搜索结果: 1-15 共查到“知识库 星系动力学”相关记录81条 . 查询时间(2.882 秒)
Meteor induced ridge and trough formation and the structuring of the nighttime E-region ionosphere
Meteor induced ridge trough formation
2017/3/22
When meteor-generated plasma trails diffuse into the
ionosphere they create large ambipolar electric fields
mainly perpendicular to the Earth’s geomagnetic field
(B) and extending many kilometers f...
碎石堆小行星的散体动力学建模与仿真方法综述
小行星探测 散体动力学 N体问题 碎石堆结构
2018/12/27
探测小行星将是未来几十年内航天界的研究热点. 现有资料表明小行星多为疏松多孔的碎石堆结构,易受探测活动的影响而破碎瓦解,因此对其探测必须先进行动力学建模,研究探测活动与小行星结构的相互作用,确保探测任务顺利执行. 在中国即将开展小行星探测任务的背景下,调研分析了散体动力学的研究和发展情况;并根据国内外的相关研究,对目前碎石堆小行星动力学模型与数值模拟方法的研究进行了综述;最后,结合小行星探测的应用...
Low mass stars and the structure of the Pleiades cluster
Low quality The Pleiades cluster Micron Near infrared photometric method The observatory
2014/12/9
This thesis presents a large scale search for new low mass members of the Pleiades cluster using near-infrared photometry from the Two Micron All Sky Survey and proper motions derived from digitized P...
The response of atomic and molecular gas to a disk -disk collision
Physical Atoms Molecules Gas Gas particles Mapping the atom Kinematics The stars
2014/12/9
The physical and morphological properties of the atomic and molecular gas in early stage interacting systems are investigated in detail using two complementary approaches; (1) by studying the response...
星团质量分层的探索途径
星团 质量分层 数据分析
2013/7/16
星团质量分层是指质量较大的恒星趋于向团中心集聚，而质量较小的恒星更多地分布在星团的外围部分。研究质量分层对理解星团的动力学演化规律以及约束大质量恒星的形成条件有重要意义。质量分层的探索无统一方法，往往因作者而异，但大体上可分为两条途径：即按不同天区探究成员星的质量分布，或者按不同质量范围探究成员星的空间分布。对常用的具体方法做了简单介绍和比较式讨论，并探讨了它们的适用范围。
Equation of State for Dark Energy in Modified Gravity Theories
Modified theories of gravity Dark energy Cosmology
2012/2/21
We explore the equation of state (EoS) for dark energy $w_{\mathrm{DE}}$ in modified gravitational theories to explain the current accelerated expansion of the universe. We explicitly demonstrate that...
A Density Independent Formulation of Smoothed Particle Hydrodynamics
Density Independent Formulation Smoothed Particle Hydrodynamics Cosmology and Extragalactic Astrophysics
2012/2/21
In the standard formulation of the smoothed particle hydrodynamics (SPH), it is assumed that the local density distribution is differentiable. This assumption is used to derive the spatial derivatives...
The Cosmological Constant in the Quantum Multiverse
Cosmological Constant Quantum Multiverse
2011/10/17
Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding globa...
Insights on the Formation, Evolution, and Activity of Massive Galaxies From Ultra-Compact and Disky Galaxies at z=2-3
Insights Formation Evolution Activity Massive Galaxies Disky Galaxies
2011/10/9
We present our results on the structure and activity of massive galaxies at z=1-3 using one of the largest (166 with M_star>=5e10 M_sun) and most diverse samples of massive galaxies derived from the G...
The effect of the environment on the gas kinematics and the structure of distant galaxies
Galaxies: evolution -galaxies: clusters -galaxies: kinematics and dynam- ics -galaxies: structure
2011/9/28
With the aim of distinguishing between possible physical mechanisms acting on galaxies when they fall into clusters, we study the properties of the gas and the stars in a sample of 422 emission-line g...
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...
Dark Matter and Charged Exotic Dust
Dark matter charged dust isothermal Lane-Emden equation
2011/10/18
The density profiles of dark matter halos are often modeled by an approximate solution to the isothermal Lane-Emden equation with suitable boundary conditions at the origin. It is shown here that such...
Large-scale clustering of galaxies in general relativity
Large-scale clustering galaxies general relativity
2011/10/17
Several recent studies have shown how to properly calculate the observed clustering of galaxies in a relativistic context, and uncovered corrections to the Newtonian calculation that become significan...
The long-term millimeter activity of active galactic nuclei
Galaxies: active — Quasars: general — Radiation mechanisms: non-thermal
2011/10/18
We analyze the long-term evolution of the fluxes of six active galactic nuclei (AGN) - 0923+392, 3C 111, 3C 273, 3C 345, 3C 454.3, and 3C 84 - in the frequency range 80-267 GHz using archival calibrat...
Hubble Space Telescope Pixel Analysis of the Interacting Face-on Spiral Galaxy NGC 5194 (M51A)
Hubble Space Telescope Pixel Analysis Interacting Face-on Spiral Galaxy NGC 5194 (M51A)
2011/10/19
A pixel analysis is carried out on the interacting face-on spiral galaxy NGC 5194 (M51A), using the HST/ACS images in the F435W, F555W and F814W (BVI) bands. After 4x4 binning of the HST/ACS images to...