English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Merging the Chandra and XMM-Newton deep surveys with the previouslyidentified ROSAT sample, almost 1000 AGN-1 covering five orders of magnitude in0.5-2 keV flux limit and six orders of magnitude in survey solid angle wereidentified with ~95% completeness. AGN-1 are by far the largest contributors tothe soft X-ray samples. Their evolution is responsible for the break in the0.5-2 keV source counts. Their soft X-ray luminosity function clearly changesshape as a function of redshift, confirming earlier reports ofluminosity--dependent density evolution. The space density with redshiftchanges significantly for different luminosity classes, showing a strongpositive evolution up to a certain redshift and then a flattening. Theredshift, at which the evolution peaks, changes considerably with X-rayluminosity. The amount of density evolution also depends strongly on X-rayluminosity, more than a factor of 100 at high luminosities, but less than afactor of 10 for low luminosities. For the first time, a significant decline ofthe space density of X-ray selected AGN towards high redshift has beendetected. No significant evolution of the X-ray to optical spectral index isfound for AGN-1. The constraints from the AGN luminosity function and evolutionin comparison with the mass function of black holes in local galaxiesindicates, that the average supermassive black hole has built up its massthrough efficient accretion and is likely rapidly spinning.Comment: Proceedings of the Conference "Growing Black Holes"; A. Merloni, S.  Nayakshin and R. Sunyaev (eds.

When Supermassive Black Holes Were Growing: Clues from Deep X–ray Surveys