The Atacama Cosmology Telescope: a CMB lensing mass map over 2100 square degrees of sky and its cross-correlation with BOSS-CMASS galaxies

ABSTRACT We construct cosmic microwave background lensing mass maps using data from the 2014 and 2015 seasons of observations with the Atacama Cosmology Telescope (ACT). These maps cover 2100 square degrees of sky and overlap with a wide variety of optical surveys. The maps are signal dominated on large scales and have fidelity such that their correlation with the cosmic infrared background is clearly visible by eye. We also create lensing maps with thermal Sunyaev−Zel’dovich contamination removed using a novel cleaning procedure that only slightly degrades the lensing signal-to-noise ratio. The cross-spectrum between the cleaned lensing map and the BOSS CMASS galaxy sample is detected at 10σ significance, with an amplitude of A = 1.02 ± 0.10 relative to the Planck best-fitting Lambda cold dark matter cosmological model with fiducial linear galaxy bias. Our measurement lays the foundation for lensing cross-correlation science with current ACT data and beyond.

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Hemispherical variance anomaly and reionization optical depth

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3049 ◽

2020 ◽

Vol 499 (3) ◽

pp. 3563-3570

Author(s):

Márcio O’Dwyer ◽

Craig J Copi ◽

Johanna M Nagy ◽

C Barth Netterfield ◽

John Ruhl ◽

...

Keyword(s):

Optical Depth ◽

Large Scale ◽

Cold Dark Matter ◽

Signal To Noise Ratio ◽

Cosmological Parameters ◽

Temperature Data ◽

Microwave Background ◽

Parameter Uncertainties ◽

Polarization Data ◽

Best Fitting

ABSTRACT Cosmic microwave background (CMB) full-sky temperature data show a hemispherical asymmetry in power nearly aligned with the Ecliptic, with the Northern hemisphere displaying an anomalously low variance, while the Southern hemisphere appears consistent with expectations from the best-fitting theory, Lambda Cold Dark Matter (ΛCDM). The low signal-to-noise ratio in current polarization data prevents a similar comparison. Polarization realizations constrained by temperature data show that in ΛCDM the lack of variance is not expected to be present in polarization data. Therefore, a natural way of testing whether the temperature result is a fluke is to measure the variance of CMB polarization components. In anticipation of future CMB experiments that will allow for high-precision large-scale polarization measurements, we study how the variance of polarization depends on ΛCDM-parameter uncertainties by forecasting polarization maps with Planck’s Markov chain Monte Carlo chains. We show that polarization variance is sensitive to present uncertainties in cosmological parameters, mainly due to current poor constraints on the reionization optical depth τ, which drives variance at low multipoles. We demonstrate how the improvement in the τ measurement seen between Planck’s two latest data releases results in a tighter constraint on polarization variance expectations. Finally, we consider even smaller uncertainties on τ and how more precise measurements of τ can drive the expectation for polarization variance in a hemisphere close to that of the cosmic-variance-limited distribution.

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Constraining cosmology with the cosmic microwave and infrared backgrounds correlation

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833765 ◽

2019 ◽

Vol 621 ◽

pp. A32 ◽

Cited By ~ 2

Author(s):

A. Maniyar ◽

G. Lagache ◽

M. Béthermin ◽

S. Ilić

Keyword(s):

Large Scale ◽

Cross Correlation ◽

Signal To Noise Ratio ◽

Cosmological Parameters ◽

Power Spectra ◽

Matrix Analysis ◽

Microwave Background ◽

Residual Level ◽

Infrared Background ◽

The Cross

We explore the use of the cosmic infrared background (CIB) as a tracer of the large scale structures for cross-correlating with the cosmic microwave background (CMB) and exploit the integrated Sachs–Wolfe (ISW) effect. We used an improved linear CIB model from our previous work and derived the theoretical CIB×ISW cross-correlation for different Planck HFI frequencies (217, 353, 545 and 857 GHz) and IRAS (3000 GHz). As expected, we predict a positive cross-correlation between the CIB and the CMB whose amplitude decreases rapidly at small scales. We perform a signal-to-noise ratio (S/N) analysis of the predicted cross-correlation. In the ideal case when the cross-correlation is obtained over 70% (40%) of the sky without residual contaminants (e.g. galactic dust) in maps, the S/N ranges from 4.2 to 5.6 (3.2 to 4.3); the highest S/N comes from 857 GHz. A Fisher matrix analysis shows that an ISW signal detected with a S/N this high on the 40% sky can considerably improve the constraints on the cosmological parameters; constraints on the equation of state of the dark energy especially are improved by 80%. We then performed a more realistic analysis considering the effect of residual galactic dust contamination in CIB maps. We calculated the dust power spectra for different frequencies and sky fractions that dominate the CIB power spectra at the lower multipoles we are interested in. Considering a conservative 10% residual level of galactic dust in the CIB power spectra, we observe that the S/N drops drastically, which makes it very challenging to detect the ISW. To determine the capability of current maps to detect the ISW effect through this method, we measured the cross-correlation of the CIB and the CMB Planck maps on the so-called GASS field, which covers an area of ∼11% in the southern hemisphere. We find that with such a small sky fraction and the dust residuals in the CIB maps, we do not detect any ISW signal, and the measured cross-correlation is consistent with zero. To avoid degrading the S/N for the ISW measurement by more than 10% on the 40% sky, we find that the dust needs to be cleaned up to the 0.01% level on the power spectrum.

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Can assembly bias explain the lensing amplitude of the BOSS CMASS sample in a Planck cosmology?

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa634 ◽

2020 ◽

Vol 493 (4) ◽

pp. 5551-5564

Author(s):

Sihan Yuan ◽

Daniel J Eisenstein ◽

Alexie Leauthaud

Keyword(s):

Cold Dark Matter ◽

Cosmological Parameters ◽

Bias Parameter ◽

Projected Clustering ◽

The Galaxy ◽

Satellite Velocity ◽

Galaxy Sample ◽

Best Fitting ◽

Galaxy Assembly ◽

Halo Occupation Distribution

ABSTRACT In this paper, we investigate whether galaxy assembly bias can reconcile the 20–40 ${{\ \rm per\ cent}}$ disagreement between the observed galaxy projected clustering signal and the galaxy–galaxy lensing signal in the Baryon Oscillation Spectroscopic Survey CMASS galaxy sample. We use the suite of abacuscosmos lambda cold dark matter simulations at Planck best-fitting cosmology and two flexible implementations of extended halo occupation distribution (HOD) models that incorporate galaxy assembly bias to build forward models and produce joint fits of the observed galaxy clustering signal and the galaxy–galaxy lensing signal. We find that our models using the standard HODs without any assembly bias generalizations continue to show a 20–40 ${{\ \rm per\ cent}}$ overprediction of the observed galaxy–galaxy lensing signal. We find that our implementations of galaxy assembly bias do not reconcile the two measurements at Planck best-fitting cosmology. In fact, despite incorporating galaxy assembly bias, the satellite distribution parameter, and the satellite velocity bias parameter into our extended HOD model, our fits still strongly suggest a $\sim \! 34{{\ \rm per\ cent}}$ discrepancy between the observed projected clustering and galaxy–galaxy lensing measurements. It remains to be seen whether a combination of other galaxy assembly bias models, alternative cosmological parameters, or baryonic effects can explain the amplitude difference between the two signals.

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The mass and galaxy distribution around SZ-selected clusters

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab2505 ◽

2021 ◽

Author(s):

T Shin ◽

B Jain ◽

S Adhikari ◽

E J Baxter ◽

C Chang ◽

...

Keyword(s):

Cold Dark Matter ◽

Theoretical Models ◽

Weak Lensing ◽

Mass Selection ◽

Atacama Cosmology Telescope ◽

Cluster Mass ◽

Dark Energy Survey ◽

Radial Profiles ◽

The Galaxy ◽

Galaxy Sample

Abstract We present measurements of the radial profiles of the mass and galaxy number density around Sunyaev-Zel’dovich (SZ)-selected clusters using both weak lensing and galaxy counts. The clusters are selected from the Atacama Cosmology Telescope Data Release 5 and the galaxies from the Dark Energy Survey Year 3 dataset. With signal-to-noise of 62 (45) for galaxy (weak lensing) profiles over scales of about 0.2 − 20h−1 Mpc, these are the highest precision measurements for SZ-selected clusters to date. Because SZ selection closely approximates mass selection, these measurements enable several tests of theoretical models of the mass and light distribution around clusters. Our main findings are: 1. The splashback feature is detected at a consistent location in both the mass and galaxy profiles and its location is consistent with predictions of cold dark matter N-body simulations. 2. The full mass profile is also consistent with the simulations. 3. The shapes of the galaxy and lensing profiles are remarkably similar for our sample over the entire range of scales, from well inside the cluster halo to the quasilinear regime. We measure the dependence of the profile shapes on the galaxy sample, redshift and cluster mass. We extend the Diemer & Kravtsov model for the cluster profiles to the linear regime using perturbation theory and show that it provides a good match to the measured profiles. We also compare the measured profiles to predictions of the standard halo model and simulations that include hydrodynamics. Applications of these results to cluster mass estimation, cosmology and astrophysics are discussed.

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Studying high-z galaxies with [C ii] intensity mapping

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2728 ◽

2019 ◽

Vol 490 (2) ◽

pp. 1928-1943 ◽

Cited By ~ 5

Author(s):

B Yue ◽

A Ferrara

Keyword(s):

Power Spectrum ◽

Shot Noise ◽

Signal To Noise Ratio ◽

Contamination Level ◽

Microwave Background ◽

Noise Component ◽

Intensity Mapping ◽

Detection Depth ◽

Infrared Background ◽

Full Power

ABSTRACT We investigate the [C ii] line intensity mapping (IM) signal from galaxies in the Epoch of Reionization (EoR) to assess its detectability, the possibility to constrain the $L_{\rm C\,{\small II}}\!-\!{\rm SFR}$ relation, and to recover the [C ii] luminosity function (LF) from future experiments. By empirically assuming that ${\rm log}\,L_{\rm C\,{\small II}}={\rm log}\,A+\gamma {\rm SFR}\pm \sigma _\mathrm{ L}$, we derive the [C ii] LF from the observed UV LF, and the [C ii] IM power spectrum. We study the shot noise and the full power spectrum separately. Although, in general, the shot-noise component has a much higher signal-to-noise ratio than the clustering one, it cannot be used to put independent constraints on log A and γ. Full power spectrum measurements are crucial to break such degeneracy and reconstruct the [C ii] LF. In our fiducial survey S1 (inspired by CCAT-p/1000 h) at z ∼ 6, the shot-noise (clustering) signal is detectable for two (one) of the five considered $L_{\rm C\,{\small II}}\!-\!{\rm SFR}$ relations. The shot noise is generally dominated by galaxies with $L_{\rm C\,{\small II}}\gtrsim 10^{8}\!-\!10^{9}~ \mathrm{L}_\odot$ (MUV ∼ −20 to −22), already at reach of ALMA pointed observations. However, given the small field of view of such telescope, an IM experiment would provide unique information on the bright end of the LF. The detection depth of an IM experiment crucially depends on the (poorly constrained) $L_{\rm C\,{\small II}}\!-\!{\rm SFR}$ relation in the EoR. If the $L_{\rm C\,{\small II}}\!-\!{\rm SFR}$ relation varies in a wide log A–γ range, but still consistent with ALMA [C ii] LF upper limits, even the signal from galaxies with $L_{\rm C\,{\small II}}$ as faint as ∼107 L⊙ could be detectable. Finally, we consider the contamination by continuum foregrounds (cosmic infrared background, dust, cosmic microwave background) and CO interloping lines, and derive the requirements on the residual contamination level to reliably extract the [C ii] signal.

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Evidence for Gravitational Lensing of the Cosmic Microwave Background Polarization from Cross-Correlation with the Cosmic Infrared Background

Physical Review Letters ◽

10.1103/physrevlett.112.131302 ◽

2014 ◽

Vol 112 (13) ◽

Cited By ~ 72

Author(s):

P. A. R. Ade ◽

Y. Akiba ◽

A. E. Anthony ◽

K. Arnold ◽

M. Atlas ◽

...

Keyword(s):

Cosmic Microwave Background ◽

Gravitational Lensing ◽

Cross Correlation ◽

Microwave Background ◽

Cosmic Microwave Background Polarization ◽

Infrared Background ◽

Cosmic Infrared Background

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Cross-Correlation of Planck CMB Lensing with DESI-Like LRGs

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3927 ◽

2020 ◽

Author(s):

Ellie Kitanidis ◽

Martin White

Keyword(s):

Large Scale ◽

Cross Correlation ◽

Theory Model ◽

Microwave Background ◽

Redshift Distribution ◽

Luminous Red Galaxies ◽

Bias Model ◽

Cross Correlations ◽

Galaxy Bias ◽

Red Galaxies

Abstract Cross-correlations between the lensing of the cosmic microwave background (CMB) and other tracers of large-scale structure provide a unique way to reconstruct the growth of dark matter, break degeneracies between cosmology and galaxy physics, and test theories of modified gravity. We detect a cross-correlation between DESI-like luminous red galaxies (LRGs) selected from DECaLS imaging and CMB lensing maps reconstructed with the Planck satellite at a significance of S/N = 27.2 over scales ℓmin = 30, ℓmax = 1000. To correct for magnification bias, we determine the slope of the LRG cumulative magnitude function at the faint limit as s = 0.999 ± 0.015, and find corresponding corrections on the order of a few percent for $C^{\kappa g}_{\ell }, C^{gg}_{\ell }$ across the scales of interest. We fit the large-scale galaxy bias at the effective redshift of the cross-correlation zeff ≈ 0.68 using two different bias evolution agnostic models: a HaloFit times linear bias model where the bias evolution is folded into the clustering-based estimation of the redshift kernel, and a Lagrangian perturbation theory model of the clustering evaluated at zeff. We also determine the error on the bias from uncertainty in the redshift distribution; within this error, the two methods show excellent agreement with each other and with DESI survey expectations.

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The Atacama Cosmology Telescope: measuring radio galaxy bias through cross-correlation with lensing

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stv991 ◽

2015 ◽

Vol 451 (1) ◽

pp. 849-858 ◽

Cited By ~ 28

Author(s):

R. Allison ◽

S. N. Lindsay ◽

B. D. Sherwin ◽

F. de Bernardis ◽

J. R. Bond ◽

...

Keyword(s):

Cross Correlation ◽

Radio Galaxy ◽

Atacama Cosmology Telescope ◽

Galaxy Bias

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Testing KiDS cross-correlation redshifts with simulations

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038835 ◽

2020 ◽

Vol 642 ◽

pp. A200 ◽

Cited By ~ 1

Author(s):

J. L. van den Busch ◽

H. Hildebrandt ◽

A. H. Wright ◽

C. B. Morrison ◽

C. Blake ◽

...

Keyword(s):

Cross Correlation ◽

Reference Sample ◽

Stage Iv ◽

Attractive Alternative ◽

Wide Field ◽

Redshift Distribution ◽

Galaxy Sample ◽

Cosmic Shear ◽

Galaxy Bias ◽

Reference Samples

Measuring cosmic shear in wide-field imaging surveys requires accurate knowledge of the redshift distribution of all sources. The clustering-redshift technique exploits the angular cross-correlation of a target galaxy sample with unknown redshifts and a reference sample with known redshifts. It represents an attractive alternative to colour-based methods of redshift calibration. Here we test the performance of such clustering redshift measurements using mock catalogues that resemble the Kilo-Degree Survey (KiDS). These mocks are created from the MICE simulation and closely mimic the properties of the KiDS source sample and the overlapping spectroscopic reference samples. We quantify the performance of the clustering redshifts by comparing the cross-correlation results with the true redshift distributions in each of the five KiDS photometric redshift bins. Such a comparison to an informative model is necessary due to the incompleteness of the reference samples at high redshifts. Clustering mean redshifts are unbiased at |Δz|< 0.006 under these conditions. The redshift evolution of the galaxy bias of the reference and target samples represents one of the most important systematic errors when estimating clustering redshifts. It can be reliably mitigated at this level of precision using auto-correlation measurements and self-consistency relations, and will not become a dominant source of systematic error until the arrival of Stage-IV cosmic shear surveys. Using redshift distributions from a direct colour-based estimate instead of the true redshift distributions as a model for comparison with the clustering redshifts increases the biases in the mean to up to |Δz|∼0.04. This indicates that the interpretation of clustering redshifts in real-world applications will require more sophisticated (parameterised) models of the redshift distribution in the future. If such better models are available, the clustering-redshift technique promises to be a highly complementary alternative to other methods of redshift calibration.

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