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.artnumber","L3"],["dc.bibliographiccitation.firstpage","L3"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","772"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Schmidt, W."],["dc.contributor.author","Niemeyer, J."],["dc.date.accessioned","2018-11-07T09:22:19Z"],["dc.date.accessioned","2020-07-21T06:05:19Z"],["dc.date.available","2018-11-07T09:22:19Z"],["dc.date.available","2020-07-21T06:05:19Z"],["dc.date.issued","2013"],["dc.description.abstract","Population III stars forming in the infant universe at z = 30 heralded the end of the cosmic dark ages. They are presumed to be assembled in the so-called minihalos with virial temperatures of a few thousand K where collapse is triggered by molecular hydrogen cooling. A central question concerns their final masses, and whether fragmentation occurs during their formation. While studies employing Lagrangian codes suggest fragmentation via a self-gravitating disk, recent high-resolution simulations indicated that disk formation is suppressed. Here we report the first high-resolution large-eddy simulations performed with the Eulerian grid-based code Enzo following the evolution beyond the formation of the first peak to investigate the accretion of the central massive clump and potential fragmentation. For a total of three halos, we see that a disk forms around the first clump. The central clump reaches similar to 10 solar masses after 40 yr, while subsequent accretion is expected at a rate of 10(-2) solar masses per year. In one of these halos, additional clumps form as a result of fragmentation which proceeds at larger scales. We note that subgrid-scale (SGS) turbulence yields relevant contributions to the stability of the protostellar disks. Both with and without the SGS model, the disk evolution appears rather stable during the timescale considered here. We conclude that the first protostar may reach masses up to 40-100 M-circle dot, which are only limited by the effect of radiative feedback."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [SFB 963/1, A12]; HLRN [nip00029]"],["dc.identifier.doi","10.1088/2041-8205/772/1/L3"],["dc.identifier.isi","000321696500003"],["dc.identifier.scopus","2-s2.0-84880624699"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29315"],["dc.identifier.url","http://www.scopus.com/inward/record.url?eid=2-s2.0-84880624699&partnerID=MN8TOARS"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.eissn","2041-8213"],["dc.relation.issn","2041-8205"],["dc.title","The formation of massive population III stars in the presence of turbulence"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","77"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","87"],["dc.bibliographiccitation.volume","449"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.date.accessioned","2018-11-07T09:57:35Z"],["dc.date.available","2018-11-07T09:57:35Z"],["dc.date.issued","2015"],["dc.description.abstract","Our understanding of Population III star formation is still in its infancy. They are formed in dark matter minihaloes of 10(5)-10(6) M-circle dot at z = 20-30. Recent high-resolution cosmological simulations show that a protostellar disc forms as a consequence of gravitational collapse and fragments into multiple clumps. However, it is not entirely clear if these clumps will be able to survive to form multiple stars as simulations are unable to follow the disc evolution for longer times. In this study, we employ a simple analytical model to derive the properties of marginally stable steady-state discs. Our results show that the stability of the disc depends on the critical value of the viscous parameter alpha. For alpha(crit) = 1, the disc is stable for an accretion rate of <= 10(-3) M-circle dot yr(-1) and becomes unstable at radii about >= 100 au in the presence of an accretion rate of 10(-2) M-circle dot yr(-1). For 0.06 < alpha(crit) < 1, the disc can be unstable for both accretion rates. The comparison of the migration and the Kelvin-Helmholtz time-scales shows that clumps are expected to migrate inwards before reaching the main sequence. Furthermore, in the presence of a massive central star, the clumps within the central 1 au will be tidally disrupted. We also find that UV feedback from the central star is unable to disrupt the disc, and that photoevaporation becomes important only once the accretion rate has dropped to 2 x 10(-4) M-circle dot yr(-1). As a result, the central star may reach a mass of 100 M-circle dot or even higher."],["dc.description.sponsorship","European Research Council under the European Community [614199]"],["dc.identifier.doi","10.1093/mnras/stu2573"],["dc.identifier.isi","000355345600007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37194"],["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","Disc fragmentation and the formation of Population III stars"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2989"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","2996"],["dc.bibliographiccitation.volume","436"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Schmidt, Wolfram"],["dc.contributor.author","Niemeyer, J. C."],["dc.date.accessioned","2018-11-07T09:17:04Z"],["dc.date.accessioned","2020-07-09T08:43:58Z"],["dc.date.available","2018-11-07T09:17:04Z"],["dc.date.available","2020-07-09T08:43:58Z"],["dc.date.issued","2013"],["dc.description.abstract","Black holes of a billion solar masses are observed in the infant universe a few hundred million years after the Big Bang. The direct collapse of protogalactic gas clouds in primordial halos with $\\rm T_{vir} \\geq 10^{4} K$ provides the most promising way to assemble massive black holes. In this study, we aim to determine the characteristic mass scale of seed black holes and the time evolution of the accretion rates resulting from the direct collapse model. We explore the formation of supermassive black holes via cosmological large eddy simulations (LES) by employing sink particles and following their evolution for twenty thousand years after the formation of the first sink. As the resulting protostars were shown to have cool atmospheres in the presence of strong accretion, we assume here that UV feedback is negligible during this calculation. We confirm this result in a comparison run without sinks. Our findings show that black hole seeds with characteristic mass of $\\rm 10^{5} M_{\\odot}$ are formed in the presence of strong Lyman Werner flux which leads to an isothermal collapse. The characteristic mass is a about two times higher in LES compared to the implicit large eddy simulations (ILES). The accretion rates increase with time and reach a maximum value of 10 $\\rm M_{\\odot}/yr$ after $\\rm 10^{4}$ years. Our results show that the direct collapse model is clearly feasible as it provides the expected mass of the seed black holes."],["dc.identifier.doi","10.1093/mnras/stt1786"],["dc.identifier.isi","000327798100009"],["dc.identifier.scopus","2-s2.0-84889036204"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/66907"],["dc.identifier.url","http://www.scopus.com/inward/record.url?eid=2-s2.0-84889036204&partnerID=MN8TOARS"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.eissn","0035-8711"],["dc.relation.issn","1365-2966"],["dc.title","The characteristic black hole mass resulting from direct collapse in the early Universe"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["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","A101"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","540"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Spaans, M."],["dc.date.accessioned","2018-11-07T09:11:27Z"],["dc.date.available","2018-11-07T09:11:27Z"],["dc.date.issued","2012"],["dc.description.abstract","Numerical simulations suggest that the first galaxies are formed in protogalactic halos with virial temperatures >= 10(4) K. It is likely that such halos are polluted with trace amounts of metals produced by the first generation of stars. The presence of dust can significantly change the chemistry and dynamics of early galaxies. In this article, we aim to assess the role of dust on the thermal and dynamical evolution of the first galaxies in the presence of a background UV flux, and its implications for the observability of Lyman-alpha emitters and sub-mm sources. We have performed high resolution cosmological simulations using the adaptive mesh refinement code FLASH to accomplish this goal. We have developed a chemical network appropriate for these conditions and coupled it with the FLASH code. The main ingredients of our chemical model include the formation of molecules (both in the gas phase and on dust grains), a multi-level treatment of atomic hydrogen, line trapping of Ly-alpha photons and, photoionization and photodissociation processes in a UV background. We found that the formation of molecules (H-2 and HD) is significantly enhanced in the presence of dust grains as compared to only gas phase reactions by up to two orders of magnitude. The presence of dust may thus establish a molecular ISM in high-redshift galaxies. The presence of a background UV flux strongly influences the formation of molecules by photodissociating them. We explore the evolution after a major merger, leading to the formation of a binary disk. These disks have gas masses of similar to 10(7) M-circle dot at a redshift of 5.4. Each disk lies in a separate subhalo as a result of the merger event. The disks are supported by turbulent pressure due to the highly supersonic turbulence present in the halo. For values of J(21) = 1000 (internal flux), we find that fragmentation may be enhanced due to thermal instabilities in the hot gas. The presence of dust does not significantly reduce the Ly-alpha emission. The emission of Ly-alpha is extended and originates from the envelope of the halo due to line trapping effects. We also find that dust masses of a few x10(8) M-circle dot are required to observe the dust continuum emission from z similar to 5 galaxies with ALMA."],["dc.identifier.doi","10.1051/0004-6361/201118295"],["dc.identifier.fs","596713"],["dc.identifier.isi","000303315400115"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9598"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26725"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","The implications of dust for high-redshift protogalaxies and the formation of binary disks"],["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","2969"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","2975"],["dc.bibliographiccitation.volume","440"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Niemeyer, J. C."],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.date.accessioned","2018-11-07T09:39:45Z"],["dc.date.accessioned","2020-07-02T07:47:30Z"],["dc.date.available","2018-11-07T09:39:45Z"],["dc.date.available","2020-07-02T07:47:30Z"],["dc.date.issued","2013"],["dc.description.abstract","Baryonic streaming motions produced prior to the epoch of recombination became supersonic during the cosmic dark ages. Various studies suggest that such streaming velocities change the halo statistics and also influence the formation of Population III stars. In this study, we aim to explore the impact of streaming velocities on the formation of supermassive black holes at $z>10$ via the direct collapse scenario. To accomplish this goal, we perform cosmological large eddy simulations for two halos of a few times $\\rm 10^{7} M_{\\odot}$ with initial streaming velocities of 3, 6 and 9 $\\rm km/s$. These massive primordial halos illuminated by the strong Lyman Werner flux are the potential cradles for the formation of direct collapse seed black holes. To study the evolution for longer times, we employ sink particles and track the accretion for 10,000 years. Our findings show that higher streaming velocities increase the circular velocities from about 14 $\\rm km/s$ to 16 $\\rm km/s$. They also delay the collapse of halos for a few million years, but do not have any significant impact on the halo properties such as turbulent energy, radial velocity, density and accretion rates. Sink particles of about $\\rm \\sim 10^5 M_{\\odot}$ are formed at the end of our simulations and no clear distribution of sink masses is observed in the presence of streaming motions. It is further found that the impact of streaming velocities is less severe in massive halos compared to the minihalos as reported in the previous studies."],["dc.identifier.doi","10.1093/mnras/stu489"],["dc.identifier.isi","000336213800007"],["dc.identifier.scopus","2-s2.0-84899874733"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33358"],["dc.identifier.url","http://www.scopus.com/inward/record.url?eid=2-s2.0-84899874733&partnerID=MN8TOARS"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.eissn","0035-8711"],["dc.relation.issn","1365-2966"],["dc.title","Impact of baryonic streaming velocities on the formation of supermassive black holes via direct collapse"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1551"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","1561"],["dc.bibliographiccitation.volume","440"],["dc.contributor.author","Latif, A. H. M. Mahbub"],["dc.contributor.author","Schleicher, Dominik R. G."],["dc.contributor.author","Schmidt, W."],["dc.date.accessioned","2018-11-07T09:40:54Z"],["dc.date.available","2018-11-07T09:40:54Z"],["dc.date.issued","2014"],["dc.description.abstract","Observations of quasars at z > 6 report the existence of a billion solar mass black holes. Comprehending their formation in such a short time-scale is a matter of ongoing research. One of the most promising scenarios to assemble supermassive black holes is a monolithic collapse of protogalactic gas clouds in atomic cooling haloes with T-vir >= 10(4) K. In this paper, we study the amplification and impact of magnetic fields during the formation of seed black holes in massive primordial haloes. We perform high-resolution cosmological magnetohydrodynamic simulations for four distinct haloes and follow their collapse for a few free-fall times until the simulations reach a peak density of 7 x 10(-10) g cm(-3). Our findings show that irrespective of the initial seed field, the magnetic field strength reaches a saturated state in the presence of strong accretion shocks. Under such conditions, the growth time becomes very short and amplification occurs rapidly within a small fraction of the free-fall time. We find that the presence of such strong magnetic fields provides additional support against gravity and helps in suppressing fragmentation. Massive clumps of a few hundred solar masses are formed at the end of our simulations and high accretion rates of 1 M-circle dot yr(-1) are observed. We expect that in the presence of such accretion rates, the clumps will grow to form supermassive stars of similar to 10(5) M-circle dot. Overall, the role of the magnetic fields seems supportive for the formation of massive black holes."],["dc.identifier.doi","10.1093/mnras/stu357"],["dc.identifier.isi","000334742200046"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33603"],["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","Magnetic fields during the formation of supermassive black holes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]