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DC Field | Value | Language |
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dc.citation.endPage | 121 | - |
dc.citation.number | 2 | - |
dc.citation.startPage | 111 | - |
dc.citation.title | JOURNAL OF THE KOREAN ASTRONOMICAL SOCIETY | - |
dc.citation.volume | 333 | - |
dc.contributor.author | Kang, Hyesung | - |
dc.contributor.author | Lake, George | - |
dc.contributor.author | Ryu, Dongsu | - |
dc.date.accessioned | 2023-12-22T12:06:42Z | - |
dc.date.available | 2023-12-22T12:06:42Z | - |
dc.date.created | 2015-08-28 | - |
dc.date.issued | 2000-10 | - |
dc.description.abstract | Many models of globular cluster formation assume the presence of cold dense clouds in early universe. Here we re-examine the Fall & Rees (1985) model for formation of proto-globular cluster clouds (PGCCs) via thermal instabilities in a protogalactic halo. We first argue, based on the previous study of two-dimensional numerical simulations of thermally unstable clouds in a stratified halo of galaxy clusters by Real et al. (1991), that under the protogalactic environments only nonlinear (${\delta}{\ge}1$ 수식 이미지) density inhomogeneities can condense into PGCCs without being disrupted by the buoyancy-driven dynamical instabilities. We then carry out numerical simulations of the collapse of overdense douds in one-dimensional spherical geometry, including self-gravity and radiative cooling down to T = $10^4$ 수식 이미지 K. Since imprinting of Jeans mass at $10^4$ 수식 이미지 K is essential to this model, here we focus on the cases where external UV background radiation prevents the formation of $H_2$ 수식 이미지 molecules and so prevent the cloud from cooling below $10^4$ 수식 이미지 K. The quantitative results from these simulations can be summarized as follows: 1) Perturbations smaller than $M_{min}\~(10^{5.6}\;M{\bigodot})(nh/0.05cm^{-3})^{-2}$ 수식 이미지 cool isobarically, where nh is the unperturbed halo density, while perturbations larger than $M_{min}\~(10^8\;M{\bigodot})(nh/0.05cm^{-3})^{-2}$ 수식 이미지 cool isochorically and thermal instabilities do not operate. On the other hand, intermediate size perturbations ($M_{min} < M_{pgcc} < M_{max}$) are compressed supersonically, accompanied by strong accretion shocks. 2) For supersonically collapsing clouds, the density compression factor after they cool to $T_c = 10^4$ 수식 이미지 K range $10^{2.5} - 10^6$ 수식 이미지, while the isobaric compression factor is only $10^{2.5}$ 수식 이미지. 3) Isobarically collapsed clouds ($M < M_{min}$) are too small to be gravitationally bound. For supersonically collapsing clouds, however, the Jeans mass can be reduced to as small as $10^{5.5}\;M_{\bigodot}(nh/0.05cm^{-3})^{-1/2}$ 수식 이미지 at the maximum compression owing to the increased density compression. 4) The density profile of simulated PGCCs can be approximated by a constant core with a halo of $p{\infty} r^{-2}$ 수식 이미지 rather than a singular isothermal sphere. | - |
dc.identifier.bibliographicCitation | JOURNAL OF THE KOREAN ASTRONOMICAL SOCIETY, v.333, no.2, pp.111 - 121 | - |
dc.identifier.issn | 1225-4614 | - |
dc.identifier.uri | https://scholarworks.unist.ac.kr/handle/201301/16388 | - |
dc.identifier.url | http://ocean.kisti.re.kr/IS_mvpopo213L.do?ResultTotalCNT=7&pageNo=1&pageSize=10&method=view&acnCn1=&poid=kastros&kojic=CMHHBA&sVnc=v33n2&id=4&setId=64533&iTableId=4&iDocId=322810&sFree=%3D | - |
dc.language | 영어 | - |
dc.publisher | KOREAN ASTRONOMICAL SOCIETY | - |
dc.title | FORMATION OF PROTO-GLOBULAR CLUSTER CLOUDS BY THERMAL INSTABILITY | - |
dc.type | Article | - |
dc.description.journalRegisteredClass | scie | - |
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