scholarly journals Detecting Gravitational Lensing of the Cosmic Microwave Background by Galaxy Clusters

2014 ◽  
Author(s):  
Eric Jones Baxter
Keyword(s):  
Cosmic Microwave Background ◽  
Galaxy Clusters ◽  
Gravitational Lensing ◽  
Microwave Background

scholarly journals Mass Estimation of Galaxy Clusters with Deep Learning II. Cosmic Microwave Background Cluster Lensing

2021 ◽  
Vol 923 (1) ◽  
pp. 96
Author(s):  
N. Gupta ◽  
C. L. Reichardt
Keyword(s):  
Deep Learning ◽  
Cosmic Microwave Background ◽  
Galaxy Clusters ◽  
Gravitational Lensing ◽  
Galaxy Cluster ◽  
Learning Model ◽  
Potential Bias ◽  
Microwave Background ◽  
The Masses ◽  
Deep Learning Model

Abstract We present a new application of deep learning to reconstruct the cosmic microwave background (CMB) temperature maps from images of the microwave sky and to use these reconstructed maps to estimate the masses of galaxy clusters. We use a feed-forward deep-learning network, mResUNet, for both steps of the analysis. The first deep-learning model, mResUNet-I, is trained to reconstruct foreground and noise-suppressed CMB maps from a set of simulated images of the microwave sky that include signals from the CMB, astrophysical foregrounds like dusty and radio galaxies, instrumental noise as well as the cluster’s own thermal Sunyaev–Zel’dovich signal. The second deep-learning model, mResUNet-II, is trained to estimate cluster masses from the gravitational-lensing signature in the reconstructed foreground and noise-suppressed CMB maps. For SPTpol-like noise levels, the trained mResUNet-II model recovers the mass for 104 galaxy cluster samples with a 1σ uncertainty Δ M 200 c est / M 200 c est = 0.108 and 0.016 for input cluster mass M 200 c true = 10 14 M ⊙ and 8 × 1014 M ⊙, respectively. We also test for potential bias on recovered masses, finding that for a set of 105 clusters the estimator recovers M 200 c est = 2.02 × 10 14 M ⊙ , consistent with the input at 1% level. The 2σ upper limit on potential bias is at 3.5% level.

scholarly journals KiDS+VIKING-450 and DES-Y1 combined: Cosmology with cosmic shear

2020 ◽  
Vol 638 ◽  
pp. L1 ◽  
Author(s):  
S. Joudaki ◽  
H. Hildebrandt ◽  
D. Traykova ◽  
N. E. Chisari ◽  
C. Heymans ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cosmic Microwave Background ◽  
Gravitational Lensing ◽  
Error Model ◽  
Calibration Error ◽  
Microwave Background ◽  
Weak Gravitational Lensing ◽  
Dark Energy Survey ◽  
Cosmic Shear ◽  
Energy Survey

We present a combined tomographic weak gravitational lensing analysis of the Kilo Degree Survey (KV450) and the Dark Energy Survey (DES-Y1). We homogenize the analysis of these two public cosmic shear datasets by adopting consistent priors and modeling of nonlinear scales, and determine new redshift distributions for DES-Y1 based on deep public spectroscopic surveys. Adopting these revised redshifts results in a 0.8σ reduction in the DES-inferred value for S​8, which decreases to a 0.5σ reduction when including a systematic redshift calibration error model from mock DES data based on the MICE2 simulation. The combined KV450+DES-Y1 constraint on S8 = 0.762−0.024+0.025 is in tension with the Planck 2018 constraint from the cosmic microwave background at the level of 2.5σ. This result highlights the importance of developing methods to provide accurate redshift calibration for current and future weak-lensing surveys.

scholarly journals Full-sky maps for gravitational lensing of the cosmic microwave background

2008 ◽  
Vol 388 (4) ◽  
pp. 1618-1626 ◽  
Author(s):  
Carmelita Carbone ◽  
Volker Springel ◽  
Carlo Baccigalupi ◽  
Matthias Bartelmann ◽  
Sabino Matarrese
Keyword(s):  
Cosmic Microwave Background ◽  
Gravitational Lensing ◽  
Microwave Background

scholarly journals AMIBA: FIRST-YEAR RESULTS FOR SUNYAEV-ZEL'DOVICH EFFECT

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1675-1686 ◽  
Author(s):  
JIUN-HUEI PROTY WU ◽  
TZI-HONG CHIUEH ◽  
CHI-WEI HUANG ◽  
YAO-WEI LIAO ◽  
FU-CHENG WANG ◽  
...  
Keyword(s):  
Cosmic Microwave Background ◽  
Galaxy Clusters ◽  
First Year ◽  
Microwave Background ◽  
Expansion Plan ◽  
Sunyaev Zel'dovich Effect ◽  
Systematic Effects ◽  
Science Operation

We discuss the observation, analysis, and results of the first-year science operation of AMiBA, an interferometric experiment designed to study cosmology via the measurement of Cosmic Microwave Background (CMB). In 2007, we successfully observed 6 galaxy clusters (z < 0.33) through the Sunyaev-Zel'dovich effect. AMiBA is the first CMB interferometer operating at 86–102 GHz, currently with 7 close-packed antennas of 60 cm in diameter giving a synthesized resolution of around 6 arcminutes. An observing strategy with on-off-source modulation is used to remove the effects from electronic offset and ground pickup. Formalism of the analysis is given and preliminary science results are summarized. Tests for systematic effects are also addressed. We also discuss the expansion plan.

Gravitational Lensing of the Microwave Background by Galaxy Clusters

2004 ◽  
Vol 616 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Gilbert Holder ◽  
Arthur Kosowsky
Keyword(s):  
Galaxy Clusters ◽  
Gravitational Lensing ◽  
Microwave Background
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