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Spitzer Infrared Spectrograph (IRS)* Observations of the Redshift 3.91 Quasar APM 08279+5255
The Astrophysical Journal (2004)
  • B. T. Soifer, California Institute of Technology
  • V. Charmandaris, Cornell University
  • B. R. Brandl, Cornell University
  • L. Armus, California Institute of Technology
  • P. N. Appleton, California Institute of Technology
  • M. J. Burgdorf, California Institute of Technology
  • D. Devost, Cornell University
  • T. L. Herter, Cornell University
  • Sarah J.U. Higdon, Cornell University
  • J. L. Higdon, Cornell University
  • J. R. Houck, Cornell University
  • C. R. Lawrence, California Institute of Technology
  • P. W. Morris, California Institute of Technology
  • H. I. Teplitz, California Institute of Technology
  • K. I. Uchida, Cornell University
  • J. van Cleve, Cornell University
  • D. Weedman, Cornell University
The Infrared Spectrograph ( IRS) on board the Spitzer Space Telescope has been used to obtain low- and moderate-resolution spectra of the dust- and gas-rich quasar APM 08279+5255 (z ¼ 3:91). Broad Pa and Pa recombination lines of hydrogen were detected at wavelengths of 9.235 and 6.315 m, respectively, as well as a strong, red continuum that is a smooth power law over the observed (rest-frame) wavelength range 5.3–35 m (1.08–7.1 m). The observed Pa/ Pa line flux ratio of 1:05  0:2 is far from the case B value of 2 and simple models of high-density, high optical depth ionized-gas regions (1.8). This deviation is opposite in sense to the expected effect of reddening. No evidence is found in the spectrum for either the 3.3 or the 6.2 m emission features usually attributed to aromatic hydrocarbons in gas-rich galaxies in the local universe. This is consistent with the high-luminosity active galactic nucleus (AGN ) nature of APM 08279+5255. Subjec
  • Galaxies,
  • High-redshift,
  • Quasars,
  • Emission Lines,
  • Individual,
  • APM 08279+5255,
  • Techniques,
  • Spectroscopic
Publication Date
September, 2004
Publisher Statement
This version of the paper was obtained from In order for the work to be deposited in, the author must have copyright or it must be available under the Creative Commons Attribution license, Creative Commons Attribution-Noncommercial-ShareAlike license, orCreate Commons Public Domain Declaration. The publisher's final edited version of this article will be available at The Astrophysical Journal.
Citation Information
B. T. Soifer, V. Charmandaris, B. R. Brandl, L. Armus, et al.. "Spitzer Infrared Spectrograph (IRS)* Observations of the Redshift 3.91 Quasar APM 08279+5255" The Astrophysical Journal Vol. 154 Iss. 1 (2004) p. 151 - 154
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