bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finding and characterising WHIM structures using the luminosity density method
Authors: Nevalainen Jukka , Liivamägi L. J. , Tempel E. , Branchini E. , Roncarelli M. , Giocoli C. , Heinämäki P. , Saar E. , Bonamente M. , Einasto M. , Finoguenov A. , Kaastra J. , Lindfors E. , Nurmi P. , Ueda Y. 
Published: October 2016

AbstractWe have developed a new method to approach the missing baryons problem. We assume that the missing baryons reside in a form of Warm Hot Intergalactic Medium, i.e. the WHIM. Our method consists of (a) detecting the coherent large scale structure in the spatial distribution of galaxies that traces the Cosmic Web and that in hydrodynamical simulations is associated to the WHIM, (b) mapping its luminosity into a galaxy luminosity density field, (c) using numerical simulations to relate the luminosity density to the density of the WHIM, (d) applying this relation to real data to trace the WHIM using the observed galaxy luminosities in the Sloan Digital Sky Survey and 2dF redshift surveys. In our application we find evidence for the WHIM along the line of sight to the Sculptor Wall, at redshifts consistent with the recently reported X-ray absorption line detections. Our indirect WHIM detection technique complements the standard method based on the detection of characteristic X-ray absorption lines, showing that the galaxy luminosity density is a reliable signpost for the WHIM. For this reason, our method could be applied to current galaxy surveys to optimise the observational strategies for detecting and studying the WHIM and its properties. Our estimates of the WHIM hydrogen column density NH in Sculptor agree with those obtained via the X-ray analysis. Due to the additional NH estimate, our method has potential for improving the constrains of the physical parameters of the WHIM as derived with X-ray absorption, and thus for improving the understanding of the missing baryons problem.
Magnetogenesis at Cosmic Dawn
Authors: Durrive J-B. , Langer M. 
Published: October 2016

AbstractWe present a mechanism for generating cosmological magnetic fields during the Epoch of Reionization, based on the photoionization of intergalactic hydrogen. A general formula is presented, together with an example numerical application which yields magnetic field strengths between 10−23 to 10−19 G on intersource scales. This mechanism, which operates all along Reionization around any ionizing source, participates to the premagnetization of the whole intergalactic medium. Also, the spatial configuration of these fields may help discriminate them from those produced by other mechanisms in future observations.
Hierarchical formation of Dark Matter Halos near the Free Streaming Scale, and Their Implications on Indirect Dark Matter Search
Authors: Ishiyama Tomoaki 
Published: October 2016

AbstractThe smallest dark matter halos are formed first in the early universe. According to recent studies, the central density cusp is much steeper in these halos than in larger halos and scales as ρ ∝ r−(1.5−1.3). We present results of very large cosmological N-body simulations of the hierarchical formation and evolution of halos over a wide mass range, beginning from the formation of the smallest halos. We confirmed early studies that the inner density cusps are steeper in halos at the free streaming scale. The cusp slope gradually becomes shallower as the halo mass increases. The slope of halos 50 times more massive than the smallest halo is approximately -1.3. The concentration parameter is nearly independent of halo mass, and ruling out simple power law mass-concentration relations. The steeper inner cusps of halos near the free streaming scale enhance the annihilation luminosity of a Milky Way sized halo between 12 to 67%.
How do galaxies build up their spin in the cosmic web?
Authors: Welker Charlotte , Dubois Yohan , Pichon Christophe , Devriendt Julien , Peirani Sebastien 
Published: October 2016

AbstractUsing the Horizon-AGN simulation we find a mass dependent spin orientation trend for galaxies: the spin of low-mass, rotation-dominated, blue, star-forming galaxies are preferentially aligned with their closest filament, whereas high-mass, velocity dispersion- supported, red quiescent galaxies tend to possess a spin perpendicular to these filaments. We explore the physical mechanisms driving galactic spin swings and quantify how much mergers and smooth accretion re-orient them relative to their host filaments.
Gaseous discs at intermediate redshifts from kinematic data modelling
Authors: Kipper R. , Tamm A. , Tenjes P. , Tempel E. 
Published: October 2016

AbstractOur purpose is to measure thickness of gaseous discs in 0 < z < 1.2 galaxies. As gas dispersions are sensitive to scale height of gaseous discs, we model the kinematics of galaxies using Jeans equations. The resulting thicknesses of gaseous discs at higher redshifts are more thicker (and arbitrary) while nearby ones are thinner. We also found that clumpiness of galaxy is a possible indicator of the gas disc thickness.
Alignments of galaxies and halos in hydrodynamical simulations
Authors: Pahwa Isha , Libeskind Noam I. 
Published: October 2016

AbstractWe use a 200 h−1Mpc cosmological hydrodynamical simulation to examine the alignments of galaxies with respect to the host halo. We do separate study for the different components of the halo, such as stars, gas and dark matter. We show that angular momentum of gas is more aligned with the angular momentum of host halo compared with the stellar component.
Metallicity evolution in mergers of disk galaxies with black holes
Authors: Rantala Antti , Johansson Peter H. 
Published: October 2016

AbstractWe use the TreeSPH simulation code Gadget-3 including a recently improved smoothed particle hydrodynamics (SPH) module, a detailed metallicity evolution model and sophisticated subresolution feedback models for supernovae and supermassive black holes in order to study the metallicity evolution in disk galaxy mergers. In addition, we examine the simulated morphology, star formation histories, metallicity gradients and kinematic properties of merging galaxies and merger remnants. We will compare our simulation results with observations of the early-type Centaurus A galaxy and the currently colliding Antennae galaxies.
Void Dynamics
Authors: Padilla Nelson D. , Paz Dante , Lares Marcelo , Ceccarelli Laura , Lambas Diego Garcí a , Cai Yan-Chuan , Li Baojiu 
Published: October 2016

AbstractCosmic voids are becoming key players in testing the physics of our Universe.
Here we concentrate on the abundances and the dynamics of voids as these are among the best candidates
to provide information on cosmological parameters. Cai, Padilla & Li (2014)
use the abundance of voids to tell apart Hu & Sawicki f(R) models from General Relativity. An interesting
result is that even though, as expected, voids in the dark matter field are emptier in f(R) gravity due to the fifth force expelling
away from the void centres, this result is reversed when haloes are used to find voids. The abundance of voids in this case
becomes even lower in f(R) compared to GR for large voids. Still, the differences are significant and this
provides a way to tell apart these models. The velocity field differences between f(R) and GR, on the other hand, are
the same for halo voids and for dark matter voids.
Paz et al. (2013), concentrate on the velocity profiles around voids. First they show the necessity
of four parameters to describe the density profiles around voids given two distinct void
populations, voids-in-voids and voids-in-clouds. This profile is used to predict peculiar velocities around voids,
and the combination of the latter with void density profiles allows the construction of model
void-galaxy cross-correlation functions with redshift space distortions. When these models
are tuned to fit the measured correlation functions for voids and galaxies in the Sloan
Digital Sky Survey, small voids are found to be of the void-in-cloud type, whereas larger
ones are consistent with being void-in-void. This is a novel result that is obtained
directly from redshift space data around voids. These profiles can be used to
remove systematics on void-galaxy Alcock-Pacinsky tests coming from redshift-space distortions.
Measuring the growth rate of structure around cosmic voids
Authors: Hawken A. J. , Michelett D. , Granett B. , Iovino A. , Guzzo L. 
Published: October 2016

AbstractUsing an algorithm based on searching for empty spheres we identified 245 voids in the VIMOS Public Extragalactic Redshift Survey (VIPERS). We show how by modelling the anisotropic void-galaxy cross correlation function we can probe the growth rate of structure.
Characterising the local void with the X-ray cluster survey REFLEX II
Authors: Collins Chris A. , Böhringer Hans , Bristow Martyn , Chon Gayoung 
Published: October 2016

AbstractClaims of a significant underdensity or void in the density distribution on scales out to ≃ 300 Mpc have recently been made using samples of galaxies. We present the results of an alternative test of the matter distribution on these scales using clusters of galaxies, which provide an independent and powerful probe of large-scale structure. We study the density distribution of X-ray clusters from the ROSAT-based REFLEX II catalogue, which covers a contiguous area of 4.24 steradians in the southern hempsphere (34% of the entire sky). Using the normalised comoving number density of clusters we find evidence for an underdensity (30-40%), out to z∼ 0.04, equivalent to ≃170 Mpc and with a significance of 3.4σ. On scales between 300 Mpc and 1 Gpc the distribution of REFLEX II clusters is consistent with being uniform. We also confirm recent results that the underdensity has a large contribution from the direction of the South Galactic Cap region, but is not significant in the direction of the Northern Galactic Cap as viewed from the southern sky. Both the limited size of the detected underdensity and its lack of isotropy, argue against the idea that the Type Ia supernovae data can be explained without the need for dark energy.
Distinguishing f(R) gravity with cosmic voids
Authors: Zivick P. , Sutter P. M. 
Published: October 2016

AbstractWe use properties of void populations identified in N-body simulations to forecast the ability of upcoming galaxy surveys to differentiate models of f(R) gravity from \lcdm cosmology. We analyze simulations designed to mimic the densities, volumes, and clustering statistics of upcoming surveys, using the public {\tt VIDE} toolkit. We examine void abundances as a basic probe at redshifts 1.0 and 0.4. We find that stronger f(R) coupling strengths produce voids up to ∼20% larger in radius, leading to a significant shift in the void number function. As an initial estimate of the constraining power of voids, we use this change in the number function to forecast a constraint on the coupling strength of Δ fR0 = 10-5.
Observations of dwarfs in nearby voids: implications for galaxy formation and evolution
Authors: Pustilnik Simon A. 
Published: October 2016

AbstractThe intermediate results of the ongoing study of deep samples of ∼200 galaxies residing in nearby voids, are presented. Their properties are probed via optical spectroscopy, ugri surface photometry, and HI 21-cm line measurements, with emphasis on their evolutionary status. We derive directly the hydrogen mass M(HI), the ratio M(HI)/LB and the evolutionary parameter gas-phase O/H. Their luminosities and integrated colours are used to derive stellar mass M* and the second evolutionary parameter – gas mass-fraction fg). The colours of the outer parts, typically representative of the galaxy oldest stellar population, are used to estimate the upper limits on time since the beginning of the main SF episode. We compare properties of void galaxies with those of the similar late-type galaxies in denser environments. Most of void galaxies show smaller O/H for their luminosity, in average by ∼30\%, indicating slower evolution. Besides, the fraction of ∼10\% of the whole void sample or ∼30\% of the least luminous void LSB dwarfs show the oxygen deficiency by a factor of 2–5. The majority of this group appear very gas-rich, with fg ∼(95–99)%, while their outer parts appear rather blue, indicating the time of onset of the main star-formation episode of less than 1–4 Gyr. Such unevolved LSBD galaxies appear not rare among the smallest void objects, but turned out practically missed to date due to the strong observational selection effects. Our results evidense for unusual evolutionary properties of the sizable fraction of void galaxies, and thus, pose the task of better modelling of dwarf galaxy formation and evolution in voids.
Surveying for Dwarf Galaxies Within Voids FN2 and FN8
Authors: McNeil Stephen , Draper Chris , Moody J. Ward 
Published: October 2016

AbstractThe presence or absence of dwarf galaxies with Mr' > -14 in low-density volumes correlates with dark matter halos and how they affect galaxy formation. We are conducting a redshifted Hα imaging survey for dwarf galaxies with Mr' > -13 in the heart of the well-defined voids FN2 and FN8 using the KPNO 4m Mayall telescope and Mosaic Imager. These data have furnished over 600 strong candidates in a four square degree area. Follow-up spectra finding none of these candidates to be within the void volumes will constrain the dwarf population there to be 2 to 8% of the cosmic mean. Conversely, finding even one Hα dwarf in the void heart will challenge several otherwise successful theories of large-scale structure formation.
Probing the accelerating Universe with redshift-space distortions in VIPERS
Authors: de la Torre Sylvain 
Published: October 2016

AbstractWe present the first measurement of the growth rate of structure at z=0.8. It has been obtained from the redshift-space distortions observed in the galaxy clustering pattern in the VIMOS Public Redshift survey (VIPERS) first data release. VIPERS is a large galaxy redshift survey probing the large-scale structure at 0.5 < z < 1.2 with an unprecedented accuracy. This measurement represents a new reference in the distant Universe, which has been poorly explored until now. We obtain σ8 = 0.47 ± 0.08 at z = 0.8 that is consistent with the predictions of standard cosmological models based on Einstein gravity. This measurement alone is however not accurate enough to allow the detection of possible deviations from standard gravity.
The impact of superstructures in the Cosmic Microwave Background
Authors: Ilić Stéphane , Langer Mathieu , Douspis Marian 
Published: October 2016

AbstractIn 2008, Granett et al. claimed a direct detection of the integrated Sachs-Wolfe (iSW) effect, through the stacking of CMB patches at the positions of identified superstructures. Additionally, the high amplitude of their measured signal was reported to be at odds with predictions from the standard model of cosmology. However, a closer inspection of these results prompts multiple questions, more specifically about the amplitude and significance of the expected signal. We propose here an original theoretical prediction of the iSW effect produced by such superstructures. We use simulations based on GR and the LTB metric to reproduce cosmic structures and predict their exact theoretical iSW effect on the CMB. The amplitudes predicted with this method are consistent with the signal measured when properly accounting the contribution of the non-negligible (and fortuitous) primordial CMB fluctuations to the total signal. It also highlights the tricky nature of stacking measurements and their interpretation.
Faraday rotation in CMB maps
Authors: Ruiz-Granados Beatriz , Battaner Eduardo , Florido Estrella 
Published: October 2016

AbstractWMAP CMB polarization maps have been used to detect a low signal of Faraday Rotation (FR). If this detection is not interpreted as simple noise, it could be produced:at the last scattering surface (LSS) (z=1100), being primordial,at Reionization (z=10),in the Milky Way.The second interpretation is favoured here. In this case magnetic fields at Reionization with peak values of the order of 10-8 G should produce this observational FR.
Evolution of low-frequency contribution in emission of steep-spectrum radio sources
Authors: Miroshnichenko Alla P. 
Published: October 2016

AbstractWe consider evolution properties of galaxies and quasars with steep radio spectrum at the decametre band from the UTR-2 catalogue. The ratios of source's monochromatic luminosities at the decametre and high-frequency bands display the dependence on the redshift, linear size, characteristic age of examined objects. At that, the mean values of corresponding ratios for considered galaxies and quasars have enough close quantities,testifying on the unified model of sources. We analyse obtained relations for two types of steep-spectrum sources (with linear steep spectrum (S) and low-frequency steepness after a break (C+)) from the UTR-2 catalogue.
A High Throughput Phenotypic Screening reveals compounds that counteract premature osteogenic differentiation of HGPS iPS-derived mesenchymal stem cells
Authors: Lo Cicero Alessandra , Jaskowiak Anne-Laure , Egesipe Anne-Laure , Tournois Johana , Brinon Benjamin , Pitrez Patricia R. , Ferreira Lino , de Sandre-Giovannoli Annachiara , Levy Nicolas , Nissan Xavier 
Published: October 2016

AbstractHutchinson-Gilford progeria syndrome (HGPS) is a rare fatal genetic disorder that causes systemic accelerated aging in children. Thanks to the pluripotency and self-renewal properties of induced pluripotent stem cells (iPSC), HGPS iPSC-based modeling opens up the possibility of access to different relevant cell types for pharmacological approaches. In this study, 2800 small molecules were explored using high-throughput screening, looking for compounds that could potentially reduce the alkaline phosphatase activity of HGPS mesenchymal stem cells (MSCs) committed into osteogenic differentiation. Results revealed seven compounds that normalized the osteogenic differentiation process and, among these, all-trans retinoic acid and 13-cis-retinoic acid, that also decreased progerin expression. This study highlights the potential of high-throughput drug screening using HGPS iPS-derived cells, in order to find therapeutic compounds for HGPS and, potentially, for other aging-related disorders.
Comprehensive transcriptional and functional analyses of melatonin synthesis genes in cassava reveal their novel role in hypersensitive-like cell death
Authors: Wei Yunxie , Hu Wei , Wang Qiannan , Liu Wei , Wu Chunjie , Zeng Hongqiu , Yan Yu , Li Xiaolin , He Chaozu , Shi Haitao 
Published: October 2016

AbstractMelatonin is a widely known hormone in animals. Since melatonin was discovered in plants, more and more studies highlight its involvement in a wide range of physiological processes including plant development and stress responses. Many advances have been made in the terms of melatonin-mediated abiotic stress resistance and innate immunity in plants, focusing on model plants such as rice and Arabidopsis. In this study, 7 melatonin synthesis genes were systematically analyzed in cassava. Quantitative real-time PCR showed that all these genes were commonly regulated by melatonin, flg22, Xanthomonas axonopodis pv manihotis (Xam) and hydrogen peroxide (H2O2). Transient expression in Nicotiana benthamiana revealed the subcellular locations and possible roles of these melatonin synthesis genes. Notably, we highlight novel roles of these genes in hypersensitive-like cell death, as confirmed by the results of several physiological parameters. Moreover, transient expression of these genes had significant effects on the transcripts of reactive oxygen species (ROS) accumulation and defense-related genes, and triggered the burst of callose depositions and papillae-associated plant defense, indicating the possible role of them in plant innate immunity. Taken together, this study reveals the comprehensive transcripts and putative roles of melatonin synthesis genes as well as melatonin in immune responses in cassava.
Flutter Phenomenon in Flow Driven Energy Harvester–A Unified Theoretical Model for “Stiff” and “Flexible” Materials
Authors: Chen Yu , Mu Xiaojing , Wang Tao , Ren Weiwei , Yang Ya , Wang Zhong Lin , Sun Chengliang , Gu Alex Yuandong 
Published: October 2016

AbstractHere, we report a stable and predictable aero-elastic motion in the flow-driven energy harvester, which is different from flapping and vortex-induced-vibration (VIV). A unified theoretical frame work that describes the flutter phenomenon observed in both “stiff” and “flexible” materials for flow driven energy harvester was presented in this work. We prove flutter in both types of materials is the results of the coupled effects of torsional and bending modes. Compared to “stiff” materials, which has a flow velocity-independent flutter frequency, flexible material presents a flutter frequency that almost linearly scales with the flow velocity. Specific to “flexible” materials, pre-stress modulates the frequency range in which flutter occurs. It is experimentally observed that a double-clamped “flexible” piezoelectric P(VDF-TrFE) thin belt, when driven into the flutter state, yields a 1,000 times increase in the output voltage compared to that of the non-fluttered state. At a fixed flow velocity, increase in pre-stress level of the P(VDF-TrFE) thin belt up-shifts the flutter frequency. In addition, this work allows the rational design of flexible piezoelectric devices, including flow-driven energy harvester, triboelectric energy harvester, and self-powered wireless flow speed sensor.
Spatiotemporal properties of microsaccades: Model predictions and experimental tests
Authors: Zhou Jian-Fang , Yuan Wu-Jie , Zhou Zhao 
Published: October 2016

AbstractMicrosaccades are involuntary and very small eye movements during fixation. Recently, the microsaccade-related neural dynamics have been extensively investigated both in experiments and by constructing neural network models. Experimentally, microsaccades also exhibit many behavioral properties. It’s well known that the behavior properties imply the underlying neural dynamical mechanisms, and so are determined by neural dynamics. The behavioral properties resulted from neural responses to microsaccades, however, are not yet understood and are rarely studied theoretically. Linking neural dynamics to behavior is one of the central goals of neuroscience. In this paper, we provide behavior predictions on spatiotemporal properties of microsaccades according to microsaccade-induced neural dynamics in a cascading network model, which includes both retinal adaptation and short-term depression (STD) at thalamocortical synapses. We also successfully give experimental tests in the statistical sense. Our results provide the first behavior description of microsaccades based on neural dynamics induced by behaving activity, and so firstly link neural dynamics to behavior of microsaccades. These results indicate strongly that the cascading adaptations play an important role in the study of microsaccades. Our work may be useful for further investigations of the microsaccadic behavioral properties and of the underlying neural dynamical mechanisms responsible for the behavioral properties.