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Constraining models of f(R) gravity with Planck and WiggleZ power spectrum data
Hu, Bin; Dossett, Jason; Parkinson, David
In order to explain cosmic acceleration without invoking ``dark'' physics, we consider f(R) modified gravity models, which replace the standard Einstein-Hilbert action in General Relativity with a higher derivative theory. We use data from the WiggleZ Dark Energy survey to probe the formation of structure on large scales which can place tight cons…
A Far-infrared Spectroscopic Survey of Intermediate Redshift (Ultra) Luminous Infrared Galaxies
Valtchanov, I.; Bock, J. J.; Scott, D. +16 more
We present Herschel far-IR photometry and spectroscopy as well as ground-based CO observations of an intermediate redshift (0.21 <= z <= 0.88) sample of Herschel-selected (ultra)-luminous infrared galaxies (L IR > 1011.5 L ⊙). With these measurements, we trace the dust continuum, far-IR atomic line emissio…
The soft component and the iron line as signatures of the disc inner radius in Galactic black hole binaries
Done, Chris; Kolehmainen, Mari; Díaz Trigo, María
The inner radius of the accretion disc around a black hole in the low/hard state can be measured in one of two ways. First, via the extent of broadening of the iron emission line, and secondly, from the luminosity and temperature of the weak soft component seen in this state, assuming it is the disc. We use both of these methods on all the low/har…
Rapid and multiband variability of the TeV bright active nucleus of the galaxy IC 310
Maraschi, L.; Covino, S.; Antonelli, L. A. +159 more
Context. The radio galaxy IC 310 has recently been identified as a γ-ray emitter based on observations at GeV energies with Fermi-LAT and at very high energies (VHE, E > 100 GeV) with the MAGIC telescopes. Originally classified as a head-tail radio galaxy, the nature of this object is subject of controversy since its nucleus shows blazar-like b…
Probing the z > 6 Universe with the First Hubble Frontier Fields Cluster A2744
Richard, Johan; Kneib, Jean-Paul; Egami, Eiichi +8 more
The Hubble Frontier Fields program combines the capabilities of the Hubble Space Telescope (HST) with the gravitational lensing of massive galaxy clusters to probe the distant universe to an unprecedented depth. Here, we present the results of the first combined HST and Spitzer observations of the cluster A-2744. We combine the full near-infrared …
First observation of rising-tone magnetosonic waves
Santolík, O.; Chen, L.; Cao, J. B. +7 more
Magnetosonic (MS) waves are linearly polarized emissions confined near the magnetic equator with wave normal angle near 90° and frequency below the lower hybrid frequency. Such waves, also termed equatorial noise, were traditionally known to be "temporally continuous" in their time-frequency spectrogram. Here we show for the first time that MS wav…
Gas and dust in the beta Pictoris moving group as seen by the Herschel Space Observatory
Pinte, C.; Duchêne, G.; Dent, W. R. F. +11 more
Context. Debris discs are thought to be formed through the collisional grinding of planetesimals, and then can be considered as the outcome of planet formation. Understanding the properties of gas and dust in debris discs can help us comprehend the architecture of extrasolar planetary systems. Herschel Space Observatory far-infrared (IR) photometr…
X-Ray Observations of XSS J12270-4859 in a New Low State: A Transformation to a Disk-free Rotation-powered Pulsar Binary
Bogdanov, Slavko; Hessels, Jason W. T.; Bassa, Cees +4 more
We present XMM-Newton and Chandra observations of the low-mass X-ray binary XSS J12270-4859, which experienced a dramatic decline in optical/X-ray brightness at the end of 2012, indicative of the disappearance of its accretion disk. In this new state, the system exhibits previously absent orbital-phase-dependent, large-amplitude X-ray modulations …
Vigorous convection in a sunspot granular light bridge
Lagg, Andreas; Solanki, Sami K.; Danilovic, Sanja +1 more
Context. Light bridges are the most prominent manifestation of convection in sunspots. The brightest representatives are granular light bridges composed of features that appear to be similar to granules.
Aims: An in-depth study of the convective motions, temperature stratification, and magnetic field vector in and around light bridge granules…
Two-zero Majorana textures in the light of the Planck results
Meloni, Davide; Meroni, Aurora; Peinado, Eduardo
The recent results of the Planck experiment put a stringent constraint on the sum of the light neutrino masses, Σimi<0.23 eV (95% C.L.). On the other hand, two-zero Majorana mass matrix textures predict strong correlations among the atmospheric angle sin2θ23 and Σ. We use the Planck result to show that, for the …