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Constraining dynamical dark energy with a divergence-free parametrization in the presence of spatial curvature and massive neutrinos
Constraining dynamical dark energy divergence-free parametrization presence spatial curvature massive neutrinos
2012/2/21
In this paper, we report the results of constraining the dynamical dark energy with a divergence-free parameterization, $w(z) = w_{0} + w_{a}(\frac{\ln(2+z)}{1+z}-\ln2)$, in the presence of spatial cu...
Central free-free-dominated 880 $\micron$ emission in II Zw 40
dust, extinction—galaxies: dwarf—galaxies: evolution—galaxies: individual(II Zw 40)— H II regions— submillimetre: galaxies
2011/10/20
The central star-forming region in a blue compact dwarf galaxy, II Zw 40, was observed in the 340 GHz ($880 \micron$) band at $\sim 5$ arcsec (250 pc) resolution with the Submillimetre Array (SMA). A ...
On Shear-Free perturbations of FLRW Universes
On Shear-Free perturbations of FLRW Universes
2011/10/14
A surprising exact result for the Einstein Field Equations is that if pressure-free matter is moving in a shear-free way, then it must be either expansion-free or rotation-free. It has been suggested ...
Pulsar state switching, timing noise and free precession
dense matter – stars: neutron – stars: oscillations – stars: pulsars –stars: rotation
2011/10/10
Recent radio pulsar observations have shown that a number of pulsars display interesting long term periodicities in their spin-down rates. At least some of these pulsars also undergo sharp changes in ...
Magnetic Energy Storage and Current Density Distributions for Different Force-Free Models
Magnetic fi elds Corona - Active Regions Structure - Electric Cur- rents Current Sheets
2011/10/10
The change in the magnetic configuration due to the increase/decrease of electric current for different force-free models (potential, linear and nonlinear force-free fields) has never been studied in ...
Nonlinear force-free and potential field models of active-region and global coronal fields during the Whole Heliospheric Interval
Nonlinear force-free potential field models
2011/1/13
Between 2008/3/24 and 2008/4/2, the three active regions NOAA active regions 10987, 10988 and 10989 were observed daily by the Synoptic Optical Long-term Investigations of the Sun (SOLIS) Vector Spec...
A comparison of preprocessing methods for solar force-free magnetic field extrapolation
preprocessing methods solar force-free magnetic field extrapolation
2011/1/13
Extrapolations of solar photospheric vector magnetograms into three-dimensional magnetic fields in the chromosphere and corona are usually done under the assumption that the fields are force-free. The...
Particle reacceleration by compressible turbulence in galaxy clusters: effects of reduced mean free path
acceleration of particles - turbulence - radiation mechanisms non{thermal - galaxies clusters general radio continuum general - X{rays general
2010/11/11
Direct evidence for in situ particle acceleration mechanisms in the inter-galactic-medium (IGM) is provided by the di use Mpc{scale synchrotron emissions observed from galaxy clusters.
A High-Order WENO-based Staggered Godunov-type Scheme with Constrained Transport for Force-free Electrodynamics
High Energy Astrophysical Phenomena (astro-ph.HE)
2011/1/7
The force-free (or low inertia) limit of magnetohydrodynamics (MHD) can be applied to many astrophysical objects, including black holes, neutron stars, and accretion disks, where the electromagnetic f...
Free-floating planets: a viable option for panspermia
Earth and Planetary Astrophysics (astro-ph.EP)
2011/1/4
Genomic complexity can be used as a clock with which the moment in which life originated can be measured.
Lyman `bump' galaxies - II. A possible signature of massive extremely metal-poor or metal-free stars in z=3.1 Ly-alpha emitters
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/29
Deep NB359 imaging with Subaru by Iwata et al. have detected surprisingly strong Lyman continuum (LyC; ~900A in the rest-frame) from some LAEs at z=3.1. However, the redshifts might be misidentified d...
Evolution and nucleosynthesis of extremely metal-poor and metal-free low- and intermediate-mass stars II. s-process nucleosynthesis during the core He flash
Solar and Stellar Astrophysics (astro-ph.SR)
2010/12/28
Models of primordial and hyper-metal-poor stars with masses similar to the Sun experience an ingestion of protons into the hot core during the core helium flash phase at the end of their red giant bra...
NASA will begin transmitting commands to its Mars exploration rover Spirit on Monday as part of an escape plan to free the venerable robot from its Martian sand trap. Spirit has been lodged at a site ...
A model for the galactic free-electron distribution。
We investigate the causal temperature profiles in a recent model of a radiating star undergoing dissipative gravitational collapse without the formation of a horizon. It is shown that this simple exac...