The Broadband Spectral Energy Distributions of the Cloverleaf Quasar and IRAS F10214+4724

Abstract

We have constructed broadband spectral energy distributions for the Cloverleaf quasar (z = 2.56) and the luminous infrared galaxy IRAS F10214+4724 (z = 2.28). These are to date the only two high-redshift objects known with measured thermal far-infrared spectra and the only two with solid millimeter-wave detections of molecular gas. The continuum data are assembled from the literature, from a new analysis of IRAS measurements, and from new measurements in the near-infrared, optical, and at 1.25 mm. The spectral shapes and luminosities of the two objects are nearly identical from the rest submillimeter to 20 μm, but they diverge dramatically in the optical/ultraviolet. A simple unifying obscuration/reflection model is presented that may explain the differences. Considering their very similar molecular gas content, together with evidence based on the continuum energy distributions and optical spectropolarimetry, it appears quite plausible that the Cloverleaf and F10214+4724 in fact differ for the most part only in their orientations with respect to Earth.