Search Publications
First Evidence of Running Cosmic Vacuum: Challenging the Concordance Model
Solà, Joan; Gómez-Valent, Adrià; de Cruz Pérez, Javier
Despite the fact that a rigid {{Λ }}-term is a fundamental building block of the concordance ΛCDM model, we show that a large class of cosmological scenarios with dynamical vacuum energy density {ρ }{{Λ }} together with a dynamical gravitational coupling G or a possible non-conservation of matter, are capable of seriously challenging th…
A New, Large-scale Map of Interstellar Reddening Derived from H I Emission
Hensley, Brandon S.; Doré, Olivier; Lenz, Daniel
We present a new map of interstellar reddening, covering the 39% of the sky with low H I column densities (NHI< 4× 1020 cm-2 or E(B-V)≈ 45 mmag) at 16.1\prime resolution, based on all-sky observations of Galactic H I emission by the HI4PI Survey. In this low-column-density regime, we derive a characteristic valu…
X-Ray Morphological Analysis of the Planck ESZ Clusters
Lovisari, Lorenzo; Andrade-Santos, Felipe; Jones, Christine +7 more
X-ray observations show that galaxy clusters have a very large range of morphologies. The most disturbed systems, which are good to study how clusters form and grow and to test physical models, may potentially complicate cosmological studies because the cluster mass determination becomes more challenging. Thus, we need to understand the cluster pr…
Tracing Interstellar Magnetic Field Using Velocity Gradient Technique: Application to Atomic Hydrogen Data
Yuen, Ka Ho; Lazarian, A.
The advancement of our understanding of MHD turbulence opens ways to develop new techniques to probe magnetic fields. In MHD turbulence, the velocity gradients are expected to be perpendicular to magnetic fields and this fact was used by González-Casanova & Lazarian to introduce a new technique to trace magnetic fields using velocity centroid …
The Fraction of Cool-core Clusters in X-Ray versus SZ Samples Using Chandra Observations
Lovisari, Lorenzo; Andrade-Santos, Felipe; Jones, Christine +21 more
We derive and compare the fractions of cool-core clusters in the Planck Early Sunyaev-Zel’dovich sample of 164 clusters with z≤slant 0.35 and in a flux-limited X-ray sample of 100 clusters with z≤slant 0.30, using Chandra observations. We use four metrics to identify cool-core clusters: (1) the concentration parameter, which is the ratio of the in…
A Measurement of the Cosmic Microwave Background B-mode Polarization Power Spectrum at Subdegree Scales from Two Years of polarbear Data
Ade, P. A. R.; Baccigalupi, C.; Borrill, J. +79 more
We report an improved measurement of the cosmic microwave background B-mode polarization power spectrum with the Polarbear experiment at 150 GHz. By adding new data collected during the second season of observations (2013-2014) to re-analyzed data from the first season (2012-2013), we have reduced twofold the band-power uncertainties. The band pow…
Occurrence of Radio Minihalos in a Mass-limited Sample of Galaxy Clusters
Clarke, Tracy E.; Giacintucci, Simona; Venturi, Tiziana +3 more
We investigate the occurrence of radio minihalos—diffuse radio sources of unknown origin observed in the cores of some galaxy clusters—in a statistical sample of 58 clusters drawn from the Planck Sunyaev-Zel’dovich cluster catalog using a mass cut (M 500 > 6 × 1014 M ⊙). We supplement our statistical sample with…
CMB Polarization B-mode Delensing with SPTpol and Herschel
Bock, J. J.; Chiang, H. C.; Conley, A. +60 more
We present a demonstration of delensing the observed cosmic microwave background (CMB) B-mode polarization anisotropy. This process of reducing the gravitational-lensing-generated B-mode component will become increasingly important for improving searches for the B modes produced by primordial gravitational waves. In this work, we delens B-mode map…
A 2500 deg2 CMB Lensing Map from Combined South Pole Telescope and Planck Data
Bleem, L. E.; Stark, A. A.; George, E. M. +44 more
We present a cosmic microwave background (CMB) lensing map produced from a linear combination of South Pole Telescope (SPT) and Planck temperature data. The 150 GHz temperature data from the 2500 deg2 SPT-SZ survey is combined with the Planck 143 GHz data in harmonic space to obtain a temperature map that has a broader ℓ coverage and le…
A Comparison of Cosmological Parameters Determined from CMB Temperature Power Spectra from the South Pole Telescope and the Planck Satellite
Bleem, L. E.; Stark, A. A.; George, E. M. +42 more
The Planck cosmic microwave background temperature data are best fit with a ΛCDM model that mildly contradicts constraints from other cosmological probes. The South Pole Telescope (SPT) 2540 {\deg }2 SPT-SZ survey offers measurements on sub-degree angular scales (multipoles 650≤slant {\ell }≤slant 2500) with sufficient precision to use …