Schleicher, Dominik R. G.

[["dc.bibliographiccitation.firstpage","2181"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","2187"],["dc.bibliographiccitation.volume","441"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Grassi, T."],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.date.accessioned","2018-11-07T09:38:12Z"],["dc.date.available","2018-11-07T09:38:12Z"],["dc.date.issued","2014"],["dc.description.abstract","While Population III (Pop III) stars are typically thought to be massive, pathways towards lower mass Pop III stars may exist when the cooling of the gas is particularly enhanced. A possible route is enhanced HD cooling during the merging of dark-matter haloes. The mergers can lead to a high ionization degree catalysing the formation of HD molecules and may cool the gas down to the cosmic microwave background temperature. In this paper, we investigate the merging of mini-haloes with masses of a few 10(5) M-aS (TM) and explore the feasibility of this scenario. We have performed three-dimensional cosmological hydrodynamics calculations with the enzo code, solving the thermal and chemical evolution of the gas by employing the astrochemistry package krome. Our results show that the HD abundance is increased by two orders of magnitude compared to the no-merging case and the halo cools down to similar to 60 K triggering fragmentation. Based on Jeans estimates, the expected stellar masses are about 10 M-aS (TM). Our findings show that the merging scenario is a potential pathway for the formation of low-mass stars."],["dc.identifier.doi","10.1093/mnras/stu714"],["dc.identifier.isi","000338763600027"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33019"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","Dark-matter halo mergers as a fertile environment for low-mass Population III star formation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A22"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","572"],["dc.contributor.author","van Borm, C."],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Spaans, M."],["dc.contributor.author","Grassi, T."],["dc.date.accessioned","2018-11-07T09:31:57Z"],["dc.date.available","2018-11-07T09:31:57Z"],["dc.date.issued","2014"],["dc.description.abstract","Context. The seeds of the first supermassive black holes may have resulted from the direct collapse of hot primordial gas in greater than or similar to 10(4) K haloes, forming a supermassive or quasi- star as an intermediate stage. Aims. We explore the formation of a protostar resulting from the collapse of primordial gas in the presence of a strong Lyman- Werner radiation background. Particularly, we investigate the impact of turbulence and rotation on the fragmentation behaviour of the gas cloud. We accomplish this goal by varying the initial turbulent and rotational velocities. Methods. We performed 3D adaptive mesh refinement simulations with a resolution of 64 cells per Jeans length using the ENZO code, simulating the formation of a protostar up to unprecedentedly high central densities of 10(21) cm(-3) and spatial scales of a few solar radii. To achieve this goal, we employed the KROME package to improve modelling of the chemical and thermal processes. Results. We find that the physical properties of the simulated gas clouds become similar on small scales, irrespective of the initial amount of turbulence and rotation. After the highest level of refinement was reached, the simulations have been evolved for an additional similar to 5 freefall times. A single bound clump with a radius of 2 x 10(-2) AU and a mass of similar to 7 x 10(-2) M fi is formed at the end of each simulation, marking the onset of protostar formation. No strong fragmentation is observed by the end of the simulations, regardless of the initial amount of turbulence or rotation, and high accretion rates of a few solar masses per year are found. Conclusions. Given such high accretion rates, a quasi- star of 105 M fi is expected to form within 105 years."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [SFB 963 / 1]"],["dc.identifier.doi","10.1051/0004-6361/201424658"],["dc.identifier.fs","609689"],["dc.identifier.isi","000346101700037"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11406"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/31640"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","1432-0746"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Effects of turbulence and rotation on protostar formation as a precursor of massive black holes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2386"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","2419"],["dc.bibliographiccitation.volume","439"],["dc.contributor.author","Grassi, T."],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Prieto, Jose Luis"],["dc.contributor.author","Seifried, D."],["dc.contributor.author","Simoncini, E."],["dc.contributor.author","Gianturco, F. A."],["dc.date.accessioned","2018-11-07T09:41:46Z"],["dc.date.available","2018-11-07T09:41:46Z"],["dc.date.issued","2014"],["dc.description.abstract","Chemistry plays a key role in many astrophysical situations regulating the cooling and the thermal properties of the gas, which are relevant during gravitational collapse, the evolution of discs and the fragmentation process. In order to simplify the usage of chemical networks in large numerical simulations, we present the chemistry package krome, consisting of a python pre-processor which generates a subroutine for the solution of chemical networks which can be embedded in any numerical code. For the solution of the rate equations, we make use of the high-order solver DLSODES, which was shown to be both accurate and efficient for sparse networks, which are typical in astrophysical applications. krome also provides a large set of physical processes connected to chemistry, including photochemistry, cooling, heating, dust treatment and reverse kinetics. The package presented here already contains a network for primordial chemistry, a small metal network appropriate for the modelling of low metallicities environments, a detailed network for the modelling of molecular clouds, a network for planetary atmospheres, as well as a framework for the modelling of the dust grain population. In this paper, we present an extended test suite ranging from one-zone and 1D models to first applications including cosmological simulations with enzo and ramses and 3D collapse simulations with the flash code. The package presented here is publicly available at https://bitbucket.org/krome/krome_stable."],["dc.identifier.doi","10.1093/mnras/stu114"],["dc.identifier.isi","000334114900014"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33803"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","KROME - a package to embed chemistry in astrophysical simulations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3163"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","3177"],["dc.bibliographiccitation.volume","446"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Grassi, T."],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Spaans, M."],["dc.date.accessioned","2018-11-07T10:02:02Z"],["dc.date.available","2018-11-07T10:02:02Z"],["dc.date.issued","2015"],["dc.description.abstract","Observations of high-redshift quasars at z > 6 indicate that they harbour supermassive black holes (SMBHs) of a billion solar masses. The direct collapse scenario has emerged as the most plausible way to assemble SMBHs. The nurseries for the direct collapse black holes are massive primordial haloes illuminated with an intense UV flux emitted by Population II (Pop II) stars. In this study, we compute the critical value of such a flux (J(21)(crit)) for realistic spectra of Pop II stars through three-dimensional cosmological simulations. We derive the dependence of J(21)(crit) on the radiation spectra, on variations from halo to halo, and on the impact of X-ray ionization. Our findings show that the value of J(21)(crit) is a few times 10(4) and only weakly depends on the adopted radiation spectra in the range between T-rad = 2 x 10(4) and 10(5) K. For three simulated haloes of a few times 10(7) M-circle dot, J(21)(crit) varies from 2 x 10(4) to 5 x 10(4). The impact of X-ray ionization is almost negligible and within the expected scatter of J(21)(crit) for background fluxes of J(X, 21) <= 0.1. The computed estimates of J(21)(crit) have profound implications for the quasar abundance at z = 10 as it lowers the number density of black holes forming through an isothermal direct collapse by a few orders of magnitude below the observed black hole density. However, the sites with moderate amounts of H-2 cooling may still form massive objects sufficient to be compatible with observations."],["dc.identifier.doi","10.1093/mnras/stu2244"],["dc.identifier.isi","000350272300076"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38147"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","How realistic UV spectra and X-rays suppress the abundance of direct collapse black holes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","531"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Astronomische Nachrichten"],["dc.bibliographiccitation.lastpage","536"],["dc.bibliographiccitation.volume","334"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schober, Jennifer"],["dc.contributor.author","Schmidt, Wolfram"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Federrath, Christoph"],["dc.contributor.author","Niemeyer, J."],["dc.contributor.author","Banerjee, R."],["dc.contributor.author","Klessen, Ralf S."],["dc.date.accessioned","2018-11-07T09:22:39Z"],["dc.date.accessioned","2020-07-09T08:55:45Z"],["dc.date.available","2018-11-07T09:22:39Z"],["dc.date.available","2020-07-09T08:55:45Z"],["dc.date.issued","2013"],["dc.description.abstract","We explore the amplification of magnetic fields in the high-redshift Universe. For this purpose, we perform high-resolution cosmological simulations following the formation of primordial halos with \\sim10^7 M_solar, revealing the presence of turbulent structures and complex morphologies at resolutions of at least 32 cells per Jeans length. Employing a turbulence subgrid-scale model, we quantify the amount of unresolved turbulence and show that the resulting turbulent viscosity has a significant impact on the gas morphology, suppressing the formation of low-mass clumps. We further demonstrate that such turbulence implies the efficient amplification of magnetic fields via the small-scale dynamo. We discuss the properties of the dynamo in the kinematic and non-linear regime, and explore the resulting magnetic field amplification during primordial star formation. We show that field strengths of \\sim10^{-5} G can be expected at number densities of \\sim5 cm^{-3}."],["dc.identifier.doi","10.1002/asna.201211898"],["dc.identifier.isi","000325862900007"],["dc.identifier.scopus","2-s2.0-84879824861"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/66910"],["dc.identifier.url","http://www.scopus.com/inward/record.url?eid=2-s2.0-84879824861&partnerID=MN8TOARS"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.eissn","0004-6337"],["dc.relation.issn","1521-3994"],["dc.title","Magnetic fields during high redshift structure formation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A13"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","561"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Grassi, T."],["dc.date.accessioned","2018-11-07T09:46:39Z"],["dc.date.available","2018-11-07T09:46:39Z"],["dc.date.issued","2014"],["dc.description.abstract","Context. Population III stars are the first stars in the Universe to form at z = 20-30 out of a pure hydrogen and helium gas in minihalos of 10(5)-10(6) M-circle dot. Cooling and fragmentation is thus regulated via molecular hydrogen. At densities above 10(8) cm(-3), the three-body H-2 formation rates are particularly important for making the gas fully molecular. These rates were considered to be uncertain by at least a few orders of magnitude. Aims. We explore the impact of recently derived accurate three-body H-2 formation for three different minihalos, and compare them with the results obtained with three-body rates employed in previous other studies. Methods. The calculations were performed with the cosmological hydrodynamics code ENZO (release 2.2) coupled with the chemistry package KROME (including a network for primordial chemistry), which was previously shown to be accurate in high-resolution simulations. Results. While the new rates can shift the point where the gas becomes fully molecular, leading to a different thermal evolution, there is no trivial trend in the way this occurs. While one might naively expect the results to follow the rate coefficients trend, the behavior can vary depending on the dark-matter halo that is explored. Conclusions. We conclude that employing the correct three-body rates is about equally important as the use of appropriate initial conditions, and that the resulting thermal evolution needs to be calculated for every halo individually."],["dc.description.sponsorship","DFG [SCHL 1964/1-1]; CINECA consortium; [SFB 963/1]"],["dc.identifier.doi","10.1051/0004-6361/201322387"],["dc.identifier.fs","609680"],["dc.identifier.isi","000330584000013"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10884"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34928"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","1432-0746"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Primordial star formation: relative impact of H-2 three-body rates and initial conditions"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1979"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","1987"],["dc.bibliographiccitation.volume","443"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","van Borm, C."],["dc.contributor.author","Grassi, T."],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Spaans, M."],["dc.date.accessioned","2018-11-07T09:35:06Z"],["dc.date.available","2018-11-07T09:35:06Z"],["dc.date.issued","2014"],["dc.description.abstract","The ability of metal-free gas to cool by molecular hydrogen in primordial haloes is strongly associated with the strength of ultraviolet (UV) flux produced by the stellar populations in the first galaxies. Depending on the stellar spectrum, these UV photons can either dissociate H-2 molecules directly or indirectly by photodetachment of H- as the latter provides the main pathway for H2 formation in the early universe. In this study, we aim to determine the critical strength of the UV flux above which the formation of molecular hydrogen remains suppressed for a sample of five distinct haloes at z > 10 by employing a higher order chemical solver and a Jeans resolution of 32 cells. We presume that such flux is emitted by Pop II stars implying atmospheric temperatures of 104 K. We performed three-dimensional cosmological simulations and varied the strength of the UV flux below the Lyman limit in units of J(21). Our findings show that the value of J(21)(crit) varies from halo to halo and is sensitive to the local thermal conditions of the gas. For the simulated haloes, it varies from 400 to 700 with the exception of one halo where J(21)(crit) >= 1500. This has important implications for the formation of direct collapse black holes and their estimated population at z > 6. It reduces the number density of direct collapse black holes by almost three orders of magnitude compared to the previous estimates."],["dc.identifier.doi","10.1093/mnras/stu1230"],["dc.identifier.isi","000342920400011"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32320"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","A UV flux constraint on the formation of direct collapse black holes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","066412"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","PHYSICAL REVIEW E"],["dc.bibliographiccitation.volume","86"],["dc.contributor.author","Schober, Jennifer"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Klessen, Ralf S."],["dc.date.accessioned","2018-11-07T09:02:11Z"],["dc.date.available","2018-11-07T09:02:11Z"],["dc.date.issued","2012"],["dc.description.abstract","The present-day Universe is highly magnetized, even though the first magnetic seed fields were most probably extremely weak. To explain the growth of the magnetic field strength over many orders of magnitude, fast amplification processes need to operate. The most efficient mechanism known today is the small-scale dynamo, which converts turbulent kinetic energy into magnetic energy leading to an exponential growth of the magnetic field. The efficiency of the dynamo depends on the type of turbulence indicated by the slope of the turbulence spectrum v(l) proportional to l(I),where v(l) is the eddy velocity at a scale l. We explore turbulent spectra ranging from incompressible Kolmogorov turbulence with I = 1/3 to highly compressible Burgers turbulence with I = 1/2. In this work, we analyze the properties of the small-scale dynamo for low magnetic Prandtl numbers Pm, which denotes the ratio of the magnetic Reynolds number, Rm, to the hydrodynamical one, Re. We solve the Kazantsev equation, which describes the evolution of the small-scale magnetic field, using the WKB approximation. In the limit of low magnetic Prandtl numbers, the growth rate is proportional to Rm((1-I)/(1+I)). We furthermore discuss the critical magnetic Reynolds number Rm(crit), which is required for small-scale dynamo action. The value of Rm(crit) is roughly 100 for Kolmogorov turbulence and 2700 for Burgers. Furthermore, we discuss that Rm(crit) provides a stronger constraint in the limit of low Pm than it does for large Pm. We conclude that the small-scale dynamo can operate in the regime of low magnetic Prandtl numbers if the magnetic Reynolds number is large enough. Thus, the magnetic field amplification on small scales can take place in a broad range of physical environments and amplify week magnetic seed fields on short time scales. DOI: 10.1103/PhysRevE.86.066412"],["dc.identifier.doi","10.1103/PhysRevE.86.066412"],["dc.identifier.isi","000312838400007"],["dc.identifier.pmid","23368064"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24617"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physical Soc"],["dc.relation.issn","1539-3755"],["dc.title","Small-scale dynamo at low magnetic Prandtl numbers"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","013055"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.volume","15"],["dc.contributor.affiliation","Bovino, S;"],["dc.contributor.affiliation","Schleicher, D R G;"],["dc.contributor.affiliation","Schober, J;"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Schober, Jennifer"],["dc.date.accessioned","2018-11-07T09:29:02Z"],["dc.date.available","2018-11-07T09:29:02Z"],["dc.date.issued","2013"],["dc.date.updated","2022-02-10T06:47:23Z"],["dc.description.abstract","The small-scale dynamo provides a highly efficient mechanism for the conversion of turbulent into magnetic energy. In astrophysical environments, such turbulence often occurs at high Mach numbers, implying steep slopes in the turbulent spectra. It is thus a central question whether the small-scale dynamo can amplify magnetic fields in the interstellar or intergalactic media, where such Mach numbers occur. To address this long-standing issue, we employ the Kazantsev model for turbulent magnetic field amplification, systematically exploring the effect of different turbulent slopes, as expected for Kolmogorov, Burgers, the Larson laws and results derived from numerical simulations. With the framework employed here, we give the first solution encompassing the complete range of magnetic Prandtl numbers, including Pm << 1, Pm similar to 1 and Pm >> 1. We derive scaling laws of the growth rate as a function of hydrodynamic and magnetic Reynolds number for Pm similar to 1 and Pm >> 1 for all types of turbulence. A central result concerns the regime of Pm similar to 1, where the magnetic field amplification rate increases rapidly as a function of Pm. This phenomenon occurs for all types of turbulence we have explored. We further find that the dynamo growth rate can be decreased by a few orders of magnitude for turbulence spectra steeper than Kolmogorov. We calculate the critical magnetic Reynolds number Rm(c) for magnetic field amplification, which is highest for the Burgers case. As expected, our calculation shows a linear behaviour of the amplification rate close to the threshold proportional to (Rm - Rm(c)). On the basis of the Kazantsev model, we therefore expect the existence of the small-scale dynamo for a given value of Pm as long as the magnetic Reynolds number is above the critical threshold."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2013"],["dc.identifier.doi","10.1088/1367-2630/15/1/013055"],["dc.identifier.eissn","1367-2630"],["dc.identifier.fs","602614"],["dc.identifier.isi","000314341600002"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/8703"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/30926"],["dc.language.iso","en"],["dc.notes","PACS: 98.62.En Electric and magnetic fields\r\n\r\n95.30.Lz Hydrodynamics\r\n\r\n98.58.Ay Physical properties (abundances, electron density, magnetic fields, scintillation, scattering, kinematics, dynamics, turbulence, etc.)"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","IOP Publishing"],["dc.relation.issn","1367-2630"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights.uri","http://creativecommons.org/licenses/by/3.0/"],["dc.title","Turbulent magnetic field amplification from the smallest to the largest magnetic Prandtl numbers"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","L35"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","790"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Grassi, T."],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.date.accessioned","2018-11-07T09:37:12Z"],["dc.date.available","2018-11-07T09:37:12Z"],["dc.date.issued","2014"],["dc.description.abstract","Recent discoveries of carbon-enhanced metal-poor stars like SMSS J031300.36-670839.3 provide increasing observational insights into the formation conditions of the first second-generation stars in the universe, reflecting the chemical conditions after the first supernova explosion. Here, we present the first cosmological simulations with a detailed chemical network including primordial species as well as C, C+, O, O+, Si, Si+, and Si2+ following the formation of carbon-enhanced metal-poor stars. The presence of background UV flux delays the collapse from z = 21 to z = 15 and cool the gas down to the cosmic microwave background temperature for a metallicity of Z/Z(circle dot) = 10(-3). This can potentially lead to the formation of lower-mass stars. Overall, we find that the metals have a stronger effect on the collapse than the radiation, yielding a comparable thermal structure for large variations in the radiative background. We further find that radiative backgrounds are not able to delay the collapse for Z/Z(circle dot) = 10(-2) or a carbon abundance as in SMSS J031300.36-670839.3."],["dc.identifier.doi","10.1088/2041-8205/790/2/L35"],["dc.identifier.isi","000339897100021"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32783"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","2041-8213"],["dc.relation.issn","2041-8205"],["dc.title","FORMATION OF CARBON-ENHANCED METAL-POOR STARS IN THE PRESENCE OF FAR-ULTRAVIOLET RADIATION"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]