36 research outputs found
Composição florística e fitofisionomia de remanescentes disjuntos de Cerrado nos Campos Gerais, PR, Brasil - limite austral do bioma
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
Chemical neurotoxins accelerating axonal transport of neurofilaments.
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