Fe K emission from the hidden quasar IRAS P09104+4109

A. C. Fabian, Y. Shioya, K. Iwasawa, K. Nandra, C. Crawford, R. Johnstone, H. Kunieda, R. Mcmahon, K. Makishima, T. Murayama, T. Ohashi, Y. Tanaka, Y. Taniguch̀i, Y. Terashima

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17 Citations (Scopus)


We report the discovery of a strong Fe K line in the ASCA spectrum of the infrared-luminous galaxy IRAS P09104+4109 at a redshift z = 0.442. It is the most distant Fe K emission line detected so far. The large equivalent width (EW ∼ 450 eV) and X-ray continuum spectrum, which has Γ ≈ 2.0 with little absorption, favors a model in which the observed X-rays are scattered into our line of sight from a hidden quasar. Previous work has shown that the source has strong narrow emission lines and a highly polarized continuum in the optical and a strong infrared excess, similar to Seyfert 2 galaxies. The observed X-ray luminosity is LX ≈ 2 x 1045 ergs s-1 in the rest frame 2-10 keV band; the large obscuration suggested by the optical and infrared studies implies that the hidden quasar has an intrinsic luminosity of LBol = 5 x 1047 ergs s-1. Our results indicate that IRAS P09104+4109 is the prototype of a new class of Seyfert 2 nuclei, which emit at quasar luminosities.

Original languageEnglish
Pages (from-to)L51-L54
JournalAstrophysical Journal
Issue number1 PART 2
Publication statusPublished - 1994 Nov 20


  • Galaxies: active
  • X-rays: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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