30 research outputs found
Measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel'dovich effect with SPT-3G and des
We infer the mean optical depth of a sample of optically selected galaxy clusters from the Dark Energy Survey via the pairwise kinematic Sunyaev-Zel'dovich (KSZ) effect. The pairwise KSZ signal between pairs of clusters drawn from the Dark Energy Survey Year-3 cluster catalog is detected at 4.1 σ in cosmic microwave background temperature maps from two years of observations with the SPT-3G camera on the South Pole Telescope. After cuts, there are 24,580 clusters in the ∼1 ,400 deg2 of the southern sky observed by both experiments. We infer the mean optical depth of the cluster sample with two techniques. The optical depth inferred from the pairwise KSZ signal is τ¯e=(2.97 ±0.73 )×10-3 , while that inferred from the thermal SZ signal is τ¯e=(2.51 ±0.5 5stat±0.1 5syst)×10-3 . The two measures agree at 0.6 σ . We perform a suite of systematic checks to test the robustness of the analysisThe DES participants from Spanish institutions are partially E. SCHIAPPUCCI et al. PHYS. REV. D 107, 042004 (2023) 042004-14 supported by MICINN under Grants No. ESP2017-89838, No. PGC2018-094773, No. PGC2018-102021, No. SEV2016-0588, No. SEV-2016-0597, and No. MDM-2015- 0509, some of which include ERDF funds from the European Union. I. F. A. E. is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013) including ERC Grant Agreements No. 240672, No. 291329, and No. 30647
A Measurement of the CMB Temperature Power Spectrum and Constraints on Cosmology from the SPT-3G 2018 TT/TE/EE Data Set
We present a sample-variance-limited measurement of the temperature power
spectrum () of the cosmic microwave background (CMB) using observations of
a field made by SPT-3G in 2018. We report
multifrequency power spectrum measurements at 95, 150, and 220GHz covering the
angular multipole range . We combine this
measurement with the published polarization power spectrum measurements from
the 2018 observing season and update their associated covariance matrix to
complete the SPT-3G 2018 data set. This is the first analysis to
present cosmological constraints from SPT , , and power spectrum
measurements jointly. We blind the cosmological results and subject the data
set to a series of consistency tests at the power spectrum and parameter level.
We find excellent agreement between frequencies and spectrum types and our
results are robust to the modeling of astrophysical foregrounds. We report
results for CDM and a series of extensions, drawing on the following
parameters: the amplitude of the gravitational lensing effect on primary power
spectra , the effective number of neutrino species
, the primordial helium abundance , and the
baryon clumping factor due to primordial magnetic fields . We find that the
SPT-3G 2018 data are well fit by CDM with a
probability-to-exceed of . For CDM, we constrain the expansion
rate today to and the
combined structure growth parameter to . The SPT-based
results are effectively independent of Planck, and the cosmological parameter
constraints from either data set are within of each other.
(abridged)Comment: 35 Pages, 17 Figures, 11 Table
The Design and Integrated Performance of SPT-3G
SPT-3G is the third survey receiver operating on the South Pole Telescope
dedicated to high-resolution observations of the cosmic microwave background
(CMB). Sensitive measurements of the temperature and polarization anisotropies
of the CMB provide a powerful dataset for constraining cosmology. Additionally,
CMB surveys with arcminute-scale resolution are capable of detecting galaxy
clusters, millimeter-wave bright galaxies, and a variety of transient
phenomena. The SPT-3G instrument provides a significant improvement in mapping
speed over its predecessors, SPT-SZ and SPTpol. The broadband optics design of
the instrument achieves a 430 mm diameter image plane across observing bands of
95 GHz, 150 GHz, and 220 GHz, with 1.2 arcmin FWHM beam response at 150 GHz. In
the receiver, this image plane is populated with 2690 dual-polarization,
tri-chroic pixels (~16000 detectors) read out using a 68X digital
frequency-domain multiplexing readout system. In 2018, SPT-3G began a multiyear
survey of 1500 deg of the southern sky. We summarize the unique optical,
cryogenic, detector, and readout technologies employed in SPT-3G, and we report
on the integrated performance of the instrument.Comment: 25 pages, 11 figures. Submitted to ApJ
A Measurement of Gravitational Lensing of the Cosmic Microwave Background Using SPT-3G 2018 Data
We present a measurement of gravitational lensing over 1500 deg of the
Southern sky using SPT-3G temperature data at 95 and 150 GHz taken in 2018. The
lensing amplitude relative to a fiducial Planck 2018 CDM cosmology is
found to be , excluding instrumental and astrophysical
systematic uncertainties. We conduct extensive systematic and null tests to
check the robustness of the lensing measurements, and report a minimum-variance
combined lensing power spectrum over angular multipoles of , which
we use to constrain cosmological models. When analyzed alone and jointly with
primary cosmic microwave background (CMB) spectra within the CDM
model, our lensing amplitude measurements are consistent with measurements from
SPT-SZ, SPTpol, ACT, and Planck. Incorporating loose priors on the baryon
density and other parameters including uncertainties on a foreground bias
template, we obtain a constraint on using the SPT-3G 2018 lensing data alone, where
is a common measure of the amplitude of structure today and
is the matter density parameter. Combining SPT-3G 2018 lensing
measurements with baryon acoustic oscillation (BAO) data, we derive parameter
constraints of , , and Hubble constant
km s Mpc. Using CMB anisotropy and lensing measurements from
SPT-3G only, we provide independent constraints on the spatial curvature of
(95% C.L.) and the dark energy density
of (68% C.L.). When combining SPT-3G
lensing data with SPT-3G CMB anisotropy and BAO data, we find an upper limit on
the sum of the neutrino masses of eV (95% C.L.)
Constraints on CDM Extensions from the SPT-3G 2018 and Power Spectra
We present constraints on extensions to the CDM cosmological model
from measurements of the -mode polarization auto-power spectrum and the
temperature--mode cross-power spectrum of the cosmic microwave background
(CMB) made using 2018 SPT-3G data. The extensions considered vary the
primordial helium abundance, the effective number of relativistic degrees of
freedom, the sum of neutrino masses, the relativistic energy density and mass
of a sterile neutrino, and the mean spatial curvature. We do not find clear
evidence for any of these extensions, from either the SPT-3G 2018 dataset alone
or in combination with baryon acoustic oscillation and \textit{Planck} data.
None of these model extensions significantly relax the tension between
Hubble-constant, , constraints from the CMB and from distance-ladder
measurements using Cepheids and supernovae. The addition of the SPT-3G 2018
data to \textit{Planck} reduces the square-root of the determinants of the
parameter covariance matrices by factors of across these models,
signaling a substantial reduction in the allowed parameter volume. We also
explore CMB-based constraints on from combined SPT, \textit{Planck}, and
ACT DR4 datasets. While individual experiments see some indications of
different values between the , , and spectra, the combined
constraints are consistent between the three spectra. For the full
combined datasets, we report , which is the tightest constraint on
from CMB power spectra to date and in tension with the most
precise distance-ladder-based measurement of . The SPT-3G survey is
planned to continue through at least 2023, with existing maps of combined 2019
and 2020 data already having lower noise than the maps used in
this analysis.Comment: Submitted to PRD; 19 pages, 7 figure
Performance and characterization of the SPT-3G digital frequency-domain multiplexed readout system using an improved noise and crosstalk model
The third generation South Pole Telescope camera (SPT-3G) improves upon its predecessor (SPTpol) by an order of magnitude increase in detectors on the focal plane. The technology used to read out and control these detectors, digital frequency-domain multiplexing (DfMUX), is conceptually the same as used for SPTpol, but extended to accommodate more detectors. A nearly 5x expansion in the readout operating bandwidth has enabled the use of this large focal plane, and SPT-3G performance meets the forecasting targets relevant to its science objectives. However, the electrical dynamics of the higher-bandwidth readout differ from predictions based on models of the SPTpol system. To address this, we present an updated derivation for electrical crosstalk in higher-bandwidth DfMUX systems, and identify two previously uncharacterized contributions to readout noise. The updated crosstalk and noise models successfully describe the measured crosstalk and readout noise performance of SPT-3G, and suggest improvements to the readout system for future experiments using DfMUX, such as the LiteBIRD space telescope
Measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel'dovich effect with SPT-3G and des
We infer the mean optical depth of a sample of optically selected galaxy clusters from the Dark Energy Survey via the pairwise kinematic Sunyaev-Zel'dovich (KSZ) effect. The pairwise KSZ signal between pairs of clusters drawn from the Dark Energy Survey Year-3 cluster catalog is detected at 4.1σ in cosmic microwave background temperature maps from two years of observations with the SPT-3G camera on the South Pole Telescope. After cuts, there are 24,580 clusters in the ∼1,400 deg2 of the southern sky observed by both experiments. We infer the mean optical depth of the cluster sample with two techniques. The optical depth inferred from the pairwise KSZ signal is τ¯e=(2.97±0.73)×10-3, while that inferred from the thermal SZ signal is τ¯e=(2.51±0.55stat±0.15syst)×10-3. The two measures agree at 0.6σ. We perform a suite of systematic checks to test the robustness of the analysis
A measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel'dovich effect with SPT-3G and DES
We infer the mean optical depth of a sample of optically-selected galaxy
clusters from the Dark Energy Survey (DES) via the pairwise kinematic
Sunyaev-Zel'dovich (kSZ) effect. The pairwise kSZ signal between pairs of
clusters drawn from the DES Year-3 cluster catalog is detected at
in cosmic microwave background (CMB) temperature maps from two years of
observations with the SPT-3G camera on the South Pole Telescope. After cuts,
there are 24,580 clusters in the deg of the southern sky
observed by both experiments. We infer the mean optical depth of the cluster
sample with two techniques. The optical depth inferred from the pairwise kSZ
signal is , while that inferred
from the thermal SZ signal is . The two measures agree at . We
perform a suite of systematic checks to test the robustness of the analysis