Abstract
We perform a joint fit to differential number counts from Spitzer's MIPS and
Herschel's SPIRE instruments, and angular power spectra of cosmic infrared
background (CIB) anisotropies from SPIRE, Planck, the Atacama Cosmology
Telescope, and the South Pole Telescope, which together span 220 < / GHz <
4300 (70 < / m < 1400). We simultaneously constrain the dust
luminosity function, thermal dust spectral energy distribution (SED) and
clustering properties of CIB sources, and the evolution of these quantities
over cosmic time. We find that the data strongly require redshift evolution in
the thermal dust SED. In our adopted parametrization, this evolution takes the
form of an increase in graybody dust temperature at high redshift, but it may
also be related to a temperature - dust luminosity correlation or evolution in
dust opacity. The counts and spectra together constrain the evolution of the
thermal dust luminosity function up to z ~ 2.5-3, complementing approaches
relying on rest-frame mid-infrared observations of the rarest bright objects.
We are able to fit the power spectra without requiring a complex halo model
approach, and show that neglecting scale-dependent halo bias may be impairing
analyses that do use this framework. Our model has considerable predictive
power and can be used to calculate any one- or two-point statistic of the CIB
over a wide range of frequency and angular scale.
Description
Constraining thermal dust emission in distant galaxies with number
counts and angular power spectra
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