Now showing 1 - 10 of 11
  • 2014Journal Article
    [["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"]]
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  • 2014Journal Article
    [["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"]]
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  • 2015Journal Article
    [["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"]]
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  • 2013Journal Article
    [["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"]]
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  • 2014Journal Article
    [["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"]]
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  • 2012Journal Article
    [["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"]]
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  • 2014Journal Article
    [["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"]]
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  • 2015Journal Article
    [["dc.bibliographiccitation.artnumber","023010"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","PHYSICAL REVIEW E"],["dc.bibliographiccitation.volume","92"],["dc.contributor.author","Schober, Jennifer"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Federrath, Christoph"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Klessen, Ralf S."],["dc.date.accessioned","2018-11-07T09:53:22Z"],["dc.date.available","2018-11-07T09:53:22Z"],["dc.date.issued","2015"],["dc.description.abstract","The origin of strong magnetic fields in the Universe can be explained by amplifying weak seed fields via turbulent motions on small spatial scales and subsequently transporting the magnetic energy to larger scales. This process is known as the turbulent dynamo and depends on the properties of turbulence, i.e., on the hydrodynamical Reynolds number and the compressibility of the gas, and on the magnetic diffusivity. While we know the growth rate of the magnetic energy in the linear regime, the saturation level, i.e., the ratio of magnetic energy to turbulent kinetic energy that can be reached, is not known from analytical calculations. In this paper we present a scale-dependent saturation model based on an effective turbulent resistivity which is determined by the turnover time scale of turbulent eddies and the magnetic energy density. The magnetic resistivity increases compared to the Spitzer value and the effective scale on which the magnetic energy spectrum is at its maximum moves to larger spatial scales. This process ends when the peak reaches a characteristic wave number k(star) which is determined by the critical magnetic Reynolds number. The saturation level of the dynamo also depends on the type of turbulence and differs for the limits of large and small magnetic Prandtl numbers Pm. With our model we find saturation levels between 43.8% and 1.3% for Pm >> 1 and between 2.43% and 0.135% for Pm << 1, where the higher values refer to incompressible turbulence and the lower ones to highly compressible turbulence."],["dc.identifier.doi","10.1103/PhysRevE.92.023010"],["dc.identifier.isi","000359054400007"],["dc.identifier.pmid","26382506"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36317"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physical Soc"],["dc.relation.issn","1550-2376"],["dc.relation.issn","1539-3755"],["dc.title","Saturation of the turbulent dynamo"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2013Journal Article
    [["dc.bibliographiccitation.firstpage","L36"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","L40"],["dc.bibliographiccitation.volume","434"],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Grassi, T."],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.date.accessioned","2018-11-07T09:20:21Z"],["dc.date.available","2018-11-07T09:20:21Z"],["dc.date.issued","2013"],["dc.description.abstract","The formation of the first stars in the Universe is regulated by a sensitive interplay of chemistry and cooling with the dynamics of a self-gravitating system. As the outcome of the collapse and the final stellar masses depend sensitively on the thermal evolution, it is necessary to accurately model the thermal evolution in high-resolution simulations. As previous investigations raised doubts regarding the convergence of the temperature at high resolution, we investigate the role of the numerical method employed to model the chemistry and the thermodynamics. Here we compare the standard implementation in the adaptive-mesh refinement code ENZO, employing a first-order backward differentiation formula (BDF), with the fifth-order accurate BDF solver DLSODES. While the standard implementation in ENZO shows a strong dependence on the employed resolution, the results obtained with DLSODES are considerably more robust, both with respect to the chemistry and thermodynamics, but also for dynamical quantities such as density, total energy or the accretion rate. We conclude that an accurate modelling of the chemistry and thermodynamics is central for primordial star formation."],["dc.identifier.doi","10.1093/mnrasl/slt072"],["dc.identifier.isi","000326875900008"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28861"],["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","Impact of an accurate modelling of primordial chemistry in high-resolution studies"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2014Journal Article
    [["dc.bibliographiccitation.artnumber","78"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","792"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Bovino, Stefano"],["dc.contributor.author","Grassi, T."],["dc.contributor.author","Spaans, M."],["dc.date.accessioned","2018-11-07T09:36:05Z"],["dc.date.available","2018-11-07T09:36:05Z"],["dc.date.issued","2014"],["dc.description.abstract","Radiative feedback produced by stellar populations played a vital role in early structure formation. In particular, photons below the Lyman limit can escape the star-forming regions and produce a background ultraviolet (UV) flux, which consequently may influence the pristine halos far away from the radiation sources. These photons can quench the formation of molecular hydrogen by photodetachment of H-. In this study, we explore the impact of such UV radiation on fragmentation in massive primordial halos of a few times 10(7) M-circle dot. To accomplish this goal, we perform high resolution cosmological simulations for two distinct halos and vary the strength of the impinging background UV field in units of J(21) assuming a blackbody radiation spectrum with a characteristic temperature of T-rad = 10(4) K. We further make use of sink particles to follow the evolution for 10,000 yr after reaching the maximum refinement level. No vigorous fragmentation is observed in UV-illuminated halos while the accretion rate changes according to the thermal properties. Our findings show that a few 10(2)-10(4) solar mass protostars are formed when halos are irradiated by J(21) = 10-500 at z > 10 and suggest a strong relation between the strength of the UV flux and mass of a protostar. This mode of star formation is quite different from minihalos, as higher accretion rates of about 0.01-0.1 M-circle dot yr(-1) are observed by the end of our simulations. The resulting massive stars are potential cradles for the formation of intermediate-mass black holes at earlier cosmic times and contribute to the formation of a global X-ray background."],["dc.identifier.doi","10.1088/0004-637X/792/1/78"],["dc.identifier.isi","000341172100078"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32532"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","1538-4357"],["dc.relation.issn","0004-637X"],["dc.title","THE FORMATION OF MASSIVE PRIMORDIAL STARS IN THE PRESENCE OF MODERATE UV BACKGROUNDS"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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