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Article
First Mid-Infrared Spectrum of a Faint High-z Galaxy: Observations of CFRS 14.1157 with the Infrared Spectrograph* on the Spitzer Space Telescope **
The Astrophysical Journal (2004)
  • Sarah J.U. Higdon, Cornell University
  • D. Weedman, Cornell University
  • J. L. Higdon, Cornell University
  • T. L. Herter, Cornell University
  • V. Charmandaris, Cornell University
  • J. R. Houck, Cornell University
  • B. T. Soifer, California Institute of Technology
  • B. R. Brandl, Leiden University
  • L. Armus, California Institute of Technology
  • L. Hao, Cornell University
Abstract
The unprecedented sensitivity of the Infrared Spectrograph on the Spitzer Space Telescope allows for the first time the measurement of mid-infrared spectra from 14 to 38 m of faint high-z galaxies. This unique capability is demonstrated with observations of sources having 16 m fluxes of 3.6 mJy (CFRS 14.1157) and 0.35 mJy (CFRS 14.9025). A spectral-fitting technique is illustrated that determines the redshift by fitting emission and absorption features characteristic of nearby galaxies to the spectrum of an unknown source. For CFRS 14.1157, the measured redshift is z ¼ 1:00  0:20, in agreement with the published result of z ¼ 1:15. The spectrum is dominated by emission from an active galactic nucleus, similar to the nucleus of NGC 1068, rather than a typical starburst with strong polycyclic aromatic hydrocarbon emission like M82. Such spectra will be crucial in characterizing the nature of newly discovered distant galaxies, which are too faint for optical follow-up.
Keywords
  • Dust,
  • Extinction,
  • Galaxies,
  • Active,
  • High-redshift,
  • Individual,
  • CFRS 14.1157,
  • CFRS 14.9025,
  • CFRS 14.1129,
  • Starburst,
  • Infrared
Publication Date
September, 2004
DOI
10.1086/422218
Publisher Statement
This version of the paper was obtained from arXIV.org. In order for the work to be deposited in arXIV.org, 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
Sarah J.U. Higdon, D. Weedman, J. L. Higdon, T. L. Herter, et al.. "First Mid-Infrared Spectrum of a Faint High-z Galaxy: Observations of CFRS 14.1157 with the Infrared Spectrograph* on the Spitzer Space Telescope **" The Astrophysical Journal Vol. 154 Iss. 1 (2004) p. 174 - 177
Available at: http://works.bepress.com/sarah_higdon/29/