搜索结果: 1-15 共查到“halo”相关记录98条 . 查询时间(0.156 秒)
Astronomers detect dark matter halo around ancient dwarf galaxy（图）
Astronomers detect dark matter halo ancient dwarf galaxy
2021/3/5
The Milky Way is surrounded by dozens of dwarf galaxies thought to be relics of the first galaxies in the universe. Among the most primitive of these galactic fossils is Tucana II -- an ultrafaint dwa...
Giant magnetic ropes seen in Whale Galaxy's halo（图）
Giant magnetic ropes seen Whale Galaxy halo
2020/1/4
Using the National Science Foundation's Karl G. Jansky Very Large Array radio telescope, a team of astronomers has captured for the first time an image of large-scale, coherent, magnetic fields in the...
Halo: Recursive Proof Composition without a Trusted Setup
zero knowledge elliptic curve cryptosystem
2019/9/16
Non-interactive proofs of knowledge allow us to publicly demonstrate the faithful execution of arbitrary computations. SNARKs have the additional property of succinctness, meaning that the proofs are ...
Massive Primordial Galaxies Found In ‘Halo’ Of Dark Matter（图）
Massive Primordial Galaxies Halo Dark Matter
2017/12/19
Observations of two galaxies made with the National Science Foundation-funded Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope suggest that large galaxies formed faster than scienti...
VLA Gives New Insight Into Galaxy Cluster’s Spectacular “Mini-Halo”
VLA Galaxy Cluster’s Spectacular Mini-Halo
2017/7/21
Astronomers using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) have discovered new details that are helping them decipher the mystery of how giant radio-emitting structures ...
面向月球中继卫星工程轨道设计需求，研究解析计算方法在地月系L2点halo轨道设计中的应用问题。在讨论圆型限制性三体问题三阶解析近似计算方法的基础上，分析了解析计算与数值计算的差异，给出了解析近似计算在工程约束下的适用范围，进而提出了基于解析计算的轨道设计和特征筛选方法。分别采用解析初值和数值初值进行halo轨道外推，比对验证采用解析计算设计轨道的可行性。研究结果表明,解析计算方法适用于月球中继卫星...
不同月球借力约束下的地月Halo轨道转移轨道设计
Halo轨道 不变流形 借力飞行 混合优化
2016/3/2
针对地月系L2点不同任务需求下的低耗能转移轨道设计问题，基于不变流形理论与混合优化技术，深入研究了不同月球借力约束与不同幅值Halo轨道的入轨点（简称HOI点）对转移轨道飞行时间与燃料消耗的影响，给出了HOI点选择策略。首先结合任务要求并考虑月球引力影响，在月球借力点施加不同约束条件，通过微分修正算法调整Halo轨道的稳定流形，设计月球到Halo轨道的转移轨道。采用遗传算法与微分修正算法相结合的混...
不同月球借力约束下的地月Halo轨道转移轨道设计
Halo轨道 不变流形 借力飞行 混合优化
2016/3/2
针对地月系L2点不同任务需求下的低耗能转移轨道设计问题，基于不变流形理论与混合优化技术，深入研究了不同月球借力约束与不同幅值Halo轨道的入轨点（简称HOI点）对转移轨道飞行时间与燃料消耗的影响，给出了HOI点选择策略。首先结合任务要求并考虑月球引力影响，在月球借力点施加不同约束条件，通过微分修正算法调整Halo轨道的稳定流形，设计月球到Halo轨道的转移轨道。采用遗传算法与微分修正算法相结合的混...
Astrophysicists produce the first age map of the halo of the Milky Way
Astrophysicists first age map Milky Way
2015/11/12
University of Notre Dame astronomer Timothy Beers and his Galactic Archaeology group, which includes Notre Dame astronomers Daniela Carollo and Vinicius Placco, have led an international team of resea...
日地Halo轨道的多约束转移轨道分层微分修正设计
分层微分修正 转移轨道 多约束条件
2015/11/10
针对日-地系统L1点（简称SEL1点）Halo轨道转移轨道设计中存在的多约束与初值敏感性问题，提出一种基于分层微分修正与初值多项式的设计方法。首先定义平动点转移轨道设计过程中存在的约束条件，然后根据不同的终端约束条件，重点给出了同时考虑轨道高度、轨道倾角、升交点赤经与航迹角等多约束条件下的分层微分修正方法。通过分析约束变量与控制变量之间的关系，得到能够解决微分修正初值问题的初值表达式。最后在多约束...
Bar-driven dark halo evolution: A resolution of the cusp-core controversy
theory dark matter
2014/12/26
Simulations predict that the dark matter halos of galaxies should have central cusps, while those inferred from observed galaxies do not have cusps. We demonstrate, using both linear perturbation theo...
Chandra Observation of the Edge-on Galaxy NGC 3556 (M108): Violent Galactic Disk-Halo Interaction Revealed
NGC 3556 spiral
2014/12/26
We present a 60 ks Chandra ACIS-S observation of the isolated edge-on spiral galaxy NGC 3556, together with a multiwavelength analysis of various discrete X-ray sources and diffuse X-ray features. Amo...
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...
The halo occupation distribution (HOD) describes the bias between galaxies and dark matter by specifying (1) the probability P(N|M) that a halo of virial mass M contains N galaxies of a particular cla...
Theoretical models of the halo occupation distribution: Separating central and satellite galaxies
formation halos
2014/12/24
The halo occupation distribution (HOD) describes the relation between galaxies and dark matter at the level of individual dark matter halos. The properties of galaxies residing at the centers of halos...