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Mechanics of the Gyroscopic Precession and Calculation of the Galactic Mass
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作者 Jian Sun Ting Xu +1 位作者 Zheng Jiao Hui Wang 《Journal of Modern Physics》 2022年第1期34-45,共12页
A spinning gyroscope precesses about the vertical due to a torque acting upon the wheel. The torque is generated by the shift of moment of force by gravity and it points to the vertical instead of the tangential direc... A spinning gyroscope precesses about the vertical due to a torque acting upon the wheel. The torque is generated by the shift of moment of force by gravity and it points to the vertical instead of the tangential direction of precession. This intuition offers an alternative and straightforward view of precession dynamics in comparison with the literature. It also presumes a dynamic balance of momentum between circular motions of the wheel spin and precession. Accordingly, the gyroscopic dynamics is then applied to the study of galactic motion of the solar system in space and the Galactic mass is calculated with the inclusion of gyroscopic effect of the solar planets. Results indicate that the gyroscopic effect of Mercury orbiting around the Sun can increase the calculated Galactic mass by 23% in comparison with the result obtained by the classic approach. 展开更多
关键词 Gyroscopic Precession Solar System galactic mass
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银河系质量的多途径测定
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作者 赵君亮 《天文学进展》 CSCD 北大核心 2015年第2期175-187,共13页
对测定银河系质量的一些主要方法及若干重要相关问题做了简要介绍,包括运动学方法(含自转曲线法)、伴天体的潮汐半径、逃逸速度法和计时推理法等。给出近40年来较有代表性的银河系质量的实测结果,并加以比较和讨论。迄今为止银河系质量... 对测定银河系质量的一些主要方法及若干重要相关问题做了简要介绍,包括运动学方法(含自转曲线法)、伴天体的潮汐半径、逃逸速度法和计时推理法等。给出近40年来较有代表性的银河系质量的实测结果,并加以比较和讨论。迄今为止银河系质量的测定值仍有相当大的不确定性,未来的空间观测资料有望对此做出明显的改进。 展开更多
关键词 银河系质量 暗物质 自转曲线 潮汐半径 逃逸速度 计时推理 自行
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The Origin, Properties and Detection of Dark Matter and Dark Energy
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作者 Sylwester Kornowski 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第2期749-774,共26页
The pictures from the James Webb Space Telescope (JWST) suggest that massive galaxies were already at the beginning of the expansion of the Universe because there was too short time to create them. It is consistent wi... The pictures from the James Webb Space Telescope (JWST) suggest that massive galaxies were already at the beginning of the expansion of the Universe because there was too short time to create them. It is consistent with the new cosmology presented within the Scale-Symmetric Theory (SST). The phase transitions of the initial inflation field described in SST lead to the Protoworld—its core was built of dark matter (DM). We show that the DAMA/LIBRA annual-modulation amplitude forced by the change of the Earth’s velocity (i.e. baryonic-matter (BM) velocity) in relation to the spinning DM field in our Galaxy’s halo should be very low. We calculated that in the DM-BM weak interactions are created single and entangled spacetime condensates with a lowest mass/energy of 0.807 keV—as the Higgs boson they can decay to two photons, so we can indirectly detect DM. Our results are consistent with the averaged DAMA/LIBRA/COSINE-100 curve describing the dependence of the event rate on the photon energy in single-hit events. We calculated the mean dark-matter-halo (DMH) mass around quasars, we also described the origin of the plateaux in the rotation curves for the massive spiral galaxies, the role of DM-loops in magnetars, the origin of CMB, the AGN-jet and galactic-halo production, and properties of dark energy (DE). 展开更多
关键词 New Cosmology Dark Matter DM-BM Weak Interactions DMH mass around Quasars Rotation Curves of Galaxies MAGNETARS CMB AGN-Jet Production galactic-Halo Production Dark Energy
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The central black hole masses for the γ-ray loud blazars 被引量:6
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作者 YANG JiangHe FAN JunHui 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2010年第10期1921-1927,共7页
The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST) provides an increase in sensitivity and has detected rapid variability of gamma-ray sources.The variability time scales detected f... The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST) provides an increase in sensitivity and has detected rapid variability of gamma-ray sources.The variability time scales detected from the gamma-ray loud blazars by LAT and EGRET,and gamma-ray luminosity are used to estimate the central black hole masses.In this work,we find that the lower limits of central black hole masses are in a range of (0.3-24)×107M⊙,which are compared with those obtained by other authors.Our results are consistent with other authors' results.Also,the Lorentz factor,Γ,and the propagation angle,θ,are obtained for 18 blazars for which superluminal motions are known. 展开更多
关键词 active galactic nuclei(AGNs) time scale central black hole mass Doppler factor
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Do Near-Solar-System Supernovae Enhance Volcanic Activities on Earth and Neighbouring Planets on Their Paths through the Spiral Arms of the Milky Way, and What Might Be the Consequences for Estimations of Earth’s History and Predictions for Its Future? 被引量:3
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作者 Heinz-Juergen Brink 《International Journal of Geosciences》 2019年第5期563-575,共13页
Recent observations of young volcanism on the near-Earth terrestrial planets require a new understanding. Magmatic/volcanic episodes on Venus, Mars and Mercury, as well as on Earth’s Moon, are apparently contemporane... Recent observations of young volcanism on the near-Earth terrestrial planets require a new understanding. Magmatic/volcanic episodes on Venus, Mars and Mercury, as well as on Earth’s Moon, are apparently contemporaneous thermal events that accompanied increased magmatic/volcanic activity on Earth, following a 300-Myr cycle. A collateral galactic thermal source in the Milky Way appears to be needed that would predominantly affect the interior of the planets and, perhaps indirectly, Earth’s biosphere, compared to other galactic sources, such as intense cosmic rays or large, rocky bolides. The search for such a source leads to near-Earth supernovae, with their neutrino output, and to the question of whether those neutrinos could act as energy transmitters to heat up the body of Earth, and also enhance its short-term magmatic processes;for example, Cenozoic anorogenic volcanism. This observation challenges present assumptions and paradigms about Earth’s history, and requires the following reconsiderations: 1) the real origin of the end-Cretaceous mass extinction;2) the general radioactive age determinations of rocks;and 3) geodynamic modelling using additional, external heat sources. 展开更多
关键词 Synchronous Planetary MAGMATISM galactic Heat Source SUPERNOVAE and White DWARFS NEUTRINOS mass EXTINCTIONS
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Light Speed Expansion and Rotation of a Very Dark Machian Universe Having Internal Acceleration
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作者 U. V. S Seshavatharam S. Lakshminarayana 《International Journal of Astronomy and Astrophysics》 2020年第3期247-283,共37页
We present a Machian model of Quantum Cosmology with full dark matter and light speed expansion and rotation. During galaxy formation and evolution, fraction of dark matter transforms to visible matter with a relation... We present a Machian model of Quantum Cosmology with full dark matter and light speed expansion and rotation. During galaxy formation and evolution, fraction of dark matter transforms to visible matter with a relation of the form, m_vis = constant * (m_dark)<sup>2/3</sup>. Using this relation and replacing MOND’s “critical acceleration” with “current cosmic maximum angular acceleration”, galactic flat rotation speed range of (50 to 500) km/sec can be fitted well. Estimated flat rotation speeds of DD168, Milky Way and UGC12591 are 49.96 km/sec, 199.66 km/sec and 521.75 km/sec respectively. Based on these striking coincidences, it is possible to say that, MOND’s approach is implicitly connected with cosmological estimation of 95% invisible matter. With reference to SPARC data for flat rotation speeds and current cosmic maximum angular acceleration, galactic total mass can be estimated. Considering galactic total mass, galactic visible mass and dark mass can be estimated. Proceeding further, galactic working radii, angular velocity and visible matter density can be estimated. Estimated Milky Way’s effective radius is 293 kpc. Even though, this model is free from “big bang”, “inflation”, “dark energy”, “flatness” and “red shift” issues, at 2.722 K, estimated present Hubble parameter is 66.24 km/sec/Mpc, cosmic radius is 146.3 times of the Hubble radius, angular velocity is 146.3 times lower than the Hubble parameter and cosmic age is 146.3 times of the Hubble age. With future observations and advanced telescopes, it may be possible to see far distant galaxies and very old stars far beyond the current observable cosmic radius. 展开更多
关键词 Planck Scale Machian Universe Speed of Light galactic Dark Matter galactic Visible mass galactic Visible mass Density Cosmic Anisotropy galactic Internal Acceleration Cosmic Graviton Wavelength
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活动星系核中黑洞质量与宇宙学红移的研究 被引量:4
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作者 董霞 张皓辉 +1 位作者 熊定荣 张雄 《云南师范大学学报(自然科学版)》 2013年第1期9-12,共4页
收集了209个活动星系核(46个平谱射电类星体,78个BL Lac天体,85个射电星系)样本,估算出爱丁顿吸积率,讨论了黑洞质量、热光度、红移量和爱丁顿吸积率之间的关系,得出了以下结论:(1)活动星系核的一个演化序列为:平谱射电类星体(FSRQ)——... 收集了209个活动星系核(46个平谱射电类星体,78个BL Lac天体,85个射电星系)样本,估算出爱丁顿吸积率,讨论了黑洞质量、热光度、红移量和爱丁顿吸积率之间的关系,得出了以下结论:(1)活动星系核的一个演化序列为:平谱射电类星体(FSRQ)——BL Lac天体——射电星系(RG)的演化;(2)三类星体的中心黑洞质量、红移量和热光度有较大差异:皆为FSRQ>BL Lac>RG;(3)吸积率与热光度之间的相关性很强,吸积率的变化将导致热光度的变化。 展开更多
关键词 活动星系核 中心黑洞质量 红移量 热光度 爱丁顿吸积率
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Galactic Route to the Strong Coupling Constant αs(mz) and Its Implication on the Mass Constituents of the Universe
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作者 Hans Hermann Otto 《Journal of Applied Mathematics and Physics》 2022年第12期3572-3585,共14页
Some fundamental physical quantities need an alternative description. We derive the word average value of interaction coupling constant α<sub>s</sub>(m<sub>z</sub>) from the observed maximum g... Some fundamental physical quantities need an alternative description. We derive the word average value of interaction coupling constant α<sub>s</sub>(m<sub>z</sub>) from the observed maximum galactic rotation velocity by the simple relation , where is the velocity, at which the difference between galactic rotation velocity and Thomas precession is equal, and α is Sommerfeld’s constant. The result is in excellent agreement with the value of α<sub>s</sub> = 0.1170 ± 0.0019, recently measured and verified via QCE analysis by CERN researchers. One can formulate a reciprocity relation, connecting α<sub>s</sub> with the circle constant: . It is the merit of Preston Guynn to derive the Milky Way maximum value of the galactic rotation velocity β<sub>g</sub>, pointing to its “extremely important role in all physics”. The mass (energy) constituents of the Universe follow a golden mean hierarchy and can simply be related to the maximum of Guynn’s difference velocity respectively to α<sub>s</sub>(m<sub>z</sub>), therewith excellently confirming Bouchet’s WMAP data analysis. We conclude once more that the golden mean concept is the leading one of nature. 展开更多
关键词 Strong Coupling Constant Sommerfeld’ Constant Gravitational Coupling Constant galactic Velocity Structure-Matter Theory Reciprocity Relation Goldem Mean Hierarchy mass and Energy Constituents of the Universe Superconductivity Matter-Antimatter Asymmetry Unification of Science
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Phenomenology of colored radiative neutrino mass model and its implications on cosmic-ray observations
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作者 Ran Ding Zhi-Long Han +1 位作者 Li Huang Yi Liao 《Chinese Physics C》 SCIE CAS CSCD 2018年第10期1-18,共18页
We extend the colored Zee-Babu model with a gauged U(1)B-L symmetry, and a scalar singlet dark matter (DM) candidate S. The spontaneous breaking of U(1)B-L leaves a residual Z2 symmetry that stabilizes the DM, a... We extend the colored Zee-Babu model with a gauged U(1)B-L symmetry, and a scalar singlet dark matter (DM) candidate S. The spontaneous breaking of U(1)B-L leaves a residual Z2 symmetry that stabilizes the DM, and generates a tiny neutrino mass at the two-loop level with the color seesaw mechanism. After investigating the DM and flavor phenomenology of this model systematically, we further focus on its imprint on two cosmic-ray anomalies: The Fermi-LAT gamma-ray excess at the Galactic Center (GCE), and the PeV ultra-high energy (UHE) neutrino events at the IceCube. We found that the Fermi-LAT GCE spectrum can be well-fitted by DM annihilation into a pair of on-shell singlet Higgs mediators while being compatible with the constraints from the relic density, direct detections, and dwarf spheroidal galaxies, in the Milky Way. Although the UHE neutrino events at the IceCube could be accounted for by the resonance production of a TeV-scale leptoquark, the relevant Yukawa couplings have been severely limited by the current low-energy flavor experiments. We subsequently derive the IceCube limits on the Yukawa couplings by employing its latest six-year data. 展开更多
关键词 neutrino mass models gamma-ray excess at galactic center IceCube neutrinos dark matter
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利用Miller-Scalo初始质量函数计算银晕的化学演化
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作者 岑敏锐 《华中师范大学学报(自然科学版)》 CAS CSCD 北大核心 2001年第4期402-406,共5页
银晕是银河系的重要组成部分 ,本文利用 Miller-Scalo形式的初始质量函数并结合 TSY化学演化模型 ,通过拟合晕族恒星随金属丰度的计数的观测值 。
关键词 银晕 化学演化 初始质量函数 银河系 金属丰度 Miller-Scalo形式 恒星
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活动星系核的演化研究
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作者 鲍玉英 陈洛恩 李开毅 《云南师范大学学报(自然科学版)》 2013年第5期18-21,共4页
活动星系核的演化研究在能量产生、辐射机制等基本问题的研究中占有重要的地位。首先对活动星系核的基本性质及分类进行了简单的介绍,然后根据搜集到的数据,通过分析发光度、中心黑洞质量、吸积率与红移的关系图,进一步支持了活动星系... 活动星系核的演化研究在能量产生、辐射机制等基本问题的研究中占有重要的地位。首先对活动星系核的基本性质及分类进行了简单的介绍,然后根据搜集到的数据,通过分析发光度、中心黑洞质量、吸积率与红移的关系图,进一步支持了活动星系核的演化存在的两个演化序列的观点:一个是平谱射电类星体FSRQ逐步过渡到BL Lac天体,然后过渡到射电星系RG,最后过渡到椭圆星系;另一个是从类星体Quasars过渡Seyfert星系,然后过渡到正常漩涡星系。 展开更多
关键词 活动星系核 吸积率 中心黑洞质量 红移量 热光度
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银河系中探测第一代恒星的几率
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作者 岑敏锐 陆烨 赵刚 《天文学报》 CSCD 北大核心 2001年第2期155-160,共6页
第一代恒星是形成于宇宙大爆炸后的原始气体中的、不含重于碳元素的、寿命大于 1 4Gyr的、迄今尚未演化的最古老的恒星 .长期的观测结果表明银河系中尚未发现金属丰度 ([Fe/H] )为零、甚至金属丰度 [Fe/H]≤ - 6的恒星 .为解释这一观察... 第一代恒星是形成于宇宙大爆炸后的原始气体中的、不含重于碳元素的、寿命大于 1 4Gyr的、迄今尚未演化的最古老的恒星 .长期的观测结果表明银河系中尚未发现金属丰度 ([Fe/H] )为零、甚至金属丰度 [Fe/H]≤ - 6的恒星 .为解释这一观察现象 ,将以Tsuiimoto等人提出的银晕的化学演化模型为基础 ,假设形成第一代恒星的初始质量函数具有Miller Scalo的形式 ,从理论上预言和讨论探测第一代恒星的可能性 .利用已有的晕星的观测资料限定模型的参数 .如果形成恒星的云的质量为 1 0 6 M - 1 0 7M ,模型结果预言探测到第一代恒星的几率为 6 .1 4× 1 0 - 4 - 6 .1 4× 1 0 - 5 . 展开更多
关键词 银晕 化学演化模型 星族Ⅲ恒星 初始质量函数 银河系
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利用OⅥ与SiⅣ+OⅣ]发射线计算类星体黑洞质量
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作者 刘婉晴 商朝晖 《天津师范大学学报(自然科学版)》 CAS 2016年第4期13-20,共8页
为了详尽地揭示发射线的结构特征,基于含有85个类星体的样本,利用由空间和地面望远镜准同时观测获得的高质量光谱,通过"SPECFIT"程序拟合高电离远紫外发射线OⅥλ1033.82和SiⅣ+OⅣ]λλ1396.75,1402.34,实现对谱线的详细测量... 为了详尽地揭示发射线的结构特征,基于含有85个类星体的样本,利用由空间和地面望远镜准同时观测获得的高质量光谱,通过"SPECFIT"程序拟合高电离远紫外发射线OⅥλ1033.82和SiⅣ+OⅣ]λλ1396.75,1402.34,实现对谱线的详细测量.结合拟合结果和相关数据,给出基于OⅥ和SiⅣ+OⅣ]发射线的对类星体中心黑洞质量的计算公式,并将所得结果与他人研究结果进行比较,结果表明由OⅥ线所得黑洞质量的弥散小于由SiⅣ+OⅣ]线所得黑洞质量的弥散,说明利用OⅥ发射线计算黑洞质量结果较好,证明在估算高红移类星体的黑洞质量时,利用OⅥ线比SiⅣ+OⅣ]线更可行且合适. 展开更多
关键词 OⅥ与SiIV+OⅣ]发射线 活动星系核 高红移类星体 黑洞质量
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中等质量黑洞活动星系核的射电连续谱研究:总结与展望
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作者 董小波 毛羽丰 钱磊 《天文学进展》 CSCD 北大核心 2020年第2期155-167,共13页
中等质量黑洞活动星系核(intermediate mass black hole active galactic nuclei, IMBH AGN)是指中心黑洞大约在10~2M⊙~10~6M⊙质量范围的活动星系核。关于近邻宇宙中IMBH AGN的研究,对于理解高红移类星体中的超大质量黑洞起源(即"... 中等质量黑洞活动星系核(intermediate mass black hole active galactic nuclei, IMBH AGN)是指中心黑洞大约在10~2M⊙~10~6M⊙质量范围的活动星系核。关于近邻宇宙中IMBH AGN的研究,对于理解高红移类星体中的超大质量黑洞起源(即"种子黑洞问题")、低频引力波源等基本问题有着重要意义。得益于近20年来大规模光学光谱巡天的发展,已发现近邻宇宙中的宽线IMBH AGN的数目超过500个。对于这些光学选IMBH AGN,基于VLA FIRST巡天数据,针对小样本或个源的专门射电连续谱观测,已取得不少结果。从射电形态、连续谱谱型、射电功率和射电噪度、黑洞吸积基本面这四个方面,详细地介绍了目前IMBH AGN射电连续谱研究的进展。并且,分别面向当前正在开展的几个SKA探路者大规模连续谱巡天项目,以及大约10年后运行的SKA (至少是SKA一期),展望了IMBH AGN领域将来可以进行研究的科学目标。 展开更多
关键词 中等质量黑洞 种子黑洞 低光度活动星系核 黑洞吸积 相对论喷流
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