Paul J. Coleman

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

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.

IONIZING RADIATION DETECTED BY PIONEER II

The total ionizing component of cosmic radiation was measured up to an altitude of 1550 km. An upper bound to the ratio of average-to-minimum specific ionization was determined by comparing the ionization with the count-rate observations from the Explorer IV satellite. This result implied that protons are the predominant species which gave rise to the observed ionization.