THE PROPERTIES OF STRANGE STARS IN THE QUARK MASS– DENSITY–DEPENDENT MODEL
THE PROPERTIES OF STRANGE STARS IN THE QUARK MASS– DENSITY–DEPENDENT MODEL
复制标题
DOI：
10.1142/s0218271898000048
复制
发表时间：
1998-02
影响因子：
2.2
通讯作者：
O. Benvenuto;G. Lugones
中科院分区：
文献类型：
--
作者：
O. Benvenuto;G. Lugones
在一个新的状态方程的框架下，我们研究了由奇异物质组成的致密物体的一般性质，其中夸克质量被参数化为重子密度的函数，使得它们在低(高)密度下是重(轻)的。这被称为“夸克质量密度相关模型”。在这个近似下，奇异物质的物态方程与麻省理工学院的袋子模型非常相似，但在低密度时要坚硬得多。这样的性质以相当大的方式改变了奇怪恒星的结构。在这个框架下，我们计算了奇异星的结构(质量、半径、中心密度、引力红移、转动惯量和总重子数)，发现结果与MIT袋模型中得到的结构非常相似，尽管出现了一些重要的差异。与标准的袋装天体(袋常数在B=60-80 MeV fm-3范围内)相比，我们发现这些天体可能比袋装天体质量更大，引力红移可能更大(最高可达≈10%)。转动惯量和总重子数可能比袋装情况下的大三倍。我们还计算了这些天体的前三个径向脉动模，发现周期与引力红移的关系与袋情况非常相似。此外，我们还给出了低质量奇异星区域中这种模式的解析处理，这与数值结果是合理一致的。
We study the general properties of compact objects made up of strange matter in the framework of a new equation of state in which the quark masses are parametrized as functions of the baryon density, so that they are heavy (light) at low (high) densities. This has been called the "quark mass-density-dependent model." In this approximation, the strange matter equation of state is rather similar to the corresponding to the MIT Bag Model, but it is significantly stiffer at low densities. Such a property modifies the structure of strange stars in a sizeable way. In this framework, we calculate the structure of strange stars (mass, radius, central density, gravitational redshift, moment of inertia, and total baryon number) finding that the resulting structures are rather similar to those obtained in the MIT Bag model, although some important differences appear. Comparing to the standard bagged case (with a bag constant in the range of B = 60 - 80 MeV fm-3), we find that these objects may be more massive and may show gravitational redshifts larger (up to ≈ 10%) than in the bag case. The moment of inertia and total baryon number may be larger than in the bagged case up to a factor of three. We also calculate the first three radial pulsation modes of these objects, finding that the relation of period vs. gravitational redshift is rather similar to the bag case. Also, we present an analytical treatment for such modes in the low-mass strange stars regime, which is in reasonable agreement with the numerical results.