搜索结果: 1-15 共查到“天体物理学 Constraints”相关记录41条 . 查询时间(0.265 秒)
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 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...
Gyromagnetic Factors and Atomic Clock Constraints on the Variation of Fundamental Constants
Gyromagnetic Factors Atomic Clock Constraints Variation Fundamental Constants
2011/10/14
We consider the effect of the coupled variations of fundamental constants on the nucleon magnetic moment. The nucleon g-factor enters into the interpretation of the measurements of variations in the f...
Constraints on the origin of ultra-high-energy cosmic rays from cosmogenic neutrinos and photons
Astroparticle physics Acceleration of particles Abundances Neutrinos Gamma-rays Relativistic processes
2011/10/11
We study the production of cosmogenic neutrinos and photons during the extragalactic propagation of ultra-high-energy cosmic rays (UHECRs). For a wide range of models in cosmological evolution of sour...
Curvature perturbation spectra from waterfall transition, black hole constraints and non-Gaussianity
waterfall transition black hole constraints non-Gaussianity
2011/10/11
We carried out numerical calculations of a contribution of the waterfall field to the primordial curvature perturbation (on uniform density hypersurfaces) $\zeta$, which is produced during waterfall t...
Radio Interferometric Planet Search II: Constraints on sub-Jupiter-Mass Companions to GJ 896A
Interferometric Planet Constraints sub-Jupit
2011/10/10
We present results from the Radio Interferometric Planet (RIPL) search for compan- ions to the nearby star GJ 896A. We present 11 observations over 4.9 years. Fitting astrometric parameters to the dat...
Constraints on Enhanced Dark Matter Annihilation from IceCube Results
Dark matter Neutrinos Neutrino Telscopes
2011/10/18
Excesses on electromagnetic fluxes measured by ATIC, and the PAMELA and Fermi-LAT telescopes can be explained by dark matter annihilation in our Galaxy. However, this requires large boosts on the dark...
VHE gamma-ray Emission from Passive Supermassive Black Holes: Constraints for NGC 1399
Emission Passive Supermassive Black Holes
2011/9/28
Very high energy (VHE; >100 GeV) gamma-rays are expected to be emitted from the vicinity of super-massive black holes (SMBH), irrespective of their activity state. In the magnetosphere of rotating SMB...
The Stellar Archeology of the M33 Disk: Recent Star-Forming History and Constraints on the Timing of an Interaction with M31
galaxies evolution — galaxies spiral — galaxies
2011/8/24
Images recorded with MegaCam are used to investigate the recent star-forming history (SFH) of the Local Group Sc galaxy M33. The properties of the stellar disk change near R = 8 kpc. Within this radiu...
Cosmological Constraints on the Sign-Changeable Interactions
Cosmological Constraints the Sign-Changeable Interactions
2011/1/13
Recently, Cai and Su [Phys.\ Rev.\ D {\bf 81}, 103514 (2010)] argued that the sign of interaction $Q$ in the dark sector changed in the approximate redshift range of $0.45\,\lsim\, z\,\lsim\, 0.9$, by...
Constraints on a hadronic model for unidentified off-plane galactic gamma-ray sources
hadronic model unidentified off-plane galactic gamma-ray sources
2011/1/10
Recently the H.E.S.S. collaboration announced the detection of an unidentified gamma-ray source with an off-set from the galactic plane of 3.5 degrees: HESS J1507-622. If the distance of the object is...
Future CMB Constraints on Early, Cold, or Stressed Dark Energy
Future CMB Constraints on Early Cold Stressed Dark Energy
2011/1/11
We investigate future constraints on early dark energy (EDE) achievable by the Planck and CMBPol experiments, including cosmic microwave background (CMB) lensing. For the dark energy, we include the p...
The Supernova Legacy Survey 3-year sample: Type Ia Supernovae photometric distances and cosmological constraints
The Supernova Legacy Survey 3-year sample Type Ia Supernovae photometric distances
2011/1/10
We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15 < z < 1.1) discovered during the first three years of the Supernova Legacy Survey (SNLS). Thes...
Swift observation of Segue 1: constraints on sterile neutrino parameters in the darkest galaxy
Swift observation constraints on sterile neutrino parameters
2011/1/10
Some extensions of standard particle physics postulate that dark matter may be partially composed of weakly interacting sterile neutrino particles that have so far eluded detection. We use a short (~5...