Using a radio-quiet subsample of the Sloan Digital Sky Survey spectroscopic quasar catalogue , spanning redshifts 0.5–3.5 , we derive the mean millimetre and far-infrared quasar spectral energy distributions ( SEDs ) via a stacking analysis of Atacama Cosmology Telescope and Herschel -Spectral and Photometric Imaging REceiver data .
We constrain the form of the far-infrared emission and find 3 \sigma –4 \sigma evidence for the thermal Sunyaev-Zel ’ dovich ( SZ ) effect , characteristic of a hot ionized gas component with thermal energy ( 6.2 \pm 1.7 ) ~ { } \times~ { } 10 ^ { 60 } erg .
This amount of thermal energy is greater than expected assuming only hot gas in virial equilibrium with the dark matter haloes of ( 1 - 5 ) \times~ { } 10 ^ { 12 } h ^ { -1 } M _ { \odot } that these systems are expected to occupy , though the highest quasar mass estimates found in the literature could explain a large fraction of this energy .
Our measurements are consistent with quasars depositing up to ( 14.5 \pm 3.3 ) ~ { } \tau _ { 8 } ^ { -1 } per cent of their radiative energy into their circumgalactic environment if their typical period of quasar activity is \tau _ { 8 } \times~ { } 10 ^ { 8 } yr. For high quasar host masses , \sim 10 ^ { 13 } h ^ { -1 } M _ { \odot } , this percentage will be reduced .
Furthermore , the uncertainty on this percentage is only statistical and additional systematic uncertainties enter at the 40 per cent level .
The SEDs are dust dominated in all bands and we consider various models for dust emission .
While sufficiently complex dust models can obviate the SZ effect , the SZ interpretation remains favoured at the 3 \sigma –4 \sigma level for most models .