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强作用对奇异星观测效应的影响 总被引:1,自引:0,他引:1
奇异星是类似于中子星的曲奇异夸克物质组成的致密天体。本文研究了夸克这间的强作用对奇异星观测效应的影响。我们认为:(1)中子星转变为奇异星的行为是一种大的周期突变(glitch)现象,这种现象取决于夸克间的强作用;(2)强作用使高温奇异星的振动阻尼也有效,这可能是驱动超新星爆发的新机制;(3)强作用加强了高温情形下奇异星和中子星在转动上的差别,奇异星的最小周期比中子星的小。 相似文献
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为统一解释伽玛射线暴(简称伽玛暴)与暴后再活动,提出了一个新的伽玛暴中心引擎模型一“奇异星-NDAF”模型(NDAF:Neutrino Dominated Accretion Flow,中微子主导吸积流),并计算了奇异星周围NDAF的结构.与其他中心致密天体不同的是,奇异星会向吸积流反馈以中微子为载体的奇异化相变能量.不考虑NDAF与奇异星的摩擦,结果表明:奇异星周围NDAF的结构对吸积率非常敏感;当吸积率大于0.18 Mo.S-1时,“奇异星-NDAF”模型能统一解释伽玛暴与暴后再活动,这个范围大于无摩擦的“中子星-NDAF”模型能统一解释的范围;在统一解释的情形下, “奇异星-NDAF”模型湮灭总能量的分布非常宽阔,当吸积率大于0.3 M0.S--1时,湮灭总能量大于1051 erg;最后,当吸积率大于0.3 M0.S-1时,“奇异星-NDAF”模型的湮灭光度超过同等吸积率下“黑洞-NDAF”模型一个多量级,有利于解释某些光度极大的伽玛暴. 相似文献
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对Be/X射线双星LSI+65°010/2S0114+65连续四年(1992—1995年)的光学光谱观测发现,在1992年11月它的Ha发射线等值宽度在4天内从-0.43A增至-1.48A,增加了约3.5倍.此剧烈变化支持LSI+65°10的光学子星是一颗Be星而非超巨星的论点.我们的观测还发现,1994年9月它的Ha发射线轮廓呈明显的双峰结构,但与普通Be星中由于旋转气壳而形成的双峰不同,其红峰处于Ha理论波长附近,紫峰却紫移了7.2A.我们认为此双峰可能产生在LSI+65°010的不同HⅡ区中,即红峰产生于Be星周围的气壳内,而紫峰很可能产生于在轨道上快速运动的中子星周围的HⅡ区中,此观测可能提供了中子星周围存在HⅡ区的证据.同样,我们认为1992年11月4日观测到的Ha发射线红翼几乎不变,紫翼却大幅增加的现象也是由于中子星周围的HⅡ区造成的. 相似文献
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为解释Be/X射线双星波段联合观测结果,已发展了许多理论模型。在本文中简述这些Be/X射线双星理论模型的研究现状,包括枞两个正常的B型星组成的密近双星演化成为Be/X射线双星的演化模型,描述Be星气壳的物理模型,Be星和中子星的性质所决定的中子星吸积方式的吸积量及Be/X射线双星X射线源光变曲线的理论解释。 相似文献
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The conversion from neutron stars with different equation of states (EOSs) for neutron matter into strange stars with different EOSs for strange quark matter has been studied in a general relativistic numerical calculation in this paper. For hot neutron stars, their conversion may lead to great variations in their rotation periods, of which the magnitude would be greatly dependent upon the EOS for neutron matter, and of which the timescale would be greatly determined by the EOS for strange matter. This phenomenon appears as giant glitches, which might provide a probe of EOSs for both neutron matter and strange matter. But for cold neutron stars, their conversion may result in a population of gamma-ray bursts. 相似文献
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We study the conversion of a neutron star to a strange star as a possible energy source for gamma-ray bursts. We use different recent models for the equation of state of neutron star matter and strange quark matter. We show that the total amount of energy liberated in the conversion is in the range of &parl0;1-4&parr0;x1053 ergs (1 order of magnitude larger than previous estimates) and is in agreement with the energy required to power gamma-ray burst sources at cosmological distances. 相似文献
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A broad sample of computed realistic equations of state of superdense matter with a quark phase transition is used to construct a series of models of neutron stars with a strange quark core. The integral characteristics of the stellar configurations are obtained: gravitational mass, rest mass, radius, relativistic moment of inertia, and red shift from the star's surface, as well as the mass and radius of the quark core within the allowable range of values for the central pressure. The parameters of some of the characteristic configurations of the calculated series are also given and these are studied in detail. It is found that a new additional region of stability for neutron stars with strange quark cores may exist for some models of the equation of state. 相似文献
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Strange stars are compact objects similar to neutron stars composed of strange matter. This paper investigates the observational effects of the strong interaction between quarks. We believe: 1) that the conversion of a neutron star to a strange star is a large “period glitch” which is determined by the strong interaction; 2) that the strong interaction results in effective damping of oscillation of hot strange stars, which could be a new mechanism of driving supernova explosions; 3) that the strong interaction increases the difference in rotation between strange and neutron stars under high temperatures, making the minimum period for strange stars lower than that for neutron stars. 相似文献
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An extensive set of realistic equations of state for superdense matter with a quark phase transition is derived on the basis of the three equations of state for neutron matter and the eight variants of strange quark-gluon plasmas in the MIT quark bag model. The characteristics of the phase transitions are described and the calculated equations of state with a density jump are studied in detail. 相似文献
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B. Kmpfer 《Astronomische Nachrichten》1984,305(4):193-197
We derive an upper bound on neutron star masses by using model equations of state in the nuclear matter density region and the causality limited equation of state in the ultradense region. Supposing that the model equations of state describe neutron star matter at nuclear matter density correctly we find as bound 3.75 M⊙. For large fiducial densities one gets a maximum mass which is above a previous estimate. 相似文献
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《天文和天体物理学研究(英文版)》2015,(6)
Using a realistic equation of state(EOS) of strange quark matter, namely,the modified bag model, and considering the constraints on the parameters of EOS by the observational mass limit of neutron stars, we investigate the r-mode instability window of strange stars, and find the same result as in the brief study of Haskell,Degenaar and Ho in 2012 that these instability windows are not consistent with the spin frequency and temperature observations of neutron stars in low mass X-ray binaries. 相似文献
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We study quarkand strangequarkmatter in the contextof generalrelativity.For this purpose,we solve Einstein's field equations for quark and strange quark matter in spherical symmetric space-times. We analyze strange quark matter for the different equations of state (EOS) in the spherical symmetric space-times,thus we are able to obtain the space-time geometries of quark and strange quark matter. Also,we discuss the features of the obtained solutions. The obtained solutions are consistent with the results of Brookhaven Laboratory,i.e. the quark-gluon plasma has a vanishing shear (i.e. quark-gluon plasma is perfect). 相似文献
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利用扩展的Skyrme作用可从Hartree-Fock多体理论中给出一种新的状态方程。本文在这个状态方程的基础上研究了静态中子星的性质。对于SKM和SG2这两个较好的Skyrme相互作用模型计算得到中子星的最大质量分别为Mmax=1.7M。,Max=1.67M。,此外,本文还研究了中子星的其它性质,如引力红移、惯量矩等,计算结果与观测以及Glitch模型符合。最后还发现在这种状态方程下,中子星冷却仅能通过冷却速度相对较慢的修正的Urca过程来实现。为便于比较,文中还计算了AV14+TBF和Paris TBF这两种三体相互作用模型下的中子星的性质。 相似文献