Abstract <p>The paper analyzes formation conditions for globular clusters (GCs) in circumgalactic clouds. The similarity between the metallicity distributions of GCs in the nearby Universe and of circumgalactic clouds is substantiated in detail over a wide range of redshifts: from 0.2 to 5.9. The distributions of the number of circumgalactic clouds and GCs both contain a sequence of four local maxima at the metallicity values: <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\([\textrm{X/H}]\simeq-2.6,-2.0,-1.4,-0.5\)</EquationSource> <!--ASPBull2660005Acharova-m1--> </InlineEquation>. The sequential enrichment of a circumgalactic cloud with a mass of <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(10^{8}\,M_{\odot}\)</EquationSource> <!--ASPBull2660005Acharova-m2--> </InlineEquation> is calculated starting the extremely low metallicity <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\([\textrm{X/H}]&lt;-2.3\)</EquationSource> <!--ASPBull2660005Acharova-m3--> </InlineEquation>, then following through the stages of <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(-2.3\leq[\textrm{X/H}]&lt;-1.7\)</EquationSource> <!--ASPBull2660005Acharova-m4--> </InlineEquation> and <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(-1.7\leq[\textrm{X/H}]&lt;-0.9\)</EquationSource> <!--ASPBull2660005Acharova-m5--> </InlineEquation> to the high metallicity <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\([\textrm{X/H}]\geq-0.9\)</EquationSource> <!--ASPBull2660005Acharova-m6--> </InlineEquation>, where the boundaries of these ranges coincide with the local minima of the number of objects in the distributions. It is shown that for the reproduction of such distributions, it is sufficient that at each stage of enrichment of a part of a cloud in metals, one or more GCs with a total mass of <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(3\times 10^{6}\,M_{\odot}\)</EquationSource> <!--ASPBull2660005Acharova-m7--> </InlineEquation> are formed. It is shown that the maximum mass of stars capable of leading to supernova explosions increases with the increase of metallicity. Possible values of this mass are calculated for the metallicities corresponding to the maxima in the distributions of clouds and GCs.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Indicatives of Early Stages of Star Formation in the Universe

  • I. A. Acharova,
  • M. E. Sharina

摘要

Abstract

The paper analyzes formation conditions for globular clusters (GCs) in circumgalactic clouds. The similarity between the metallicity distributions of GCs in the nearby Universe and of circumgalactic clouds is substantiated in detail over a wide range of redshifts: from 0.2 to 5.9. The distributions of the number of circumgalactic clouds and GCs both contain a sequence of four local maxima at the metallicity values: \([\textrm{X/H}]\simeq-2.6,-2.0,-1.4,-0.5\) . The sequential enrichment of a circumgalactic cloud with a mass of \(10^{8}\,M_{\odot}\) is calculated starting the extremely low metallicity \([\textrm{X/H}]<-2.3\) , then following through the stages of \(-2.3\leq[\textrm{X/H}]<-1.7\) and \(-1.7\leq[\textrm{X/H}]<-0.9\) to the high metallicity \([\textrm{X/H}]\geq-0.9\) , where the boundaries of these ranges coincide with the local minima of the number of objects in the distributions. It is shown that for the reproduction of such distributions, it is sufficient that at each stage of enrichment of a part of a cloud in metals, one or more GCs with a total mass of \(3\times 10^{6}\,M_{\odot}\) are formed. It is shown that the maximum mass of stars capable of leading to supernova explosions increases with the increase of metallicity. Possible values of this mass are calculated for the metallicities corresponding to the maxima in the distributions of clouds and GCs.