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Dark Matter Constraints from the Sagittarius Dwarf and Tail System
the Sagittarius Dwarf Tail System
2014/12/24
2MASS has provided a three-dimensional map of the >360 degree, wrapped tidal tails of the Sagittarius (Sgr) dwarf spheroidal galaxy, as traced by M giant stars. With the inclusion of radial velocity d...
Galaxies in a simulated Lambda CDM universe - II. Observable properties and constraints on feedback
feedback cluster
2014/12/23
We compare the properties of galaxies that form in a cosmological simulation without strong feedback to observations of the z= 0 galaxy population. We confirm previous findings that models without str...
Joint spectral-timing modelling of the hard lags in GX 339-4: constraints on reflection models
Joint spectral-timing modelling the hard lags GX 339-4 constraints reflection models
2012/2/23
The X-ray variations of hard state black hole X-ray binaries above 2 keV show 'hard lags', in that the variations at harder energies follow variations at softer energies, with a time-lag \tau dependin...
Future constraints on variations of the fine structure constant from combined CMB and weak lensing measurements
Future constraints variations fine structure constant combined CMB weak lensing measurements
2012/2/21
We forecast the ability of future CMB and galaxy lensing surveys to constrain variations of the fine structure constant. We found that lensing data, as those expected from satellite experiments as Euc...
Constraints on the Lifetimes of Disks Resulting from Tidally Destroyed Rocky Planetary Bodies
circumstellar matter minor planets asteroids general planetary systems abundances white dwarfs
2012/2/23
Spitzer IRAC observations of 15 metal-polluted white dwarfs reveal infrared excesses in the spectral energy distributions of HE 0110-5630, GD 61, and HE 1349-2305. All three of these stars have helium...
On the prior dependence of constraints on the tensor-to-scalar ratio
infl ation, primordial gravitational waves (theory), cosmological parameters from CMBR
2011/10/9
We investigate the prior dependence of constraints on cosmic tensor perturbations. Commonly imposed is the strong prior of the single-field inflationary consistency equation, relating the tensor spect...
Constraints on dissipative unified dark matter
Dark Matter, Dark Energy, Gravitational potential, bulk viscosity, Eckart’s theory
2011/9/28
Modern cosmology suggests that the Universe contains two dark components -- dark matter and dark energy -- both unkown in laboratory physics and both lacking direct evidence. Alternatively, a unified ...
The Effect of Local Dark Matter Substructure on Constraints in Sommerfeld-Enhanced Models
Effect Local Dark Matter Substructure Constraints Sommerfeld-Enhanced Models
2011/10/17
In models of dark matter with Sommerfeld-enhanced annihilation, where the annihilation rate scales as the inverse velocity, models of local substructure motivated by N-body dark matter simulations imp...
Constraints on the Synchrotron Shock Model for the Fermi GBM Gamma-Ray Burst 090820A
Constraints Synchrotron Shock Model Fermi GBM Gamma-Ray Burst 090820A
2011/10/18
Discerning the radiative dissipation mechanism for prompt emission in Gamma-Ray Bursts (GRBs) requires detailed spectroscopic modeling that straddles the $\nu F_{\nu}$ peak in the 100 keV - 1 MeV rang...
Improved Constraints on Type Ia Supernova Host Galaxy Properties using Multi-Wavelength Photometry and their Correlations with Supernova Properties
Improved Constraints Supernova Galaxy Properties Multi-Wavelength Photometry Correlations Supernova Properties
2011/10/18
We improve estimates of stellar mass and mass-weighted average age of Type Ia supernova (SN Ia) host galaxies by combining UV and near-IR photometry with optical photometry in our analysis. Using 206 ...
Dark Matter distribution in the Milky Way: microlensing and dynamical constraints
Dark Matter distribution Milky Way microlensing dynamical constraints
2011/10/20
We show that current microlensing and dynamical observations of the Galaxy allow to set interesting constraints on the Dark Matter local density and profile slope towards the galactic centre. Assuming...
WMAP 7 year constraints on CPT violation from large angle CMB anisotropies
CMBR theory CMBR experiments
2011/10/18
We constrain the rotation angle $\alpha$ of the linear polarization of CMB photons using the large angular scale (up to $\sim 4^\circ$) signal in WMAP 7 year data. At these scales, the CMB polarizatio...
Features in the primordial spectrum: new constraints from WMAP7+ACT data and prospects for Planck
Features primordial spectrum constraints WMAP7+ACT data prospects Planck
2011/10/19
We update the constraints on possible features in the primordial inflationary density perturbation spectrum by using the latest data from the WMAP7 and ACT Cosmic Microwave Background experiments. The...
Stellar Evolution Constraints on the Triple-Alpha Reaction Rate
Stellar Evolution Constraints Triple-Alpha Reaction Rate
2011/10/19
We investigate the quantitative constraint on the triple-alpha reaction rate based on stellar evolution theory, motivated by the recent significant revision of the rate proposed by nuclear physics cal...
Constraints from the CMB temperature and other common observational data-sets on variable dark energy density models
Cosmology Dark energy Thermodynamics
2011/10/13
The thermodynamic and dynamical properties of a variable dark energy model with density scaling as rho_x \propto (1+z)^m, z being the redshift, are discussed following the outline of Jetzer et al. Thi...