The spectral energy distribution of the z = 3 quasar: HS 1946+7658

O. Kuhn, J. Bechtold, R. Cutri, M. Elvis, M. Rieke

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11 Scopus citations


For the bright z = 3.02 radio-quiet quasar, HS 1946+7658, we have obtained radio to X-ray data within the past year: 5 GHz and 1415 MHz data from the VLA; IR photometry at J, H, K, L′ (3.4 μm) and N; IR spectroscopy; UBVRI photometry; optical spectrophotometry and high-resolution spectra; and an X-ray spectrum from the ROSAT PSPC. The spectral energy distribution (SED) constructed from these data is compared to the mean SED for a set of low-redshift quasars, and while.they appear generally similar, there are several differences. In relation to the low-redshift mean, the SED of HS 1946+7658 shows (1) only an upper limit at 10 μm (a rest wavelength of 2.5 μm), indicating that HS 1946+7658 does not have a strong near-IR excess such as hot dust would produce; (2) relatively weak Fe II and Balmer continuum emission at ∼3000 Å; and (3) a steeper turndown shortward of Lyα, even after correction for the Lyα forest absorption lines.

Original languageEnglish (US)
Pages (from-to)643-649
Number of pages7
JournalAstrophysical Journal
Issue number2
StatePublished - Jan 10 1995


  • Radio continuum: galaxies
  • X-rays: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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