scholarly journals First Structure Formation and the First Stars

2003 ◽  
pp. 250-260 ◽  
Author(s):  
Michael L. Norman ◽  
Tom Abel ◽  
Greg Bryan
Keyword(s):  
Structure Formation ◽  
First Stars

scholarly journals Early structure formation in quintessence models and its implications for cosmic reionization from first stars

2006 ◽  
Vol 373 (2) ◽  
pp. 869-878 ◽  
Author(s):  
U. Maio ◽  
K. Dolag ◽  
M. Meneghetti ◽  
L. Moscardini ◽  
N. Yoshida ◽  
...  
Keyword(s):  
Structure Formation ◽  
First Stars

scholarly journals Lessons on early structure formation from a mature galaxy cluster observed at cosmic noon

2020 ◽  
Vol 495 (2) ◽  
pp. 1700-1705
Author(s):  
Boyuan Liu ◽  
Anna T P Schauer ◽  
Volker Bromm
Keyword(s):  
Star Formation ◽  
Structure Formation ◽  
Hubble Space Telescope ◽  
Age Distribution ◽  
Rapid Evolution ◽  
Galaxy Cluster ◽  
Starburst Galaxies ◽  
Boson Mass ◽  
First Stars ◽  
Low Mass

ABSTRACT We demonstrate a new approach of indirectly constraining both early star and structure formation via mature galaxy clusters at cosmic noon (z ∼ 2), using the cluster XLSSC 122 as an example. With the standard Press Schechter formalism, we infer a rapid evolution of the star formation efficiency (the ratio of stellar to halo mass) from 10−4 to 0.01 during z ∼ 20−13, based on the age distribution of stars in post-starburst galaxies of XLSSC 122, measured by Hubble Space Telescope photometry assuming no dust extinction. Here, we consider all low-mass haloes, including minihaloes, that host the first stars and galaxies ($5\times 10^5\ \rm M_{\odot }\lesssim M_{\rm halo}\lesssim 10^{10}\ \rm M_{\odot }$). We also place new constraints on fuzzy dark matter models of ma ≲ 5 × 10−21 eV/c2 for the ultralight boson mass, from the abundance of galaxies with star formation at z ≳ 13 in XLSSC 122. Our exploratory results are consistent with existing constraints. More comprehensive results will be obtained if our approach is extended to a large sample of clusters or field post-starburst galaxies at cosmic noon, with improved modelling of halo and stellar populations.

scholarly journals Formation of the First Stars and Blackholes

2017 ◽  
Vol 12 (S333) ◽  
pp. 209-215
Author(s):  
Naoki Yoshida
Keyword(s):  
Structure Formation ◽  
First Generation ◽  
Gravitational Instability ◽  
Big Bang ◽  
Density Fluctuations ◽  
Galactic Halos ◽  
Theoretical Studies ◽  
Intermediate Mass ◽  
First Stars ◽  
Physical Conditions

AbstractCosmic reionization is thought to be initiated by the first generation of stars and blackholes. We review recent progress in theoretical studies of early structure formation. Cosmic structure formation is driven by gravitational instability of primeval density fluctuations left over from Big Bang. At early epochs, there are baryonic streaming motions with significant relative velocity with respect to dark matter. The formation of primordial gas clouds is typically delayed by the streaming motions, but then physical conditions for the so-called direct collapse blackhole formation are realized in proto-galactic halos. We present a promising model in which intermediate mass blackholes are formed as early as z = 30.

scholarly journals The Galactic interstellar medium: foregrounds and star formation

2017 ◽  
Vol 12 (S333) ◽  
pp. 138-145
Author(s):  
Marc-Antoine Miville-Deschênes
Keyword(s):  
Star Formation ◽  
Interstellar Medium ◽  
Structure Formation ◽  
Statistical Properties ◽  
Line Of Sight ◽  
First Stars ◽  
Atomic Gas ◽  
Multi Phase

AbstractThis review presents briefly two aspects of Galactic interstellar medium science that seem relevant for studying EoR. First, we give some statistical properties of the Galactic foreground emission in the diffuse regions of the sky. The properties of the emission observed in projection on the plane of the sky are then related to how matter is organised along the line of sight. The diffuse atomic gas is multi-phase, with dense filamentary structures occupying only about 1% of the volume but contributing to about 50% of the emission. The second part of the review presents aspect of structure formation in the Galactic interstellar medium that could be relevant for the subgrid physics used to model the formation of the first stars.

Social development of modern Russia: trends, risks, prospects

2018 ◽  
pp. 76-89
Author(s):  
E. M. Avraamova ◽  
V. N. Titov
Keyword(s):  
Middle Class ◽  
Social Development ◽  
Social Structure ◽  
Structure Formation ◽  
Resource Availability ◽  
Social Dynamics ◽  
Quantitative Estimation ◽  
Resource Potential ◽  
Institutional Conditions ◽  
Resource Characteristics

The analysis of present-time directions in the study of social development has allowed to identify the resource approach as the most productive one which enables to assess social dynamics through the range of resource characteristics of different population groups and abilities of the relevant groups to apply development resources in the current economic and institutional conditions. Basing on the sociological survey conducted by ISAP RANEPA, the quantitative estimation of material and social recourses of the population has been made; integral values of the resource potential have been calculated as well. The issues of social structure formation are analyzed through the aspect of resource availability; the barriers of Russian middle-class enlargement are defined.

Characteristics Of The Structure Formation Of Gypsum Binder Modified With Zinc Hydrosilicates

2020 ◽  
pp. 40-46
Keyword(s):  
Synergistic Effect ◽  
Physicochemical Properties ◽  
Structure Formation ◽  
Silicic Acid ◽  
Chemical Properties ◽  
Crystal Formation ◽  
Ability To Act ◽  
Chemical Factors ◽  
Sorption Characteristics

The authors' methodic for assessing the role of chemical and physic-chemical factors during the structure formation of gypsum stone is presented in the article. The methodic is also makes it possible to reveal the synergistic effect and to determine the ranges of variation of controls factors that ensure maximum values of such effect. The effect of a micro-sized modifier based on zinc hydro-silicates on the structure formation of building gypsum is analyzed and corresponding dependencies are found. It is shown that effects of influence of modifier on the properties of gypsum compositions are determined by chemical properties of modifier. Among the mentioned properties are sorption characteristics (which depend on the amount of silicic acid and its state) and physicochemical properties - the ability to act as a substrate during crystal formation. The proposed method can also be extended to other binding substances and materials. This article contributes to the understanding of the processes that occur during the structure formation of composites, which will make it possible to control the structure formation in the future, obtaining materials with a given set of properties.

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