搜索结果: 31-45 共查到“知识库 运动宇宙学”相关记录107条 . 查询时间(1.25 秒)
On the Lx-L6micron ratio as a diagnostic for Compton-thick AGN
X-rays: general X-rays: diuse background X-rays: galaxies Infrared: galaxies
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2011/10/11
As the mid-IR luminosity represents a good isotropic proxy of the AGN power, a low X-ray to mid-IR luminosity ratio is often claimed to be a reliable indicator for selecting Compton-thick (CT) AGN. We...
The Young, the Old, and the Dusty: Stellar Populations of AGN Hosts
Dusty: Stellar Populations AGN Hosts
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2011/10/11
Studying the average properties of active galactic nuclei (AGN) host stellar populations is an important step in understanding the role of AGN in galaxy evolution and the processes which trigger and f...
Observation of the Cosmic Ray Moon shadowing effect with the ARGO-YBJ experiment
Extensive Air Showers, Cosmic Rays, Moon shadow, Geomagnetic fi eld, ARGO-YBJ
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2011/10/10
Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called \emph{Moon shadow}). The Moon shadow is an important tool to determine the performance of an air shower a...
Inflation and primordial non-Gaussianities of "generalized Galileons"
Inflation primordial non-Gaussianities
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2011/10/9
We set up cosmological perturbation theory and study the cosmological implications of the so-called `generalized Galileon' developed in \cite{Deffayet:2011gz,horndeski}.This is the most general scalar...
Evolution and Distribution of Magnetic Fields from AGNs in Galaxy Clusters II. The Effects of Cluster Size and Dynamical State
Galaxy Clusters Effects Cluster Size Dynamical State
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2011/10/9
Theory and simulations suggest that magnetic fields from radio jets and lobes powered by their central super massive black holes can be an important source of magnetic fields in the galaxy clusters. T...
Renegade Subhaloes in the Local Group
cosmology: theory – cosmology: dark matter – methods: N-body simulations –galaxies: Local Group – galaxies: Magellanic Clouds
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2011/10/9
Using a dark matter only Constrained Local UniversE Simulation (CLUES) we examine the existence of subhaloes that change their affiliation from one of the two prominent hosts in the Local Group (i.e. ...
Adaptive gravitational softening in GADGET
gravitation – methods: numerical – cosmology: theory, large-scale struc- ture of Universe
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2011/10/9
Cosmological simulations of structure formation follow the collisionless evolution of dark matter starting from a nearly homogeneous field at early times down to the highly clustered configuration at ...
Statistical Anisotropy and the Vector Curvaton Paradigm
Statistical Anisotropy Vector Curvaton Paradigm
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2011/10/17
The vector curvaton paradigm is reviewed. The mechanism allows a massive vector boson field to contribute to or even generate the curvature perturbation in the Universe. Contribution of vector bosons ...
Dense DM clumps seeded by cosmic string loops and DM annihilation
dark matter cosmic string cosmology
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2011/10/9
The annihilation of the dark matter in clumps around cosmic string loops is studied. These clumps form at the radiation dominated stage and may have densities \gg\rho_{eq}. We conclude that 100 GeV ne...
HST-ACS photometry of the isolated dwarf galaxy VV124=UGC4879. Detection of the Blue Horizontal Branch and identification of two young star clusters
Galaxies: dwarf — Galaxies: Local Group — Galaxies: structure — Galaxies: stellar content — Galaxies: ISM —Galaxies: individual
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2011/10/8
We present deep V and I photometry of the isolated dwarf galaxy VV124=UGC4879, obtained from archival images taken with the Hubble Space Telescope - Advanced Camera for Surveys. In the color-magnitude...
Domain wall solution in $F(R)$ gravity and variation of the fine structure constant
solution gravity variation fine structure
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2011/10/18
We construct a domain wall solution in $F(R)$ gravity. We first compare a scalar field theory having a runaway type potential with a corresponding scalar field theory obtained through a conformal tran...
Who discovered the expanding universe?
discovered expanding universe
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2011/10/18
Who discovered the expanding universe? Was it Hubble, or Lemaitre, or was it just the end result of a long series of investigations? In this article we summarise the main steps and contributions that ...
Scalar field description of a parametric model of dark energy
Scalar field description parametric model dark energy
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2011/10/9
We investigate theoretical and observational aspects of a time-dependent parameterization for the dark energy equation of state (EoS) $w(z)$, which is a well behaved function of the redshift $z$ over ...
Cosmic Bubble Collisions
Cosmic Bubble Collisions
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2011/10/9
I briefly review the physics of cosmic bubble collisions in false-vacuum eternal inflation. My purpose is to provide an introduction to the subject for readers unfamiliar with it, focussing on recent ...
Search for Nuclei Sources in the Ultra-High Energy Cosmic Ray Data
Ultra-High Energy Cosmic Rays Galactic Magnetic Field
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2011/10/8
We present a new method to search for heavy nuclei sources, on top of background, in the Ultra-High Energy Cosmic Ray data. We apply it to the 69 events with energies E>55 EeV published by the Pierre ...