共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
A. B. Rabiu I. A. Adimula K. Yumoto J. O. Adeniyi G. Maeda 《Earth, Moon, and Planets》2009,104(1-4):173-179
MAGDAS, the Magnetic Data Acquisition System, was successfully installed at the University of Ilorin, Nigeria—an equatorial station—in August 2006. MAGDAS is an important component of the International Heliophysical Year, IHY. We examined the preliminary results obtained from the analysis of the geomagnetic data obtained from the MAGDAS measurement. Diurnal variations of the solar quiet daily variation in the three geomagnetic elements, H, D, Z were studied. The obtained signatures of the magnetic field variations were discussed in the context of the literature. The day-to-day variability of the horizontal and vertical intensities as well as the declination of the geomagnetic field were examined. The study justified the need for a partner magnetic field observatory along same meridian as Ilorin, north or south of it, to facilitate synthesis of the equatorial electrojet effect. 相似文献
3.
4.
As a Philippine contribution to the International Heliophysical Year, we propose to use the MAGnetic Data Acquisition System/Circum Pan-Pacific Magnetometer Network (MAGDAS/CPMN), installed by the Space Environment Research Center (SERC), Kyushu University along the 210° magnetic meridian and the magnetic equator, to study the equatorial electrojet (EEJ) and counter electrojet (CEJ). Through this installation, it is made possible to observe geomagnetic field variations in real time. By utilizing this network of ground-based instruments, we hope to elucidate their regular day-to-day and seasonal variabilities and variations during magnetic storms and substorms. We also want to study the behavior of this ionospheric current system before, during, and after the occurrence of an earthquake. 相似文献
5.
随着天文技术的发展,天文数据处理软件的需求也不断更迭变化,导致软件运行环境渐趋复杂。对于开发者和使用者,急需提出一种对复杂天文数据处理软件敏捷化封装和部署的方法。我国明安图射电频谱日像仪已进入常规观测,与之配套的数据处理软件也已完成开发并投入使用。由于该软件的部署涉及操作系统环境、图形处理器运行环境及底层依赖软件等配置问题,导致安装过程既繁琐又容易出错。结合容器技术的特点,提出了一种基于Docker容器对日像仪软件系统进行敏捷封装与部署的方法,并对该方法的设计进行介绍,通过实验验证了其可用性,以及相比于传统虚拟机可获得较优异的性能表现。该方法可为未来天文数据处理软件的封装部署提供参考。可以预见,未来容器技术将成为天文海量数据处理的基础支撑技术。 相似文献
6.
平方千米阵列即将开始建设,各子工作包也进入关键设计评估阶段。基于云与容器技术是平方千米阵列科学数据处理器未来可能采用的平台技术。针对超大规模海量数据处理面临的天文应用软件快速部署、运行与实测要求,充分考虑天文应用软件运行环境复杂、云计算环境下超大规模计算集群部署困难等问题,系统研究并给出了一种使用容器技术的天文应用软件通用自动部署方法。以目前较为常用的可见度函数校准软件SAGECaL为例,首先分析了SAGECaL的相关特性和分布式部署方面存在的困难,进而给出了基于容器技术的SAGECaL分布式集群的自动部署方法。实验结果表明,自动部署方法极大地提高了SAGECaL分布式集群的部署效率,满足项目组承担平方千米阵列科学数据处理器相关测试工作所需要的基础平台部署与切换等需求,同时也为其它天文软件在云端的快速部署与执行提供了有益的思路。 相似文献
7.
8.
Valentin D. Ivanov G. Chauvin C. Foellmi M. Hartung N. Huélamo C. Melo D. Nürnberger M. Sterzik 《Astrophysics and Space Science》2006,304(1-4):247-249
The multiplicity of early-type stars is still not well established. The derived binary fraction is different for individual star forming regions, suggesting a connection with the age and the environment conditions. The few studies that have investigated this connection do not provide conclusive results. To fill in this gap, we started the first detailed adaptive-optic-assisted imaging survey of early-type field stars to derive their multiplicity in a homogeneous way. The sample has been extracted from the Hipparcos Catalog and consists of 341 BA-type stars within ∼300 pc from the Sun. We report the current status of the survey and describe a Monte-Carlo simulation that estimates the completeness of our companion detection. 相似文献
9.
P. A. Sturrock P. J. Baum J. M. Beckers C. E. Newman E. R. Priest H. Rosenberg D. F. Smith D. G. Wentzel 《Solar physics》1976,46(2):411-431
This report summarizes the proceedings of a meeting held on 17–20 September 1974, at Stanford University. The purpose was to explore plasma physics problems which arise in the study of solar physics. Sessions were concerned with specific questions including the following: Is the solar plasma thermal or non-thermal? What spectroscopic data are required? What types of magnetic field structures exist? Do MHD instabilities occur? Do resistive or non-MHD instabilities occur? What mechanisms of particle acceleration have been proposed? What information do we have concerning shock waves? Very few questions were answered categorically but, for each question, there was discussion concerning the observational evidence, theoretical analyses, and existing or potential laboratory and numerical experiments. 相似文献
10.
Tully-Fisher关系(TF关系)对于宇宙距离尺度和星系演化研究具有重要意义.对TF关系的发现史和嗣后的研究进展做了简要的评述,包括红外波段的TF关系、星系倾角问题、影响TF关系的若干因素、透镜星系的TF关系、重子TF关系、TF关系的宇宙学演化等. 相似文献
11.
J. Hughes D. D. Polojentsev C. Smith L. I. Yagudin 《Astrophysics and Space Science》1991,177(1-2):17-20
The status of the collaboration between the Pulkovo Observatory and the U.S. Naval Observatory (USNO) on the compilation of the Southern Reference Star (SRS) catalog is described. Results of comparisons between the data bases and the preliminary compiled SRS catalogs of the two observatories are discussed. Characteristics of the jointly compiled catalog are given. 相似文献
12.
基于目前流行的冷暗物质等级成团理论的星系形成的半解析模型取得了很大进展.在引入一系列合理的关于重子物质物理过程的假设,如气体冷却、恒星形成率、超新星能量反馈以后,结合N体数值模拟,星系形成的半解析模型一方面能较成功地预言许多与观测符合的近邻星系的性质,如光度函数、星系的两点相关函数、Thlly-Fisher关系、星系团中椭圆星系的颜色一星等关系等;另一方面还能较成功地预言宇宙的恒星形成历史,以及一部分高红移星系的性质,如Lyman-Break星系的数目随红移的分布.但是最近一些观测表明,半解析模型在高红移预言的大质量星系较少,且红星系数目也较观测少.重点讨论半解析模型成功与不足之处,并指出解决这些问题可能的途径。 相似文献
13.
M. J. LE BAS 《Meteoritics & planetary science》2001,36(9):1183-1188
Abstract— A report is presented for a possible revised classification of lunar igneous rocks that still uses the division of Moon rocks into mare and highland types. It subdivides the mare rocks into basalts depending on TiO2 content and glasses depending on colour, and subdivides the highland rocks principally into KREEP basalts and into coarse‐grained igneous rocks comparable to and using terrestrial igneous rock terminology. 相似文献
14.
15.
对银河系内卫星星系进行全面的"人口普查"具有重要的意义。目前已经发现了二十几个卫星星系,其光度范围分布很广,最暗的矮星系比球状星体还暗。叙述了卫星星系的光度分布、空间分布和动力学性质。总结了观测和理论研究进展,并讨论了星流和伽玛射线在研究银河系结构和暗物质性质方面的贡献。表明了卫星星系的统计分布能用来很好地限制冷暗物质理论和星系形成的相关物理过程,同时指出当前研究的局限性和可能的发展方向。 相似文献
16.
SS433是银河系内一个著名的高能天体,W50是它周围的超新星遗迹,自20世纪70年代末SS433的运动模型建立以来,已经受到了越来越多的关注,取得了丰富的多波段观测资料。但是,直到现在,关于这一系统的一些基本性质和参数还存在相当大的争论。该文介绍了关于SS433研究的某些新进展,主要包括SS433的运动模型和喷流的膨胀冷却模型,SS433的物质损失,各种时标的光变和喷流的结构,并对关于SS433研究的热点问题作了总结与展望。 相似文献
17.
Gilles Fontaine Elizabeth M. Green Pierre Brassard Stéphane Charpinet Pierre Chayer Malvina Billères Suzanna K. Randall Ben Dorman 《Astrophysics and Space Science》2004,291(3-4):379-386
We briefly review the recent advances that have been made on the front of pulsating subdwarf B (sdB) stars. The first family of sdB pulsators, the EC 14026 stars, was discovered a few years ago and consists of short-period (~100?200 s) p-mode variables. The second type of pulsating sdB’s consists of the PG 1716+426 stars, a group of variables showing long-period (~1 h) g-mode pulsations. The existence of the latter was first reported less than a year ago. While the two types of sdB pulsators differ markedly in their observational characteristics, we recently found a unifying property in the sense that the observed modes in these objects are excited through the same driving process, a classic kappa mechanism associated with the radiative levitation of iron in the stellar envelope. 相似文献
18.
19.
移动星团视差的精确测定对于宇宙距离尺度以及许多天体物理关系的研究起重要的定标作用。因此,在大约一个世纪的时间内,确定移动星团视差的方法一直处于不断改进之中。对此作了简要介绍和评述。 相似文献
20.
The role of the angular momentum in the regular or chaotic character of motion in an axially symmetric quasar model is examined.
It is found that, for a given value of the critical angular momentumL
zc
, there are two values of the mass of the nucleusM
n
for which transition from regular to chaotic motion occurs. The [L
zc
– M
n
] relationship shows a linear dependence for the time independent model and an exponential dependence for the evolving model.
Both cases are explained using theoretical arguments together with some numerical evidence. The evolution of the orbits is
studied, as mass is transported from the disk to the nucleus. The results are compared with the outcomes derived for galactic
models with massive nuclei. 相似文献