The Bolometric Quasar Luminosity Function at z = 0-7
  In this paper, we provide updated constraints on the bolometric quasar
luminosity function (QLF) from $z=0$ to $z=7$. The constraints are based on an
observational compilation that includes observations in the rest-frame IR, B
band, UV, soft and hard X-ray in past decades. Our method follows Hopkins et
al. 2007 with an updated quasar SED model and bolometric and extinction
corrections. The new best-fit bolometric quasar luminosity function behaves
qualitatively different from the Hopkins et al. 2007 model at high redshift.
Compared with the old model, the number density normalization decreases towards
higher redshift and the bright-end slope is steeper at $z\gtrsim 2$. Due to the
paucity of measurements at the faint end, the faint end slope at $z\gtrsim 5$
is quite uncertain. We present two models, one featuring a progressively
steeper faint-end slope at higher redshift and the other featuring a shallow
faint-end slope at $z\gtrsim 5$. Further multi-band observations of the
faint-end QLF are needed to distinguish between these models. The evolutionary
pattern of the bolometric QLF can be interpreted as an early phase likely
dominated by the hierarchical assembly of structures and a late phase likely
dominated by the quenching of galaxies. We explore the implications of this
model on the ionizing photon production by quasars, the CXB spectrum, the SMBH
mass density and mass functions. The predicted hydrogen photoionization rate
contributed by quasars is subdominant during the epoch of reionization and only
becomes important at $z\lesssim 3$. The predicted CXB spectrum, cosmic SMBH
mass density and SMBH mass function are generally consistent with existing
observations.
