Deep XMM-Newton Observations of an X-ray Weak Broad Absorption Line Quasar at z = 6.5

Jinyi Yang, Xiaohui Fan, Feige Wang, Giorgio Lanzuisi, Riccardo Nanni, Massimo Cappi, George Chartas, Mauro Dadina, Roberto Decarli, Xiangyu Jin, Charles R. Keeton, Bram P. Venemans, Fabian Walter, Ran Wang, Xue Bing Wu, Minghao Yue, Ann Zabludoff

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


We report X-ray observations of the most distant known gravitationally lensed quasar, J0439+1634 at z = 6.52, which is also a broad absorption line (BAL) quasar, using the XMM-Newton Observatory. With a 130 ks exposure, the quasar is significantly detected as a point source at the optical position with a total of net counts using the EPIC instrument. By fitting a power law plus Galactic absorption model to the observed spectra, we obtain a spectral slope of . The derived optical-to-X-ray spectral slope a ox is , suggesting that the X-ray emission of J0439+1634 is weaker by a factor of 18 than the expectation based on its 2500 Å luminosity and the average a ox versus luminosity relationship. This is the first time that an X-ray weak BAL quasar at z > 6 has been observed spectroscopically. Its X-ray weakness is consistent with the properties of BAL quasars at lower redshift. By fitting a model including an intrinsic absorption component, we obtain intrinsic column densities of and , assuming a fixed G of 1.9 and a free G, respectively. The intrinsic rest-frame 2-10 keV luminosity is derived as (9.4-15.1) 1043 erg s-1, after correcting for lensing magnification (µ = 51.3). The absorbed power-law model fitting indicates that J0439+1634 is the highest redshift obscured quasar with a direct measurement of the absorbing column density. The intrinsic high column density absorption can reduce the X-ray luminosity by a factor of 3-7, which also indicates that this quasar could be a candidate intrinsically X-ray weak quasar.

Original languageEnglish (US)
Article numberL25
JournalAstrophysical Journal Letters
Issue number2
StatePublished - Jan 10 2022
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Deep XMM-Newton Observations of an X-ray Weak Broad Absorption Line Quasar at z = 6.5'. Together they form a unique fingerprint.

Cite this