So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered1,2,3,4,5,6,7,8. Each quasar contains a black hole with a mass of about one billion solar masses (109 )2,6,7,9,10,11,12,13. The existence of such black holes when the Universe was less than one billion years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies14. Here we report the discovery of an ultraluminous quasar, SDSS J010013.02+280225.8, at redshift z = 6.30. It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. On the basis of the deep absorption trough15 on the blue side of the Lyman-α emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 6.1 quasars with lower luminosities16. We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of ∼1.2 × 1010 , which is consistent with the 1.3 × 1010 derived by assuming an Eddington-limited accretion rate.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
X.-B.W. thanks the NSFC (grant nos 11033001 and 11373008), the Strategic Priority Research Program ‘The Emergence of Cosmological Structures’ of the Chinese Academy of Sciences (grant no. XDB09000000), and the National Key Basic Research Program of China (grant no. 2014CB845700) for support. X.F., R.W. and I.D.M. thank the US NSF (grant nos AST 08-06861 and AST 11-07682) for support. R.W. thanks the NSFC (grant no. 11443002) for support. We acknowledge the support of the staff of the Lijiang 2.4-m telescope. Funding for the telescope was provided by the Chinese Academy of Sciences and the People’s Government of Yunnan Province. This research uses data obtained through the Telescope Access Program (TAP), which has been funded by the Strategic Priority Research Program ‘The Emergence of Cosmological Structures’ (grant no. XDB09000000), National Astronomical Observatories, Chinese Academy of Sciences, and the Special Fund for Astronomy from the Ministry of Finance of China. We thank D. Osip for help with Magellan/FIRE spectroscopy, and Y.-L. Ai, L. C. Ho, Y. Shen and J.-G. Wang for suggestions about data analyses. We acknowledge the use of SDSS, 2MASS and WISE data, and of the MMT, LBT, Gemini and Magellan telescopes; detailed acknowledgments of these facilities can be found in Supplementary Information.
Extended data figures
This file contains additional acknowledgments.
About this article
Scientific Reports (2017)