University of Hertfordshire

From the same journal

From the same journal

A 3 x 10 solar mass black hole in the quasar SDSS J1148+5251 at z=6.41

Research output: Contribution to journalArticle


  • C.J. Willott
  • R.J. McLure
  • M.J. Jarvis
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Original languageEnglish
Pages (from-to)L15-L18
JournalThe Astrophysical Journal
Journal publication date2003
Publication statusPublished - 2003


We present near-infrared H- and K-band spectra of the z p 6.41 quasar SDSS J114816.64 525150.3. The spectrum reveals a broad Mg ii l2799 emission line with an FWHM of 6000 km s 1. From the peak wavelength of this emission line, we obtain a more accurate redshift than is possible from the published optical spectrum and determine a redshift of z p 6.41 0.01. If the true peak of the Lya emission is at the same redshift, then a large fraction of the flux blueward of the peak is absorbed. The equivalent width of the Mg ii emission line is similar to that of lower redshift quasars, suggesting that the UV continuum is not dominated by a beamed component. Making basic assumptions about the line-emitting gas, we derive a mass estimate of M, 3#109 for the central black hole in this quasar. The very high luminosity of the quasar shows that it is accreting at the maximal allowable rate for a black hole of this mass, adopting the Eddington limit criterion.


Original article can be found at: Copyright American Astronomical Society

ID: 178427