8 research outputs found
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Mass Calibration of Optically Selected des Clusters Using a Measurement of CMB-cluster Lensing with SPTpol Data
We use cosmic microwave background (CMB) temperature maps from the 500 deg 2 SPTpol survey to measure the stacked lensing convergence of galaxy clusters from the Dark Energy Survey (DES) Year-3 redMaPPer (RM) cluster catalog. The lensing signal is extracted through a modified quadratic estimator designed to be unbiased by the thermal Sunyaev-Zel'dovich (tSZ) effect. The modified estimator uses a tSZ-free map, constructed from the SPTpol 95 and 150 GHz data sets, to estimate the background CMB gradient. For lensing reconstruction, we employ two versions of the RM catalog: a flux-limited sample containing 4003 clusters and a volume-limited sample with 1741 clusters. We detect lensing at a significance of 8.7σ(6.7σ) with the flux (volume)-limited sample. By modeling the reconstructed convergence using the Navarro-Frenk-White profile, we find the average lensing masses to be M 200m = (1.62 -0.25+0.32 [stat] ± 0.04 [sys.]) and (1.28 -0.18+0.14 [stat] ± 0.03[sys.])× 10 14 M ⊙ for the volume- and flux-limited samples, respectively. The systematic error budget is much smaller than the statistical uncertainty and is dominated by the uncertainties in the RM cluster centroids. We use the volume-limited sample to calibrate the normalization of the mass-richness scaling relation, and find a result consistent with the galaxy weak-lensing measurements from DES
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Mass calibration of optically selected DES clusters using a measurement of CMB-cluster lensing with SPTpol data
We use cosmic microwave background (CMB) temperature maps from the 500 deg2 SPTpol survey to measure the stacked lensing convergence of galaxy clusters from the Dark Energy Survey (DES) Year-3 redMaPPer (RM) cluster catalog. The lensing signal is extracted through a modified quadratic estimator designed to be unbiased by the thermal Sunyaev-Zel{'}dovich (tSZ) effect. The modified estimator uses a tSZ-free map, constructed from the SPTpol 95 and 150 GHz datasets, to estimate the background CMB gradient. For lensing reconstruction, we employ two versions of the RM catalog: a flux-limited sample containing 4003 clusters and a volume-limited sample with 1741 clusters. We detect lensing at a significance of 8.7 σ (6.7σ) with the flux(volume)-limited sample. By modeling the reconstructed convergence using the Navarro-Frenk-White profile, we find the average lensing masses to be M200m = (1.62 +0.32 −0.25 [stat.] ± 0.04 [sys.]) and (1.28 +0.14 −0.18 [stat.] ±0.03 [sys.])×1014 M⊙for the volume- and flux-limited samples respectively. The systematic error budget is much smaller than the statistical uncertainty and is dominated by the uncertainties in the RM cluster centroids. We use the volume-limited sample to calibrate the normalization of the mass-richness scaling relation, and find a result consistent with the galaxy weak-lensing measurements from DES (Mcclintock et al. 2018)
Features BEYOND TEXAS CITY: THE STATE OF PROCESS SAFETY IN THE UNIONIZED U.S. OIL REFINING INDUSTRY*
ABSTRACT The March 2005 British Petroleum (BP) Texas City Refinery disaster provided a stimulus to examine the state of process safety in the U.S. refining industry. Participatory action researchers conducted a nation-wide mail-back survey of United Steelworkers local unions and collected data from 51 unionized refineries. The study examined the prevalence of highly hazardous conditions key to the Texas City disaster, refinery actions to address those conditions, emergency preparedness and response, process safety systems, and worker training. Findings indicate that the key highly hazardous conditions were pervasive and often resulted in incidents or near-misses. Respondents reported worker training was insufficient and less than a third characterized their refineries as very prepared to respond safely to a hazardous materials emergency. The authors conclude that the potential for future disasters plagues the refining industry. In response, they call for effective proactive OSHA regulation and outline ten urgent and critical actions to improve refinery process safety
SPT Clusters with DES and HST Weak Lensing. II. Cosmological Constraints from the Abundance of Massive Halos
International audienceWe present cosmological constraints from the abundance of galaxy clusters selected via the thermal Sunyaev-Zel'dovich (SZ) effect in South Pole Telescope (SPT) data with a simultaneous mass calibration using weak gravitational lensing data from the Dark Energy Survey (DES) and the Hubble Space Telescope (HST). The cluster sample is constructed from the combined SPT-SZ, SPTpol ECS, and SPTpol 500d surveys, and comprises 1,005 confirmed clusters in the redshift range over a total sky area of 5,200 deg. We use DES Year 3 weak-lensing data for 688 clusters with redshifts and HST weak-lensing data for 39 clusters with . The weak-lensing measurements enable robust mass measurements of sample clusters and allow us to empirically constrain the SZ observable--mass relation. For a flat CDM cosmology, and marginalizing over the sum of massive neutrinos, we measure , , and the parameter combination . Our measurement of and the constraint from Planck CMB anisotropies (2018 TT,TE,EE+lowE) differ by . In combination with that Planck dataset, we place a 95% upper limit on the sum of neutrino masses eV. When additionally allowing the dark energy equation of state parameter to vary, we obtain from our cluster-based analysis. In combination with Planck data, we measure , or a difference with a cosmological constant. We use the cluster abundance to measure in five redshift bins between 0.25 and 1.8, and we find the results to be consistent with structure growth as predicted by the CDM model fit to Planck primary CMB data
SPT Clusters with DES and HST Weak Lensing. II. Cosmological Constraints from the Abundance of Massive Halos
International audienceWe present cosmological constraints from the abundance of galaxy clusters selected via the thermal Sunyaev-Zel'dovich (SZ) effect in South Pole Telescope (SPT) data with a simultaneous mass calibration using weak gravitational lensing data from the Dark Energy Survey (DES) and the Hubble Space Telescope (HST). The cluster sample is constructed from the combined SPT-SZ, SPTpol ECS, and SPTpol 500d surveys, and comprises 1,005 confirmed clusters in the redshift range over a total sky area of 5,200 deg. We use DES Year 3 weak-lensing data for 688 clusters with redshifts and HST weak-lensing data for 39 clusters with . The weak-lensing measurements enable robust mass measurements of sample clusters and allow us to empirically constrain the SZ observable--mass relation. For a flat CDM cosmology, and marginalizing over the sum of massive neutrinos, we measure , , and the parameter combination . Our measurement of and the constraint from Planck CMB anisotropies (2018 TT,TE,EE+lowE) differ by . In combination with that Planck dataset, we place a 95% upper limit on the sum of neutrino masses eV. When additionally allowing the dark energy equation of state parameter to vary, we obtain from our cluster-based analysis. In combination with Planck data, we measure , or a difference with a cosmological constant. We use the cluster abundance to measure in five redshift bins between 0.25 and 1.8, and we find the results to be consistent with structure growth as predicted by the CDM model fit to Planck primary CMB data
SPT Clusters with DES and HST Weak Lensing. II. Cosmological Constraints from the Abundance of Massive Halos
International audienceWe present cosmological constraints from the abundance of galaxy clusters selected via the thermal Sunyaev-Zel'dovich (SZ) effect in South Pole Telescope (SPT) data with a simultaneous mass calibration using weak gravitational lensing data from the Dark Energy Survey (DES) and the Hubble Space Telescope (HST). The cluster sample is constructed from the combined SPT-SZ, SPTpol ECS, and SPTpol 500d surveys, and comprises 1,005 confirmed clusters in the redshift range over a total sky area of 5,200 deg. We use DES Year 3 weak-lensing data for 688 clusters with redshifts and HST weak-lensing data for 39 clusters with . The weak-lensing measurements enable robust mass measurements of sample clusters and allow us to empirically constrain the SZ observable--mass relation. For a flat CDM cosmology, and marginalizing over the sum of massive neutrinos, we measure , , and the parameter combination . Our measurement of and the constraint from Planck CMB anisotropies (2018 TT,TE,EE+lowE) differ by . In combination with that Planck dataset, we place a 95% upper limit on the sum of neutrino masses eV. When additionally allowing the dark energy equation of state parameter to vary, we obtain from our cluster-based analysis. In combination with Planck data, we measure , or a difference with a cosmological constant. We use the cluster abundance to measure in five redshift bins between 0.25 and 1.8, and we find the results to be consistent with structure growth as predicted by the CDM model fit to Planck primary CMB data