| 1. | Then , we analyse in detail the mass - accretion histories and structural properties of dark haloes in high - resolution n - body simulations 本文利用高分辨率的n体数值模拟仔细分析了暗晕的质量吸积历史和内部结构演化历史。 |
| 2. | Since the scaling relation we found is intrinsic , this application is independant of how we define haloes , when we do observation and which cosmogony we choose 另外我们发现:暗晕汇聚因子c的增长并不是简单地正比于宇宙膨胀因子,而与质量吸积速率反相关。 |
| 3. | Our results are much helpful for us to understand the building - up mechanism of the universal density profile , galaxy formation and high redshift tully - fisher relation 这些结果对我们解释暗晕的普适密度轮廓,高红移盘星系的瓜111卜f讨ler关系和理解星系核球及盘的形成都有很大帮助 |
| 4. | We model the density distribution in individual haloes using the nfw profile . for a given halo , there is a tight correlation between its inner scale radius rs and the mass within it 我们运用nfw轮廓来拟合暗晕的密度分布,进而发现:内部特征半径r _ s和其内质量m _ s的演化非常密切地相关。 |
| 5. | With a reasonable choice for these two parameters , our model predicts an occupation number distribution of galaxies in halos which agrees very well with the predictions of semi - analytical models 通过适当选择这两个参量,模型预言的暗晕中星系的分布函数和半解析模型的结果符合得非常好。 |
| 6. | These two phases are separated at a time when the halo concentration parameter c ~ 5 and the binding energy of the halo is approximately equal to that of a singular isothermal sphere with the same circular velocity 肠‘随时间的增长和宇宙的膨胀速率基本一致: ( 2 )在这两个阶段的分界点处暗晕的汇聚因子。 |
| 7. | Ms , for all its main progenitors , which is the basic reason why halo structural properties are closely related to their mass - accretion histories . this correlation can be used to predict the structural properties of a dark halo at any time in its history 我们建立了模型,利用该相关关系和暗晕质量吸积历史来预言其内部结构的演化,该方法无论从统计上还是对单个暗晕均达到了很高的精度。 |
| 8. | We find that within a given cosmological model different schemes of galaxy formation lead to significant changes of the pvd . we propose a simple phenomological model for the formation of lyman break galaxies , determined by the formation interval parameter z and the halo mass threshold mh 首先,我们提出了一个简单唯象模型来联系宇宙学n体数值模拟和lymanbreak星系,该模型由两个参量(形成时间间隔_ z和暗晕质量下限m _ h )唯一确定。 |
| 9. | Haloes in the two accretion phases show systematically different properties , for example , the circular velocity vh increases rapidly with time and approximately equals the inner circular velocity vs in the fast accretion phase , but remain almost constant and less than vs in the slow accretion phase : the inner properties of a halo , such as rs and ms increase rapidly with time in the fast accretion phase but change only slowly in the slow accretion phase : the halo concentration changes slow in the fast accretion phase , but increases rapidly with the hubble expansion in the slow accretion phase . the inner structure and potential well associated with a halo is built up mainly in the fast accretion phase , while a large amount of mass can be accreted in the slow accretion phase without changing significantly the inner properties and the potential well ~ 4 ,其束缚能和具有相同圆周速度的等温球大致相等; ( s )在这两个阶段,暗晕的行为特征迥异(例如,圆周速度均‘在快速吸积阶段增长迅速且略大于内部圆周速度: 、 ,而在缓慢吸积阶段基本恒定甚至降低,且小于、 、 . : 、和呱在快速吸积阶段增长迅猛,而在缓慢吸积阶段增长滞缓) : ( l )一个暗晕的内部结构和引力势阱主要是在早期的快速吸积阶段成长起来的,虽然在缓慢增长阶段可以吸积大量的质量(超过10倍) ,但这并不显著地改变其内部特征和引力势阱 |
| 10. | The build - up of dark haloes in cdm models generally consists of an early phase of fast accretion [ where the halo mass mh increases with time much faster than the expansion rate of the universe ] and a late phase of slow accretion [ where mh increases with time approximately the same as the expansion rate ] 我们同时发现: ( 1 )冷暗物质模型( cdm )中暗晕的成长均包括一个早期的快速吸积阶段[暗晕质量m _ h随时间的增长远快于宇宙的膨胀速率和一个晚期的缓慢吸积阶段 |