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Three Types Of Extreme-Energy Space Particles May Have Unified Origin（图）
Three Types Extreme-Energy Space Particles Unified Origin
2018/2/1
One of the biggest mysteries in astroparticle physics has been the origins of ultrahigh-energy cosmic rays, very high-energy neutrinos, and high-energy gamma rays. Now, a new theoretical model reveals...
New Theory Turns Back Clock on Conditions Behind Universe's Origin
Turns Back Clock Universe's Origin
2016/2/22
In a new study, scientists from The University of Texas at Dallas and their colleagues suggest a novel way for probing the beginning of space and time, potentially revealing secrets about the conditio...
Origin Of Coronal High Temperature
center temperature gasification substances bian sphere coronal high
2015/6/2
In sun center, pressure least direction is ends of sun spin axis. Thus, sun center ultra-high temperature gasification substance jet out along sun's rotation axis, through photosphere, chromosphere, t...
The Origin of the Dust Arch in the Halo of NGC 4631: An Expanding Superbubble?
NGC 4631 galaxies
2014/12/24
We study the nature and the origin of the dust arch in the halo of the edge-on galaxy NGC 4631 detected by Neininger & Dumke. We present CO observations made using the new on-the-fly mapping mode with...
We show that a Magellanic Cloud origin for the warp of the Milky Way can explain most quantitative features of the outer H I layer recently identified by Levine et al. We construct a model, similar to...
On the origin of cold dark matter halo density profiles
dark matter large-scale structure of the universe
2014/12/24
N-body simulations predict that cold dark matter (CDM) halo-assembly occurs in two phases: (i) a fast-accretion phase with a rapidly deepening potential well; and (ii) a slow-accretion phase character...
THE SINGLE-DEGENERATE BINARY ORIGIN OF TYCHO'S SUPERNOVA AS TRACED BY THE STRIPPED ENVELOPE OF THE COMPANION
X-ray arc Tycho's supernova
2014/12/20
We propose that a nonthermal X-ray arc inside the remnant of Tycho's supernova (SN) represents the interaction between the SN ejecta and the companion star's envelope lost in the impact of the explosi...
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...
Broad Line Radio Galaxies Observed with Fermi-LAT: The Origin of the GeV Gamma-Ray Emission
Broad Line Radio Galaxies Fermi-LAT:OriginGeV Gamma-Ray Emission
2011/10/10
We report on a detailed investigation of the gamma-ray emission from 18 broad line radio galaxies (BLRGs) based on two years of Fermi Large Area Telescope (LAT) data. We confirm the previously reporte...
Quantum Origin of the Primordial Fluctuation Spectrum and its Statistics
Quantum Origin Primordial Fluctuation Spectrum Statistics
2011/10/9
The account of the origin of cosmic structure, as provided by the standard inflationary paradigm, is not fully satisfactory, as has been argued in Perez et al 2006. The central point of that work is t...
A Model for the Origin of High Density in Loop-top X-ray Sources
Model Origin Density Loop-top X-ray Sources
2011/10/8
Super-hot looptop sources, detected in some large solar flares, are compact sources of HXR emission with spectra matching thermal electron populations exceeding 30 megakelvins. High observed emission ...
Nuclear astrophysics: the unfinished quest for the origin of the elements
Nuclear astrophysics:unfinished quest origin elements
2011/10/8
Half a century has passed since the foundation of nuclear astrophysics. Since then, this discipline has reached its maturity. Today, nuclear astrophysics constitutes a multidisciplinary crucible of kn...
Nucleosynthesis during the Merger of White Dwarfs and the Origin of R Coronae Borealis Stars
Dwarfs Origin Borealis Stars
2011/10/8
Many hydrogen deficient stars are characterised by surface abundance patterns that are hard to reconcile with conventional stellar evolution. Instead, it has been suggested that they may represent the...
Quantum fluctuations in planar domain-wall space-times: A possible origin of primordial preferred direction
Quantum fluctuations planar domain-wall space-times possible origin primordial preferred direction
2011/10/18
We study the gravitational effects of a planar domain wall on quantum fluctuations of a massless scalar field during inflation. By obtaining an exact solution of the scalar field equation in de Sitter...
The origin of RXJ1856.5-3754 and RXJ0720.4-3125 -- updated using new parallax measurements
stars: kinematics – pulsars: individual: RXJ1856.5-3754 – pulsars: individual
2011/9/29
RXJ1856 and RXJ0720 are the only young isolated radio-quiet neutron stars (NSs) for which trigonometric parallaxes were measured. Due to detection of their thermal emission in X-rays they are importan...