32 research outputs found
The SPTPoL extended cluster survey
We describe the observations and resultant galaxy cluster catalog from the 2770 deg2 SPTpol Extended Cluster Survey (SPT-ECS). Clusters are identified via the Sunyaev-Zel'dovich (SZ) effect and confirmed with a combination of archival and targeted follow-up data, making particular use of data from the Dark Energy Survey (DES). With incomplete follow-up we have confirmed as clusters 244 of 266 candidates at a detection significance ξ ≥ 5 and an additional 204 systems at 4 4 threshold, and 10% of their measured SZ flux. We associate SZ-selected clusters, from both SPT-ECS and the SPT-SZ survey, with clusters from the DES redMaPPer sample, and we find an offset distribution between the SZ center and central galaxy in general agreement with previous work, though with a larger fraction of clusters with significant offsets. Adopting a fixed Planck-like cosmology, we measure the optical richness-SZ mass (l - M) relation and find it to be 28% shallower than that from a weak-lensing analysis of the DES data-a difference significant at the 4σ level-with the relations intersecting at λ = 60. The SPT-ECS cluster sample will be particularly useful for studying the evolution of massive clusters and, in combination with DES lensing observations and the SPT-SZ cluster sample, will be an important component of future cosmological analyses
Detection of CMB-cluster lensing using polarization data from SPTpol
We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes
Q
U
map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol
500
deg
2
survey at the locations of roughly 18 000 clusters with richness
λ
≥
10
from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at
4.8
σ
. The mean stacked mass of the selected sample is found to be
(
1.43
±
0.40
)
×
10
14
M
⊙
which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements
Joint analysis of Dark Energy Survey Year 3 data and CMB lensing from SPT and Planck . I. Construction of CMB lensing maps and modeling choices
Joint analyses of cross-correlations between measurements of galaxy positions, galaxy lensing, and lensing of the cosmic microwave background (CMB) offer powerful constraints on the large-scale structure of the Universe. In a forthcoming analysis, we will present cosmological constraints from the analysis of such cross-correlations measured using Year 3 data from the Dark Energy Survey (DES), and CMB data from the South Pole Telescope (SPT) and Planck. Here we present two key ingredients of this analysis: (1) an improved CMB lensing map in the SPT-SZ survey footprint and (2) the analysis methodology that will be used to extract cosmological information from the cross-correlation measurements. Relative to previous lensing maps made from the same CMB observations, we have implemented techniques to remove contamination from the thermal Sunyaev Zel’dovich effect, enabling the extraction of cosmological information from smaller angular scales of the cross-correlation measurements than in previous analyses with DES Year 1 data. We describe our model for the cross-correlations between these maps and DES data, and validate our modeling choices to demonstrate the robustness of our analysis. We then forecast the expected cosmological constraints from the galaxy survey-CMB lensing auto and cross-correlations. We find that the galaxy-CMB lensing and galaxy shear-CMB lensing correlations will on their own provide a constraint on
S
8
=
σ
8
√
Ω
m
/
0.3
at the few percent level, providing a powerful consistency check for the DES-only constraints. We explore scenarios where external priors on shear calibration are removed, finding that the joint analysis of CMB lensing cross-correlations can provide constraints on the shear calibration amplitude at the 5% to 10% level
Joint analysis of Dark Energy Survey Year 3 data and CMB lensing from SPT and Planck . II. Cross-correlation measurements and cosmological constraints
Cross-correlations of galaxy positions and galaxy shears with maps of gravitational lensing of the cosmic microwave background (CMB) are sensitive to the distribution of large-scale structure in the Universe. Such cross-correlations are also expected to be immune to some of the systematic effects that complicate correlation measurements internal to galaxy surveys. We present measurements and modeling of the cross-correlations between galaxy positions and galaxy lensing measured in the first three years of data from the Dark Energy Survey with CMB lensing maps derived from a combination of data from the
2500
deg
2
SPT-SZ survey conducted with the South Pole Telescope and full-sky data from the Planck satellite. The CMB lensing maps used in this analysis have been constructed in a way that minimizes biases from the thermal Sunyaev Zel’dovich effect, making them well suited for cross-correlation studies. The total signal-to-noise of the cross-correlation measurements is 23.9 (25.7) when using a choice of angular scales optimized for a linear (nonlinear) galaxy bias model. We use the cross-correlation measurements to obtain constraints on cosmological parameters. For our fiducial galaxy sample, which consist of four bins of magnitude-selected galaxies, we find constraints of
Ω
m
=
0.272
+
0.032
−
0.052
and
S
8
≡
σ
8
√
Ω
m
/
0.3
=
0.736
+
0.032
−
0.028
(
Ω
m
=
0.245
+
0.026
−
0.044
and
S
8
=
0.734
+
0.035
−
0.028
) when assuming linear (nonlinear) galaxy bias in our modeling. Considering only the cross-correlation of galaxy shear with CMB lensing, we find
Ω
m
=
0.270
+
0.043
−
0.061
and
S
8
=
0.740
+
0.034
−
0.029
. Our constraints on
S
8
are consistent with recent cosmic shear measurements, but lower than the values preferred by primary CMB measurements from Planck
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CMB/kSZ and Compton-y Maps from 2500 deg2of SPT-SZ and Planck Survey Data
We present component-separated maps of the primary cosmic microwave background/kinematic Sunyaev-Zel'dovich (SZ) amplitude and the thermal SZ Compton-y parameter, created using data from the South Pole Telescope (SPT) and the Planck satellite. These maps, which cover the a1/42500 deg2 of the southern sky imaged by the SPT-SZ survey, represent a significant improvement over previous such products available in this region by virtue of their higher angular resolution ( 1.′25 for our highest-resolution Compton-y maps) and lower noise at small angular scales. In this work we detail the construction of these maps using linear combination techniques, including our method for limiting the correlation of our lowest-noise Compton-y map products with the cosmic infrared background. We perform a range of validation tests on these data products to test our sky modeling and combination algorithms, and we find good performance in all of these tests. Recognizing the potential utility of these data products for a wide range of astrophysical and cosmological analyses, including studies of the gas properties of galaxies, groups, and clusters, we make these products publicly available at http://pole.uchicago.edu/public/data/sptsz_ymap and on the NASA/LAMBDA website. © 2022. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Combining Planck and SPT cluster catalogs: cosmological analysis and impact on Planck scaling relation calibration
We provide the first combined cosmological analysis of South Pole Telescope (SPT) and Planck cluster catalogs. The aim is to provide an independent calibration for Planck scaling relations, exploiting the cosmological constraining power of the SPT-SZ cluster catalog and its dedicated weak lensing (WL) and X-ray follow-up observations. We build a new version of the Planck cluster likelihood. In the CDM scenario, focusing on the mass slope and mass bias of Planck scaling relations, we find and respectively. The results for the mass slope show a departure from the self-similar evolution, . This shift is mainly driven by the matter density value preferred by SPT data, , lower than the one obtained by Planck data alone, . The mass bias constraints are consistent both with outcomes of hydrodynamical simulations and external WL calibrations, , and with results required by the Planck cosmic microwave background cosmology, . From this analysis, we obtain a new catalog of Planck cluster masses . We estimate the relation between the published Planck derived masses and our derived masses, as a measured mass bias. We analyse the mass, redshift and detection noise dependence of this quantity, finding an increasing trend towards high redshift and low mass. These results mimic the effect of departure from self-similarity in cluster evolution, showing different dependencies for the low-mass high-mass, low-z high-z regimes
Combining Planck and SPT cluster catalogs: cosmological analysis and impact on Planck scaling relation calibration
We provide the first combined cosmological analysis of South Pole Telescope (SPT) and Planck cluster catalogs. The aim is to provide an independent calibration for Planck scaling relations, exploiting the cosmological constraining power of the SPT-SZ cluster catalog and its dedicated weak lensing (WL) and X-ray follow-up observations. We build a new version of the Planck cluster likelihood. In the CDM scenario, focusing on the mass slope and mass bias of Planck scaling relations, we find and respectively. The results for the mass slope show a departure from the self-similar evolution, . This shift is mainly driven by the matter density value preferred by SPT data, , lower than the one obtained by Planck data alone, . The mass bias constraints are consistent both with outcomes of hydrodynamical simulations and external WL calibrations, , and with results required by the Planck cosmic microwave background cosmology, . From this analysis, we obtain a new catalog of Planck cluster masses . We estimate the relation between the published Planck derived masses and our derived masses, as a measured mass bias. We analyse the mass, redshift and detection noise dependence of this quantity, finding an increasing trend towards high redshift and low mass. These results mimic the effect of departure from self-similarity in cluster evolution, showing different dependencies for the low-mass high-mass, low-z high-z regimes
Measurements of the Cross Spectra of the Cosmic Infrared and Microwave Backgrounds from 95 to 1200 GHz
International audienceWe present measurements of the power spectra of cosmic infrared background (CIB) and cosmic microwave background (CMB) fluctuations in six frequency bands. Maps at the lower three frequency bands, 95, 150, and 220 GHz (3330, 2000, 1360 m) are from the South Pole Telescope, while the upper three frequency bands, 600, 857, and 1200 GHz (500, 350, 250 m) are observed with Herschel/SPIRE. From these data, we produce 21 angular power spectra (six auto- and fifteen cross-frequency) spanning the multipole range . Our measurements are the first to cross-correlate measurements near the peak of the CIB spectrum with maps at 95 GHz, complementing and extending the measurements from Planck Collaboration et al. (2014) at 218, 550, and 857 GHz. The observed fluctuations originate largely from clustered, infrared-emitting, dusty star-forming galaxies, the CMB, and to a lesser extent radio galaxies, active galactic nuclei, and the Sunyaev-Zel'dovich effect
A Measurement of the Cosmic Microwave Background Lensing Potential and Power Spectrum from 500 deg of SPTpol Temperature and Polarization Data
International audienceWe present a measurement of the cosmic microwave background (CMB) lensing potential using 500 deg of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles , using a quadratic estimator on a combination of CMB temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of from sets of temperature-only, polarization-only, and minimum-variance estimators. We measure the lensing amplitude by taking the ratio of the measured spectrum to the expected spectrum from the best-fit CDM model to the 2015 TT+lowP+lensing dataset. For the minimum-variance estimator, we find ; restricting to only polarization data, we find . Considering statistical uncertainties alone, this is the most precise polarization-only lensing amplitude constraint to date (10.1 ), and is more precise than our temperature-only constraint. We perform null tests and consistency checks and find no evidence for significant contamination
Constraints on Cosmological Parameters from the 500 deg SPTpol Lensing Power Spectrum
International audienceWe present cosmological constraints based on the cosmic microwave background (CMB) lensing potential power spectrum measurement from the recent 500 deg SPTpol survey, the most precise CMB lensing measurement from the ground to date. We fit a flat CDM model to the reconstructed lensing power spectrum alone and in addition with other data sets: baryon acoustic oscillations (BAO) as well as primary CMB spectra from Planck and SPTpol. The cosmological constraints based on SPTpol and Planck lensing band powers are in good agreement when analysed alone and in combination with Planck full-sky primary CMB data. With weak priors on the baryon density and other parameters, the CMB lensing data alone provide a 4\% constraint on .. Jointly fitting with BAO data, we find , , and , up to away from the central values preferred by Planck lensing + BAO. However, we recover good agreement between SPTpol and Planck when restricting the analysis to similar scales. We also consider single-parameter extensions to the flat CDM model. The SPTpol lensing spectrum constrains the spatial curvature to be and the sum of the neutrino masses to be eV at 95\% C.L. (with Planck primary CMB and BAO data), in good agreement with the Planck lensing results. With the differences in the of the lensing modes and the angular scales covered in the lensing spectra, this analysis represents an important independent check on the full-sky Planck lensing measurement