English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

This is the second paper studying the QSOs in the spitzer QUEST sample.Previously we presented new PAH measurements and argued that most of theobserved far infrared (FIR) radiation is due to star-forming activity. Here wepresent spectral energy distributions (SEDs) by supplementing our data withoptical, NIR and FIR observations. We define two sub-groups of ``weak FIR'' and``strong FIR'' QSOs, and a third group of FIR non-detections. Assuming astarburst origin for the FIR, we obtain ``intrinsic'' AGN SEDs by subtracting astarburst template from the mean SEDs. The resulting SEDs are remarkablysimilar for all groups. They show three distinct peaks corresponding to twosilicate emission features and a 3mic bump that we interpret as the signatureof the hottest AGN dust. They also display drops beyond 20mic that we interpretas the signature of the minimum temperature (about 200K) dust. This componentmust be optically thin to explain the silicate emission and the slope of thelong wavelength continuum. We discuss the merits of an alternative model wheremost of the FIR emission is due to AGN heating. Such models are unlikely toexplain the properties of our QSOs but they cannot be ruled out for moreluminous objects. We also find correlations between the luminosity at 5100A andtwo infrared starburst indicators: L(60mic) and L(PAH 7.7mic). The correlationof L(5100A) with L(60mic) can be used to measure the relative growth rates andlifetimes of the black hole and the new stars.

Spitzer Quasar and ULIRG Evolution Study (QUEST): II. The Spectral Energy Distributions of Palomar-Green Quasars