Sternsystemen {Astronomie}
    Sprache: Englisch
    Materialart: monograph , publishedVersion
    Format: 187 S.
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...