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The age of the quasars

An infrared census of accreting supermassive black holes across a wide range of cosmic times indicates that the canonical understanding of how these luminous objects form and evolve may need to be adjusted.

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Figure 1: The energy output of quasars over cosmic time.


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Correspondence to Daniel Mortlock.

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Mortlock, D. The age of the quasars. Nature 514, 43–44 (2014).

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