ISSN:
1476-4687
Source:
Nature Archives 1869 - 2009
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
Notes:
[Auszug] Supermassive black holes underwent periods of exponential growth during which we see them as quasars in the distant Universe. The summed emission from these quasars generates the cosmic X-ray background, the spectrum of which has been used to argue that most black-hole growth is obscured. There ...
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1038/nature03829
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