Explosions in the early universe
Explosions in the early universe
复制标题
早期宇宙的爆炸
DOI：
10.1086/163079
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
E. Bertschinger
中科院分区：
文献类型：
--
作者：
E. Vishniac;J. Ostriker;E. Bertschinger
我们已经构建了一系列在不受干扰的宇宙中球对称爆炸的模拟。数值流体力学代码包括由于电子电导率、辐射冷却重力、离子粘度以及电子和离子温度之间的差异而产生的影响。爆炸的初始红移在50到2之间变化。爆炸的初始能量范围为10/sup 59/ ergs至10/sup 61/ ergs，与类星体或原始星系的能量输入相当。我们根据与星系间介质的可观测效应最明显相关的量来讨论这些爆炸的演化，包括它们的大小、总热能和动能、壳层温度和密度，以及作为时代函数的平均内部压力。在所有情况下，大部分经过激波的物质最终都被卷入相对致密的壳中。对于某些时期和能量范围，非径向不稳定性可能发生，要么是瑞利-泰勒型，要么是金斯型，导致致密碎片的形成。前一种不稳定性与低能事件更相关，并可能产生Ly. cap . α。在大能量事件的吸收中看到的云，产生受引力不稳定性影响的大质量壳，并可能产生束缚恒星系统。大多数模拟是在当前总物质密度等于临界密度的10%的情况下进行的。在这种情况下，最终（电流）和10/sup 61/ erg爆炸的半径和特殊速度为4.26 Mpc和19.2 km s/sup -1/，初始红移为10；3.64 Mpc和10.2 km s/sup -1/，初始红移为20。«少
We have constructed a series of simulations of spherically symmetric explosions in an otherwise unperturbed cosmology. The numerical hydrodynamics code includes effects due to electron conductivity, radiative cooling gravity, ion viscosity, and the difference between the electron and ion temperatures. The initial redshift of the explosions has been varied between a redshift of 50 and a redshift of 2. The initial energies of the explosions range from 10/sup 59/ ergs to 10/sup 61/ ergs, appropriate to the energy input from quasars or primeval galaxies. We discuss the evolution of these explosions in terms of the quantities most clearly related to observable effects on the intergalactic medium, including their size, total thermal and kinetic energies, shell temperatures and densities, and mean interior pressure as a function of epoch. In all cases most of the matter passed by the shock is eventually swept up into relatively dense shells. For certain epochs and ranges of energy, nonradial instabilities can occur, of either the Rayleigh-Taylor or the Jeans type, leading to the formation of dense fragments. The former instability is more relevant to low-energy events and may produce the Ly..cap alpha.. clouds seen in absorption with large-energy events producing massive shells subject to gravitationalmore » instabilities and possibly the production of bound stellar systems. Most of the simulations were run with the present total matter density equal to 10% of the critical density. For this case final (current) and radii and peculiar velocities of 10/sup 61/-erg explosions are 4.26 Mpc and 19.2 km s/sup -1/, for an initial redshift of 10, and 3.64 Mpc and 10.2 km s/sup -1/, for an initial redshift of 20.« less