Parameter Estimation from Improved Measurements of the Cosmic Microwave Background from QUaD

We evaluate the contribution of cosmic microwave background (CMB) polarization spectra to cosmological parameter constraints. We produce cosmological parameters using high-quality CMB polarization data from the ground-based QUaD experiment and demonstrate for the majority of parameters that there is significant improvement on the constraints obtained from satellite CMB polarization data. We split a multi-experiment CMB data set into temperature and polarization subsets and show that the best-fit confidence regions for the ΛCDM six-parameter cosmological model are consistent with each other, and that polarization data reduces the confidence regions on all parameters. We provide the best limits on parameters from QUaD EE/BB polarization data and we find best-fit parameters from the multi-experiment CMB data set using the optimal pivot scale of k_p = 0.013 Mpc^(–1) to be {h^2Ω_c, h^2Ω_b, H_0, A_s, n_s, τ} = {0.113, 0.0224, 70.6, 2.29 × 10^(–9), 0.960, 0.086}

Measurement of the temperature and polarization anisotropies in the cosmic microwave background with QUaD.

This thesis paper describes QUaD, a millimetric polarimeter designed to precisely measure the temperature and polarization anisotropics in the cosmic microwave background (CMB) radiation. QUaD was built and integrated between 2000 and 2004, and commissioned at the south pole in the austral summer of 2004/2005. First light was achieved in February 2005, and QUaD acquired a full austral winter of data during that year. Modifications to the instrument were performed in the austral summer of 2005/2006, and QUaD is currently taking a second season of data. A third season is planned. QUaD is composed of a cryogenically cooled receiver mounted on a Cassegrain telescope using a 2.6 m primary mirror. The detectors are polarization sensitive Neutron Transmutation Doped germanium bolometers which are coupled to the optics via single- moded corrugated feed horns. These detectors are split between two frequency bands, 100 and 150 GHz, and the optics allow angular resolutions of 6.0 and 4.0 arcminutes in these two bands. The performance of the instrument has been characterized using extensive laboratory data, a battery of tests performed during commissioning, and specially designed measurements during the observing season. QUaD uses constant elevation azimuth scans with 15 degree lengths, allowing reconstruction of all 6 CMB power spectra in the range 50 < &pound; < 2000. Customized software and analysis methods are required to transform data time series from the telescope to refined data products. QUaD data have provided the most accurate measurements of the &pound;-mode CMB power spectrum to date, as well as measurements of T-mode power competitive with the best high angular resolution experiments. These measurements provide a wealth of information, and both confirm our model for the early Universe as well as constrain cosmological parameters. Furthermore, QUaD measures the formation of structure after recombination, and can constrain the physics of inflation

HerMES: Current Cosmic Infrared Background Estimates Can Be Explained by Known Galaxies and Their Faint Companions at z < 4

We report contributions to cosmic infrared background (CIB) intensities originating from known galaxies and their faint companions at submillimeter wavelengths. Using the publicly available UltraVISTA catalog and maps at 250, 350, and 500 μm from the Herschel Multi-tiered Extragalactic Survey, we perform a novel measurement that exploits the fact that uncataloged sources may bias stacked flux densities—particularly if the resolution of the image is poor—and intentionally smooth the images before stacking and summing intensities. By smoothing the maps we are capturing the contribution of faint (undetected in K_S ~ 23.4) sources that are physically associated, or correlated, with the detected sources. We find that the cumulative CIB increases with increased smoothing, reaching 9.82 ± 0.78, 5.77 ± 0.43 and 2.32 ± 0.19 nWm^(-2) sr^(-1) at 250, 350, and 500 μm at 300 arscec FWHM. This corresponds to a fraction of the fiducial CIB of 0.94 ± 0.23, 1.07 ± 0.31, and 0.97 ± 0.26 at 250, 350, and 500 μm, where the uncertainties are dominated by those of the absolute CIB. We then propose, with a simple model combining parametric descriptions for stacked flux densities and stellar mass functions, that emission from galaxies with log(M/M⊙) > 8.5 can account for most of the measured total intensities and argue against contributions from extended, diffuse emission. Finally, we discuss prospects for future survey instruments to improve the estimates of the absolute CIB levels, and observe any potentially remaining emission at z > 4

Herschel observations of a z ∼ 2 stellar mass selected galaxy sample drawn from the GOODS NICMOS Survey

We present a study of the far-infrared (IR) properties of a stellar mass selected sample of 1.5 9.5 drawn from the Great Observatories Origins Deep Survey (GOODS) Near Infrared Camera and Multi-Object Spectrometer (NICMOS) Survey (GNS), the deepest H-band Hubble Space Telescope survey of its type prior to the installation of Wide Field Camera 3 (WFC3). We use far-IR and submm data from the Photoconductor Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) instruments on-board Herschel, taken from the PACS Evolutionary Probe (PEP) and Herschel Multi-Tiered Extragalactic Survey (HerMES) key projects, respectively. We find a total of 22 GNS galaxies, with median log (M_*/M_⊙) = 10.8 and z = 2.0, associated with 250 μm sources detected with signal-to-noise ratio (SNR) > 3. We derive mean total IR luminosity log LIR(L_⊙) = 12.36 ± 0.05 and corresponding star formation rate (SFR)_(IR + UV) = (280 ± 40) M_⊙ yr^(−1) for these objects, and find them to have mean dust temperature T_dust ≈ 35 K. We find that the SFR derived from the far-IR photometry combined with ultraviolet (UV)-based estimates of unobscured SFR for these galaxies is on average more than a factor of 2 higher than the SFR derived from extinction-corrected UV emission alone, although we note that the IR-based estimate is subject to substantial Malmquist bias. To mitigate the effect of this bias and extend our study to fainter fluxes, we perform a stacking analysis to measure the mean SFR in bins of stellar mass. We obtain detections at the 2–4σ level at SPIRE wavelengths for samples with log (M_*/M_⊙) > 10. In contrast to the Herschel detected GNS galaxies, we find that estimates of SFR_(IR + UV) for the stacked samples are comparable to those derived from extinction-corrected UV emission, although the uncertainties are large. We find evidence for an increasing fraction of dust obscured star formation with stellar mass, finding SFR_(IR)/SFR_(UV) ∝ M^(0.7±0.2)_*, which is likely a consequence of the mass–metallicity relation

HerMES: The submillimeter spectral energy distributions of Herschel/SPIRE-detected galaxies

We present colours of sources detected with the Herschel/SPIRE instrument in deep extragalactic surveys of the Lockman Hole, Spitzer-FLS, and GOODS-N fields in three photometric bands at 250, 350 and 500 μm. We compare these with expectations from the literature and discuss associated uncertainties and biases in the SPIRE data. We identify a 500 μm flux limited selection of sources from the HerMES point source catalogue that appears free from neighbouring/blended sources in all three SPIRE bands. We compare the colours with redshift tracks of various contemporary models. Based on these spectral templates we show that regions corresponding to specific population types and redshifts can be identified better in colour-flux space. The redshift tracks as well as the colour-flux plots imply a majority of detected objects with redshifts at 1 < z < 3.5, somewhat depending on the group of model SEDs used. We also find that a population of sources with S_(250)/S_(350) < 0.8 at fluxes above 50 mJy as observed by SPIRE are not well represented by contemporary models and could consist of a mix of cold and lensed galaxies

The Herschel-SPIRE instrument and its in-flight performance

The Spectral and Photometric Imaging REceiver (SPIRE), is the Herschel Space Observatory`s submillimetre camera and spectrometer. It contains a three-band imaging photometer operating at 250, 350 and 500 μm, and an imaging Fourier-transform spectrometer (FTS) which covers simultaneously its whole operating range of 194–671 μm (447–1550 GHz). The SPIRE detectors are arrays of feedhorn-coupled bolometers cooled to 0.3 K. The photometer has a field of view of 4´× 8´, observed simultaneously in the three spectral bands. Its main operating mode is scan-mapping, whereby the field of view is scanned across the sky to achieve full spatial sampling and to cover large areas if desired. The spectrometer has an approximately circular field of view with a diameter of 2.6´. The spectral resolution can be adjusted between 1.2 and 25 GHz by changing the stroke length of the FTS scan mirror. Its main operating mode involves a fixed telescope pointing with multiple scans of the FTS mirror to acquire spectral data. For extended source measurements, multiple position offsets are implemented by means of an internal beam steering mirror to achieve the desired spatial sampling and by rastering of the telescope pointing to map areas larger than the field of view. The SPIRE instrument consists of a cold focal plane unit located inside the Herschel cryostat and warm electronics units, located on the spacecraft Service Module, for instrument control and data handling. Science data are transmitted to Earth with no on-board data compression, and processed by automatic pipelines to produce calibrated science products. The in-flight performance of the instrument matches or exceeds predictions based on pre-launch testing and modelling: the photometer sensitivity is comparable to or slightly better than estimated pre-launch, and the spectrometer sensitivity is also better by a factor of 1.5–2