The Atacama Cosmology Telescope: Temperature and Gravitational Lensing Power Spectrum Measurements from Three Seasons of Data

We present the temperature power spectra of the cosmic microwave background (CMB) derived from the three seasons of data from the Atacama Cosmology Telescope (ACT) at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. We detect and correct for contamination due to the Galactic cirrus in our equatorial maps. We present the results of a number of tests for possible systematic error and conclude that any effects are not significant compared to the statistical errors we quote. Where they overlap, we cross-correlate the ACT and the South Pole Telescope (SPT) maps and show they are consistent. The measurements of higher-order peaks in the CMB power spectrum provide an additional test of the Lambda CDM cosmological model, and help constrain extensions beyond the standard model. The small angular scale power spectrum also provides constraining power on the Sunyaev-Zel'dovich effects and extragalactic foregrounds. We also present a measurement of the CMB gravitational lensing convergence power spectrum at 4.6-sigma detection significance.Comment: 21 pages; 20 figures, Submitted to JCAP, some typos correcte

The Atacama Cosmology Telescope: Sunyaev-Zel'dovich Selected Galaxy Clusters at 148 GHz from Three Seasons of Data

[Abridged] We present a catalog of 68 galaxy clusters, of which 19 are new discoveries, detected via the Sunyaev-Zel'dovich effect (SZ) at 148 GHz in the Atacama Cosmology Telescope (ACT) survey of 504 square degrees on the celestial equator. A subsample of 48 clusters within the 270 square degree region overlapping SDSS Stripe 82 is estimated to be 90% complete for M_500c > 4.5e14 Msun and 0.15 < z < 0.8. While matched filters are used to detect the clusters, the sample is studied further through a "Profile Based Amplitude Analysis" using a single filter at a fixed \theta_500 = 5.9' angular scale. This new approach takes advantage of the "Universal Pressure Profile" (UPP) to fix the relationship between the cluster characteristic size (R_500) and the integrated Compton parameter (Y_500). The UPP scalings are found to be nearly identical to an adiabatic model, while a model incorporating non-thermal pressure better matches dynamical mass measurements and masses from the South Pole Telescope. A high signal to noise ratio subsample of 15 ACT clusters is used to obtain cosmological constraints. We first confirm that constraints from SZ data are limited by uncertainty in the scaling relation parameters rather than sample size or measurement uncertainty. We next add in seven clusters from the ACT Southern survey, including their dynamical mass measurements based on galaxy velocity dispersions. In combination with WMAP7 these data simultaneously constrain the scaling relation and cosmological parameters, yielding \sigma_8 = 0.829 \pm 0.024 and \Omega_m = 0.292 \pm 0.025. The results include marginalization over a 15% bias in dynamical mass relative to the true halo mass. In an extension to LCDM that incorporates non-zero neutrino mass density, we combine our data with WMAP7+BAO+Hubble constant measurements to constrain \Sigma m_\nu < 0.29 eV (95% C. L.).Comment: 32 pages, 21 figures To appear in J. Cosmology and Astroparticle Physic

The Atacama Cosmology Telescope: Data Characterization and Map Making

We present a description of the data reduction and mapmaking pipeline used for the 2008 observing season of the Atacama Cosmology Telescope (ACT). The data presented here at 148 GHz represent 12% of the 90 TB collected by ACT from 2007 to 2010. In 2008 we observed for 136 days, producing a total of 1423 hours of data (11 TB for the 148 GHz band only), with a daily average of 10.5 hours of observation. From these, 1085 hours were devoted to a 850 deg^2 stripe (11.2 hours by 9.1 deg) centered on a declination of -52.7 deg, while 175 hours were devoted to a 280 deg^2 stripe (4.5 hours by 4.8 deg) centered at the celestial equator. We discuss sources of statistical and systematic noise, calibration, telescope pointing, and data selection. Out of 1260 survey hours and 1024 detectors per array, 816 hours and 593 effective detectors remain after data selection for this frequency band, yielding a 38% survey efficiency. The total sensitivity in 2008, determined from the noise level between 5 Hz and 20 Hz in the time-ordered data stream (TOD), is 32 micro-Kelvin sqrt{s} in CMB units. Atmospheric brightness fluctuations constitute the main contaminant in the data and dominate the detector noise covariance at low frequencies in the TOD. The maps were made by solving the least-squares problem using the Preconditioned Conjugate Gradient method, incorporating the details of the detector and noise correlations. Cross-correlation with WMAP sky maps, as well as analysis from simulations, reveal that our maps are unbiased at multipoles ell > 300. This paper accompanies the public release of the 148 GHz southern stripe maps from 2008. The techniques described here will be applied to future maps and data releases.Comment: 20 pages, 18 figures, 6 tables, an ACT Collaboration pape

The Atacama Cosmology Telescope: Two-Season ACTPol Spectra and Parameters

We present the temperature and polarization angular power spectra measured by the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time data collected during 2013-14 using two detector arrays at 149 GHz, from 548 deg$^2$ of sky on the celestial equator. We use these spectra, and the spectra measured with the MBAC camera on ACT from 2008-10, in combination with Planck and WMAP data to estimate cosmological parameters from the temperature, polarization, and temperature-polarization cross-correlations. We find the new ACTPol data to be consistent with the LCDM model. The ACTPol temperature-polarization cross-spectrum now provides stronger constraints on multiple parameters than the ACTPol temperature spectrum, including the baryon density, the acoustic peak angular scale, and the derived Hubble constant. Adding the new data to planck temperature data tightens the limits on damping tail parameters, for example reducing the joint uncertainty on the number of neutrino species and the primordial helium fraction by 20%.Comment: 23 pages, 25 figure

A Measurement of the Millimeter Emission and the Sunyaev-zel'dovich Effect Associated with Low-frequency Radio Sources

We present a statistical analysis of the millimeter-wavelength properties of 1.4 GHz-selected sources and a detection of the Sunyaev-Zel'dovich Effect associated with the halos that host them. The Atacama Cosmology Telescope (ACT) has conducted a survey at 148 GHz, 218 GHz and 277 GHz along the celestial equator. Using samples of radio sources selected at 1.4 GHz from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) Survey and the National Radio Astronomy Observatory Very Large Array Sky Survey (NVSS), we measure the stacked 148, 218 and 277 GHz flux densities for sources with 1.4 GHz flux densities ranging from 5 to 200 mJy. At these flux densities, the radio source population is dominated by active galactic nuclei (AGN), with both steep and at spectrum populations, which have combined radio-to-millimeter spectral indices ranging from 0.5 to 0.95, reecting the prevalence of steep spectrum sources at high flux densities and the presence of at spectrum sources at lower flux densities. The thermal Sunyaev-Zelapos;dovich (SZ) eect associated with the halos that host the AGN is detected at the 5 level through its spectral signature. When we compare the SZ eect with weak lensing measurements of radio galaxies, we find that the relation between the two is consistent with that measured by Planck for local bright galaxies. We present a detection of the SZ eect in some of the lowest mass halos (average M(sub 200) approx. equals 10(exp 13) solar M h(sup-1) (sub 70) ) studied to date. This detection is particularly important in the context of galaxy evolution models, as it confirms that galaxies with radio AGN also typically support hot gaseous halos. With Herschel* observations, we show that the SZ detection is not significantly contaminated by dusty galaxies or by dust associated with the AGN or galaxies hosting the AGN. We show that 5 mJy < S(sub 1:4) < 200 mJy radio sources contribute l(l +1)C(sub l)/(2 pi ) = 0:37+/- 0:03 micro K(exp 2) to the angular power spectrum at l = 3000 at 148 GHz, after accounting for the SZ effect associated with their host halos

The Atacama Cosmology Telescope: Cosmological parameters from three seasons of data

We present constraints on cosmological and astrophysical parameters from high-resolution microwave background maps at 148 GHz and 218 GHz made by the Atacama Cosmology Telescope (ACT) in three seasons of observations from 2008 to 2010. A model of primary cosmological and secondary foreground parameters is fit to the map power spectra and lensing deflection power spectrum, including contributions from both the thermal Sunyaev-Zeldovich (tSZ) effect and the kinematic Sunyaev-Zeldovich (kSZ) effect, Poisson and correlated anisotropy from unresolved infrared sources, radio sources, and the correlation between the tSZ effect and infrared sources. The power ell^2 C_ell/2pi of the thermal SZ power spectrum at 148 GHz is measured to be 3.4 +\- 1.4 muK^2 at ell=3000, while the corresponding amplitude of the kinematic SZ power spectrum has a 95% confidence level upper limit of 8.6 muK^2. Combining ACT power spectra with the WMAP 7-year temperature and polarization power spectra, we find excellent consistency with the LCDM model. We constrain the number of effective relativistic degrees of freedom in the early universe to be Neff=2.79 +\- 0.56, in agreement with the canonical value of Neff=3.046 for three massless neutrinos. We constrain the sum of the neutrino masses to be Sigma m_nu < 0.39 eV at 95% confidence when combining ACT and WMAP 7-year data with BAO and Hubble constant measurements. We constrain the amount of primordial helium to be Yp = 0.225 +\- 0.034, and measure no variation in the fine structure constant alpha since recombination, with alpha/alpha0 = 1.004 +/- 0.005. We also find no evidence for any running of the scalar spectral index, dns/dlnk = -0.004 +\- 0.012.Comment: 26 pages, 22 figures. This paper is a companion to Das et al. (2013) and Dunkley et al. (2013). Matches published JCAP versio

A measurement of the millimetre emission and the Sunyaev-Zel'dovich effect associated with low-frequency radio sources

We present a statistical analysis of the millimetre-wavelength properties of 1.4GHz-selected sources and a detection of the Sunyaev–Zel’dovich (SZ) effect associated with the haloes that host them. We stack data at 148, 218 and 277GHz from the Atacama Cosmology Telescope at the positions of a large sample of radio AGN selected at 1.4GHz. The thermal SZ effect associated with the haloes that host the AGN is detected at the 5σ level through its spectral signature, representing a statistical detection of the SZ effect in some of the lowest mass haloes (average M 200 ≈ 10 13 M. h −1 70 ) studied to date. The relation between the SZ effect and mass (based on weak lensing measurements of radio galaxies) is consistent with that measured by Planck for local bright galaxies. In the context of galaxy evolution models, this study confirms that galaxies with radio AGN also typically support hot gaseous haloes. Adding Herschel observations allows us to show that the SZ signal is not significantly contaminated by dust emission. Finally, we analyse the contribution of radio sources to the angular power spectrum of the cosmic microwave background

The atacama cosmology telescope: lensing of CMB temperature and polarization derived from cosmic infrared background cross-correlation

We present a measurement of the gravitational lensing of the Cosmic Microwave Background (CMB) temperature and polarization fields obtained by cross-correlating the reconstructed convergence signal from the first season of Atacama Cosmology Telescope Polarimeter data at 146 GHz with Cosmic Infrared Background (CIB) fluctuations measured using the Planck satellite. Using an effective overlap area of 92.7 square degrees, we detect gravitational lensing of the CMB polarization by large-scale structure at a statistical significance of $4.5\sigma$. Combining both CMB temperature and polarization data gives a lensing detection at $9.1\sigma$ significance. A B-mode polarization lensing signal is present with a significance of $3.2\sigma$. We also present the first measurement of CMB lensing–CIB correlation at small scales corresponding to $l\gt 2000$. Null tests and systematic checks show that our results are not significantly biased by astrophysical or instrumental systematic effects, including Galactic dust. Fitting our measurements to the best-fit lensing-CIB cross-power spectrum measured in Planck data, scaled by an amplitude A, gives $A={1.02}_{-0.08}^{+0.12}$(stat.) ± 0.06(syst.), consistent with the Planck results

The Atacama Cosmology Telescope: CMB Polarization at 200<ℓ<9000200<\ell<9000

We report on measurements of the cosmic microwave background (CMB) and celestial polarization at 146 GHz made with the Atacama Cosmology Telescope Polarimeter (ACTPol) in its first three months of observing. Four regions of sky covering a total of 270 square degrees were mapped with an angular resolution of $1.3'$. The map noise levels in the four regions are between 11 and 17 $\mu$K-arcmin. We present TT, TE, EE, TB, EB, and BB power spectra from three of these regions. The observed E-mode polarization power spectrum, displaying six acoustic peaks in the range $200<\ell<3000$, is an excellent fit to the prediction of the best-fit cosmological models from WMAP9+ACT and Planck data. The polarization power spectrum, which mainly reflects primordial plasma velocity perturbations, provides an independent determination of cosmological parameters consistent with those based on the temperature power spectrum, which results mostly from primordial density perturbations. We find that without masking any point sources in the EE data at $\ell<9000$, the Poisson tail of the EE power spectrum due to polarized point sources has an amplitude less than $2.4$ $\mu$K$^2$ at $\ell = 3000$ at 95\% confidence. Finally, we report that the Crab Nebula, an important polarization calibration source at microwave frequencies, has 8.7\% polarization with an angle of $150.7^\circ \pm 0.6^\circ$ when smoothed with a $5'$ Gaussian beam.Comment: 16 pages, 15 figures, 5 table

Oxygen isotopes of seawater and oxygen and nitrogen isotopes of dissolved nitrate measured in the Gulf of Maine in October, 2016

This dataset contains salinity and stable isotope measurements taken of water samples collected during an October 2016 research cruise in the Gulf of Maine aboard the NOAA ship Pisces. Water samples were collected at 44 different stations throughout the Gulf of Maine at various depths from the surface to the seafloor using a carousel sampler with 12 different Niskin bottles and attached to a SeaBIRD 911 CTD. Salinity was measured in situ using the SeaBird 911 CTD with auxiliary sensors. Water samples were collected from depth in Niskin bottles and transferred to triple rinsed Thermo Scientific Nalgene 4 Oz natural hdpe plastic wide mouth leakproof bottles. Parafilm was secured around the cap of each bottle to help prevent evaporation. Samples designated for δ18O(water) analyses were stored in containers in the wet lab of the boat. Samples designated for δ15N(NO3-) and δ18O(NO3-) analyses were immediately placed in a walk-in freezer set at − 8°C. Once back at port, samples were overnight shipped to the Stable Isotope Lab at Iowa State University. Frozen samples were shipped in coolers with additional ice added and, upon arrival, immediately placed back in a freezer. This dataset also contains two freshwater samples collected from the Kennebec River in November and December 2016. Samples were hand collected and stored in Thermo Scientific Nalgene 4 Oz natural hdpe plastic wide mouth leakproof bottles. Samples were shipped on dry ice to Iowa State University and processed in the same way as the other saltwater samples as detailed below. Once at Iowa State University, samples designated for δ18O(water) were stored in the temperature controlled laboratory and then analyzed using a Picarro L2130-I Isotopic Liquid Water Analyzer with attached autosampler. Three different isotopic reference standards, VSMOW, USGS 48, and USGS 47, were used. At least one reference standard sample was used per 5 samples. The average combined uncertainty (analytical and average correction factor) was ±0.20‰ (2σ). Samples designated for isotopic analyses (δ15N and δ18O) of dissolved NO3- were first unfrozen at Iowa State University and filtered using 0.2 μm pore filters (Sartorius Minisart high flow syringe sterile PES membrane). Subsequently, water samples were treated with sulfamic acid (ACS grade, 99.3-100.3%) to remove any NO2- following the procedures outlined in Granger and Sigman (2009; doi:10.1002/rcm.4307). Briefly, glassware was acid washed and baked at 500°C. 60 ml of sample were treated with 600 μL 0.4M sulfamic acid (made using 10% v/v HCl) to reduce the pH to between 1.6 and 1.8, which is necessary to reduce NO2- to N2 and therefore remove it from the sample. After the reaction was allowed to occur for at least 5 min, samples were neutralized by adding 2M NaOH to the sample to return the sample to a pH of 7 (±0.5). Approximately 310 μL of NaOH were added to each sample but the exact amount of NaOH varied by sample and was determined using a pH meter. Samples were then refrozen, put on dry ice and shipped overnight to the University of California Davis Stable Isotope Facility. Samples were analyzed for δ15N(NO3-) and δ18O(NO3-) using the bacterial denitrification assay method as outlined by Sigman et al., (2001; doi:10.1021/ac010088e) and Casciotti et al., (2002; doi:10.1021/ac020113w), respectively. Isotopes were measured using a Thermoscientific Delta V Plus isotope ratio mass spectrometer coupled to a ThermoFinnigan GasBench + PreCon trace gas concentration system. Seven different reference standards were used to correct samples and report values on the international scale, Air: USGS34 KNO3, USGS35 NaNO3, Acros KNO3, Fisher KNO3, Strem KNO3, New Acros KNO3, and IAEA-NO-3 KNO3 (not used on all samples). Average analytical uncertainty (2σ) was ±0.5‰ for δ15N(NO3-) and ±0.3‰ for δ18O(NO3-). In order to assess the extent to which nitrification is occurring in the Gulf of Maine, we used the following equation for Δ(15, 18), first proposed by Sigman et al., (2005; doi:10.1029/2005GB002458): Δ(15, 18) = (δ15N(NO3-) - δ15Nm)-(15ε/18ε)x(δ18O(NO3-)-δ18Om) δ15Nm and δ18Om are mean δ15N and δ18O of dissolved NO3- in deep source waters, respectively. In this case, we use average values for samples taken at and below 100 m, where δ15N(NO3-) and δ18O(NO3-) remain relatively constant with depth. 15ε/18ε is the ratio of isotope fractionation factors for nitrogen and oxygen, respectively, for assimilation, which is taken to be 1 here. The propagated ([a2+b2]1/2) uncertainty for Δ(15, 18), calculated using the uncertainty associated with δ15N(NO3-) and δ18O(NO3-), is ±0.6‰ (2σ)