Behrens, Christoph

[["dc.bibliographiccitation.firstpage","A31"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","614"],["dc.contributor.author","Behrens, Christoph"],["dc.contributor.author","Byrohl, Chris"],["dc.contributor.author","Saito, Shun"],["dc.contributor.author","Niemeyer, Jens C."],["dc.date.accessioned","2020-07-01T08:28:01Z"],["dc.date.available","2020-07-01T08:28:01Z"],["dc.date.issued","2017"],["dc.description.abstract","Lyman-$\\alpha$ emitters (LAEs) are a promising probe of the large-scale structure at high redshift, \\gtrsim 2$. In particular, the Hobby-Eberly Telescope Dark Energy Experiment aims at observing LAEs at 1.9 $<z<$ 3.5 to measure the Baryon Acoustic Oscillation (BAO) scale and the Redshift-Space Distortion (RSD). However, Zheng et al. (2011) pointed out that the complicated radiative transfer (RT) of the resonant Lyman-$\\alpha$ emission line generates an anisotropic selection bias in the LAE clustering on large scales, \\gtrsim 10$ Mpc. This effect could potentially induce a systematic error in the BAO and RSD measurements. Also, Croft et al. (2016) claims an observational evidence of the effect in the Lyman-$\\alpha$ intensity map, albeit statistically insignificant. We aim at quantifying the impact of the Lyman-$\\alpha$ RT on the large-scale galaxy clustering in detail. For this purpose, we study the correlations between the large-scale environment and the ratio of an apparent Lyman-$\\alpha$ luminosity to an intrinsic one, which we call the 'observed fraction', at <z<6$. We apply our Lyman-$\\alpha$ RT code by post-processing the full Illustris simulations. We simply assume that the intrinsic luminosity of the Lyman-$\\alpha$ emission is proportional to the star formation rate of galaxies in Illustris, yielding a sufficiently large sample of LAEs to measure the anisotropic selection bias. We find little correlations between large-scale environment and the observed fraction induced by the RT, and hence a smaller anisotropic selection bias than what was claimed by Zheng et al. (2011). We argue that the anisotropy was overestimated in the previous work due to the insufficient spatial resolution: it is important to keep the resolution such that it resolves the high density region down to the scale of the interstellar medium, $\\sim1$ physical kpc. (abridged)"],["dc.identifier.arxiv","1710.06171v2"],["dc.identifier.doi","10.1051/0004-6361/201731783"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/66816"],["dc.language.iso","en"],["dc.relation.eissn","1432-0746"],["dc.relation.issn","0004-6361"],["dc.title","The impact of Lyman-$α$ radiative transfer on large-scale clustering in the Illustris simulation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","043519"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Physical Review D"],["dc.bibliographiccitation.volume","95"],["dc.contributor.author","Du, Xiaolong"],["dc.contributor.author","Behrens, Christoph"],["dc.contributor.author","Niemeyer, Jens C."],["dc.contributor.author","Schwabe, Bodo"],["dc.date.accessioned","2020-12-10T18:25:21Z"],["dc.date.available","2020-12-10T18:25:21Z"],["dc.date.issued","2017"],["dc.description.abstract","In the context of structure formation with ultralight axion dark matter, we offer an alternative explanation for the mass relation of solitonic cores and their host halos observed in numerical simulations. Our argument is based entirely on the mass gain that occurs during major mergers of binary cores and largely independent of the initial core-halo mass relation assigned to hosts that have just collapsed. We find a relation between the halo mass M-h and corresponding core mass M-c, M-c proportional to M-h(2 beta-1), where (1-beta) is the core mass loss fraction. Following the evolution of core masses in stochastic merger trees, we find empirical evidence for our model. Our results are useful for statistically modeling the effects of dark matter cores on the properties of galaxies and their substructures in axion dark matter cosmologies."],["dc.identifier.doi","10.1103/PhysRevD.95.043519"],["dc.identifier.eissn","2470-0029"],["dc.identifier.isi","000394663900007"],["dc.identifier.issn","2470-0010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/75661"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","2470-0029"],["dc.relation.issn","2470-0010"],["dc.title","Core-halo mass relation of ultralight axion dark matter from merger history"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Physical Review D"],["dc.bibliographiccitation.volume","102"],["dc.contributor.author","Schwabe, Bodo"],["dc.contributor.author","Gosenca, Mateja"],["dc.contributor.author","Behrens, Christoph"],["dc.contributor.author","Niemeyer, Jens C."],["dc.contributor.author","Easther, Richard"],["dc.date.accessioned","2021-04-14T08:31:33Z"],["dc.date.available","2021-04-14T08:31:33Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.1103/PhysRevD.102.083518"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/83637"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation.eissn","2470-0029"],["dc.relation.issn","2470-0010"],["dc.title","Simulating mixed fuzzy and cold dark matter"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A5"],["dc.bibliographiccitation.firstpage","A5"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","556"],["dc.contributor.author","Behrens, C."],["dc.contributor.author","Niemeyer, J."],["dc.date.accessioned","2018-11-07T09:21:41Z"],["dc.date.accessioned","2020-07-16T12:45:12Z"],["dc.date.available","2018-11-07T09:21:41Z"],["dc.date.available","2020-07-16T12:45:12Z"],["dc.date.issued","2013"],["dc.description.abstract","We investigate the correlations between the observed fraction of Lyman alpha emission from star-forming galaxies and the large scale structure by post-processing snapshots of a large, high resolution hydrodynamical simulation with a Lyman alpha radiative transfer code at redshifts z=4, 3, 2. We find correlations of the observed fraction with density, density gradient along the line of sight, velocity and velocity gradient along the line of sight, all within the same order of magnitude (tens of percent). Additionally, a correlation with the angular momentum of the dark matter halo is detected. In contrast to a previous study, we find no significant deformation of the 2-point correlation function due to selection effects from radiative transfer in the IGM within the limited statistics of the simulation volume."],["dc.description.sponsorship","DFG [SFB 963/1]"],["dc.identifier.doi","10.1051/0004-6361/201321172"],["dc.identifier.isi","000323893500005"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10865"],["dc.identifier.scopus","2-s2.0-84880680801"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/67191"],["dc.identifier.url","http://www.scopus.com/inward/record.url?eid=2-s2.0-84880680801&partnerID=MN8TOARS"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.eissn","1432-0746"],["dc.relation.issn","0004-6361"],["dc.rights","Goescholar"],["dc.rights.uri","https://goedoc.uni-goettingen.de/licenses"],["dc.title","Effects of Lyman-alpha scattering in the IGM on clustering statistics of Lyman-alpha emitters"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","941"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","951"],["dc.bibliographiccitation.volume","465"],["dc.contributor.author","Du, Xiaolong"],["dc.contributor.author","Behrens, Christoph"],["dc.contributor.author","Niemeyer, Jens C."],["dc.date.accessioned","2018-11-07T10:27:30Z"],["dc.date.accessioned","2020-07-20T07:56:31Z"],["dc.date.available","2018-11-07T10:27:30Z"],["dc.date.available","2020-07-20T07:56:31Z"],["dc.date.issued","2016"],["dc.description.abstract","We derive the halo mass function (HMF) for fuzzy dark matter (FDM) by solving the excursion set problem explicitly with a mass-dependent barrier function, which has not been done before. We find that compared to the naive approach of the Sheth--Tormen HMF for FDM, our approach has a higher cut off mass and the cut off mass changes less strongly with redshifts. Using merger trees constructed with a modified version of the Lacey & Cole formalism that accounts for suppressed small scale power and the scale-dependent growth of FDM haloes and the semi-analytic GALACTICUS code, we study the statistics of halo substructure including the effects from dynamical friction and tidal stripping. We find that if the dark matter is a mixture of cold dark matter (CDM) and FDM, there will be a suppression on the halo substructure on small scales which may be able to solve the Missing Satellites Problem faced by the pure CDM model. The suppression becomes stronger with increasing FDM fraction or decreasing FDM mass. Thus, it may be used to constrain the FDM model."],["dc.description.sponsorship","China Scholarship Council (CSC)"],["dc.identifier.arxiv","1608.02575v2"],["dc.identifier.doi","10.1093/mnras/stw2724"],["dc.identifier.isi","000393782000064"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/67223"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","Substructure of fuzzy dark matter haloes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]