[en] We explore the fundamental limits to which reionization histories can be constrained using only large-scale cosmic microwave background (CMB) anisotropy measurements. The redshift distribution of the fractional ionization x _e(z) affects the angular distribution of CMB polarization. We project constraints on the reionization history of the universe using low-noise full-sky temperature and E-mode measurements of the CMB. We show that the measured TE power spectrum, ${\stackrel{^<!--\; ^\; -->}{C}}_{\mathrm{\ell <!--\; ???\; -->}}^{\mathrm{T}\mathrm{E}}$, has roughly one quarter of the constraining power of ${\stackrel{^<!--\; ^\; -->}{C}}_{\mathrm{\ell <!--\; ???\; -->}}^{\mathrm{E}\mathrm{E}}$ on the reionization optical depth τ, and its addition improves the precision on τ by 20% over using ${\stackrel{^<!--\; ^\; -->}{C}}_{\mathrm{\ell <!--\; ???\; -->}}^{\mathrm{E}\mathrm{E}}$ only. We also use a two-step reionization model with an additional high-redshift step, parameterized by an early ionization fraction $x_e^{min}$, and a late reionization step at z _re. We find that future high signal-to-noise measurements of the multipoles 10 ≤ ℓ < 20 are especially important for breaking the degeneracy between $x_e^{min}$ and z _re. In addition, we show that the uncertainties on these parameters determined from a map with sensitivity 10 μK arcmin are less than 5% larger than the uncertainties in the noiseless case, making this noise level a natural target for future large sky area E-mode measurements.

[en] We examine the internal consistency of the Planck 2015 cosmic microwave background (CMB) temperature anisotropy power spectrum. We show that tension exists between cosmological constant cold dark matter ($\mathrm{\Lambda <!--\; ??\; -->}\mathrm{C}\mathrm{D}\mathrm{M}$) model parameters inferred from multipoles $\mathrm{\ell <!--\; ???\; -->}<<!--\; <\; -->1000$ (roughly those accessible to Wilkinson Microwave Anisotropy Probe), and from $\mathrm{\ell <!--\; ???\; -->}⩾<!--\; ???\; -->1000$, particularly the CDM density, ${\mathrm{\Omega <!--\; ??\; -->}}_c{h}^2$, which is discrepant at $2.5\mathrm{\sigma <!--\; ??\; -->}$ for a Planck -motivated prior on the optical depth, $\mathrm{\tau <!--\; ??\; -->}=0.07\pm <!--\; ??\; -->0.02$. We find some parameter tensions to be larger than previously reported because of inaccuracy in the code used by the Planck Collaboration to generate model spectra. The Planck $\mathrm{\ell <!--\; ???\; -->}⩾<!--\; ???\; -->1000$ constraints are also in tension with low-redshift data sets, including Planck ’s own measurement of the CMB lensing power spectrum ($2.4\mathrm{\sigma <!--\; ??\; -->}$), and the most precise baryon acoustic oscillation scale determination ($2.5\mathrm{\sigma <!--\; ??\; -->}$). The Hubble constant predicted by Planck from $\mathrm{\ell <!--\; ???\; -->}⩾<!--\; ???\; -->1000$, $H_0=64.1\pm <!--\; ??\; -->1.7$ km s${}^{-<!--\; ???\; -->1}$ Mpc⁻¹, disagrees with the most precise local distance ladder measurement of $73.0\pm <!--\; ??\; -->2.4$ km s${}^{-<!--\; ???\; -->1}$ Mpc⁻¹ at the $3.0\mathrm{\sigma <!--\; ??\; -->}$ level, while the Planck value from $\mathrm{\ell <!--\; ???\; -->}<<!--\; <\; -->1000$, $69.7\pm <!--\; ??\; -->1.7$ km s${}^{-<!--\; ???\; -->1}$ Mpc⁻¹, is consistent within $1\mathrm{\sigma <!--\; ??\; -->}$. A discrepancy between the Planck and South Pole Telescope high-multipole CMB spectra disfavors interpreting these tensions as evidence for new physics. We conclude that the parameters from the Planck high-multipole spectrum probably differ from the underlying values due to either an unlikely statistical fluctuation or unaccounted-for systematics persisting in the Planck data.

[en] We present the first set of maps and band-merged catalog from the Herschel Stripe 82 Survey (HerS). Observations at 250, 350, and 500 μm were taken with the Spectral and Photometric Imaging Receiver instrument aboard the Herschel Space Observatory. HerS covers 79 deg² along the SDSS Stripe 82 to an average depth of 13.0, 12.9, and 14.8 mJy beam^–1 (including confusion) at 250, 350, and 500 μm, respectively. HerS was designed to measure correlations with external tracers of the dark matter density field—either point-like (i.e., galaxies selected from radio to X-ray) or extended (i.e., clusters and gravitational lensing)—in order to measure the bias and redshift distribution of intensities of infrared-emitting dusty star-forming galaxies and active galactic nuclei. By locating HerS in Stripe 82, we maximize the overlap with available and upcoming cosmological surveys. The band-merged catalog contains 3.3 × 10⁴ sources detected at a significance of ≳ 3σ (including confusion noise). The maps and catalog are available at http://www.astro.caltech.edu/hers/

[en] We present measurements of the auto- and cross-frequency power spectra of the cosmic infrared background (CIB) at 250, 350, and 500 μm (1200, 860, and 600 GHz) from observations totaling ∼70 deg² made with the SPIRE instrument aboard the Herschel Space Observatory. We measure a fractional anisotropy δI/I = 14% ± 4%, detecting signatures arising from the clustering of dusty star-forming galaxies in both the linear (2-halo) and nonlinear (1-halo) regimes; and that the transition from the 2- to 1-halo terms, below which power originates predominantly from multiple galaxies within dark matter halos, occurs at k_θ ∼ 0.10-0.12 arcmin^–1 (l ∼ 2160-2380), from 250 to 500 μm. New to this paper is clear evidence of a dependence of the Poisson and 1-halo power on the flux-cut level of masked sources—suggesting that some fraction of the more luminous sources occupy more massive halos as satellites, or are possibly close pairs. We measure the cross-correlation power spectra between bands, finding that bands which are farthest apart are the least correlated, as well as hints of a reduction in the correlation between bands when resolved sources are more aggressively masked. In the second part of the paper, we attempt to interpret the measurements in the framework of the halo model. With the aim of fitting simultaneously with one model the power spectra, number counts, and absolute CIB level in all bands, we find that this is achievable by invoking a luminosity-mass relationship, such that the luminosity-to-mass ratio peaks at a particular halo mass scale and declines toward lower and higher mass halos. Our best-fit model finds that the halo mass which is most efficient at hosting star formation in the redshift range of peak star-forming activity, z ∼ 1-3, is log(M_peak/M_☉) ∼ 12.1 ± 0.5, and that the minimum halo mass to host infrared galaxies is log(M_min/M_☉) ∼ 10.1 ± 0.6