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Updated: Jul 12, 2026

Demonstration of a Hyperlens-integrated Microscope and Super-resolution Imaging
Published on: September 8, 2017
Magnification of light from many distant quasars by gravitational lenses
J Stuart B Wyithe1, Abraham Loeb
1Astronomy Department, Harvard University, 60 Garden Street, Cambridge, Massachusetts 02138, USA.
Abstract:
Exceptionally bright quasars with redshifts up to z = 6.28 have recently been discovered. Quasars are thought to be powered by the accretion of gas onto supermassive black holes at the centres of galaxies. Their maximum (Eddington) luminosity depends on the mass of the black hole, and the brighter quasars are inferred to have black holes with masses of more than a few billion solar masses. The existence of such massive black holes poses a challenge to models for the formation of structures in the early Universe, as it requires their formation within one billion years of the Big Bang. Here we show that up to one-third of known quasars with z approximately equal to 6 will have had their observed flux magnified by a factor of ten or more, as a consequence of gravitational lensing by galaxies along the line of sight. The inferred abundance of quasar host galaxies, as well as the luminosity density provided by the quasars, has therefore been substantially overestimated.
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