Abstract
We investigate the role of halo concentration in the formation of intracluster light (ICL) in galaxy groups and clusters, as predicted by a state-of-the-art semianalytic model of galaxy ...formation, coupled with a set of high-resolution dark-matter-only simulations. The analysis focuses on how the fraction of ICL correlates with halo mass, concentration, and fraction of early-type galaxies (ETGs) in a large sample of groups and clusters with
13.0
≤
log
M
halo
≤
15.0
. The fraction of ICL follows a normal distribution, a consequence of the stochastic nature of the physical processes responsible for the formation of the diffuse light. The fractional budget of ICL depends on both halo mass (very weakly) until group scales, and concentration (remarkably). More interestingly, the ICL fraction is higher in more concentrated objects, a result of the stronger tidal forces acting in the innermost regions of the halos where the concentration is the quantity playing the most relevant role. Our model predictions do not show any dependence between the ICL and ETGs fractions, and so we instead suggest the concentration rather than the mass, as recently claimed, to be the main driver of the ICL formation. The diffuse light starts to form in groups via stellar stripping and mergers and later assembled in more-massive objects. However, the formation and assembly keep going on group/cluster scales at lower redshift through the same processes, mainly via stellar stripping in the vicinity of the central regions where tidal forces are stronger.
Background and Objective
Phelligridin D is a hispidin analogue from the mushroom Phellinus baumii that is widely used as a food source in East Asia. This study tested phelligridin D for the ...anti‐inflammatory effect and mechanism in lipopolysaccharide (LPS)‐induced human periodontal ligament cells (HPDLCs). The objective of this study was to clarify whether the anti‐inflammatory function of phelligridin D affects periodontal regeneration for supporting the HPDLCs of teeth.
Material and Methods
Primary HPDLCs were isolated from healthy teeth and then cultured. The anti‐inflammatory function, mechanism and differentiation molecules were verified with reactive oxygen species generation and western blot analysis in LPS‐induced HPDLCs.
Results
HPDLCs showed increased inflammatory molecules (intracellular adhesion molecule‐1 and vascular cell adhesion molecule‐1) and decreased osteogenic proteins (bone morphogenetic protein‐7, Osterix and runt‐related transcription factor 2) by LPS treatment. Phelligridin D decreased inflammatory molecules and increased osteogenic molecules via downregulation of the extracellular signal‐regulated kinase and c‐jun N‐terminal kinases pathway among the mitogen‐activated protein kinase, followed by blocking of nuclear factor kappa‐B translocation from cytosol to nucleus. In addition, phelligridin D showed antioxidant properties by reducing reactive oxygen species activity. Finally, the anti‐inflammatory and antioxidant function of phelligridin D promoted the periodontal differentiation of HPDLCs.
Conclusion
These results suggest that phelligridin D supports teeth on the alveolar bone against outside stress, and may be used as an anti‐inflammatory compound for the prevention of periodontitis or periodontal regenerative related disease.
We take advantage of an analytic model of galaxy formation coupled to the merger tree of an N-body simulation to study the roles of environment and stellar mass in the quenching of galaxies. The ...model has been originally set in order to provide the observed evolution of the stellar mass function as well as reasonable predictions of the star formation rate-stellar mass relation, from high redshift to the present time. We analyze the stellar mass and environmental quenching efficiencies and their dependence on stellar mass, halo mass (taken as a proxy for the environment), and redshift. Our analysis shows that the two quenching efficiencies are dependent on redshift and stellar and halo mass, and that the halo mass is also a good proxy for the environment. The environmental quenching increases with decreasing redshift and is inefficient below log M* ∼ 9.5, reaches the maximum value at log M* ∼ 10.5, and decreases again, becoming poorly efficient at very high stellar mass (log M* 11.5). Central and satellites galaxies are mass quenched differently: for the former, the quenching efficiency depends very weakly on redshift but strongly on stellar mass; for the latter, it strongly depends on both stellar mass and redshift in the range . According to the most recent observational results, we find that the two quenching efficiencies are not separable: intermediate-mass galaxies, as well as intermediate/massive galaxies in more massive halos, are environmentally quenched faster. At stellar masses lower than log M* 9.5, both quenching mechanisms become inefficient, independently of the redshift.
The environmental effect is commonly used to explain the excess of gas-poor galaxies in galaxy clusters. Meanwhile, the presence of gas-poor galaxies at cluster outskirts, where galaxies have not ...spent enough time to feel the cluster environmental effect, hints at the presence of preprocessing. Using cosmological hydrodynamic simulations on 16 clusters, we investigate the mechanisms of gas depletion of galaxies found inside clusters. The gas-depletion mechanisms can be categorized into three channels based on where and when they took place. First, 34% of our galaxies are gas poor before entering clusters ("preprocessing"). They are mainly satellites that have undergone the environmental effect inside group halos. Second, 43% of the sample quickly became gas deficient in clusters before the first pericentric pass ("fast cluster processing"). Some of them were group satellites that are low in gas at the time of cluster entry compared to the galaxies directly coming from the field. Even the galaxies with large gas fractions take this channel if they fall into massive clusters ( 1014.5 M ) or approach cluster centers through radial orbits. Third, 24% of our sample retain gas even after their first pericentric pass ("slow cluster processing") as they fall into the less massive clusters or have circular orbits. The relative importance of each channel varies with a cluster's mass, while the exact degree of significance is subject to large uncertainties. Group preprocessing accounts for one-third of the total gas depletion, but it also determines the gas fraction of galaxies at their cluster entry, which in turn determines whether a galaxy should take the fast or slow cluster processing.
A
bstract
The signal to noise ratio efficiency
ϵ
SNR
in axion dark matter searches has been estimated using large-statistic simulation data reflecting the background information and the expected ...axion signal power obtained from a real experiment. This usually requires a lot of computing time even with the assistance of powerful computing resources. Employing a Savitzky-Golay filter for background subtraction, in this work, we estimated a fully analytical
ϵ
SNR
without relying on large-statistic simulation data, but only with an arbitrary axion mass and the relevant signal shape information. Hence, our work can provide
ϵ
SNR
using minimal computing time and resources prior to the acquisition of experimental data, without the detailed information that has to be obtained from real experiments. Axion haloscope searches have been observing the coincidence that the frequency independent scale factor
ξ
is approximately consistent with the
ϵ
SNR
. This was confirmed analytically in this work, when the window length of the Savitzky-Golay filter is reasonably wide enough, i.e., at least 5 times the signal window.
Abstract
We investigate the diffuse light (DL) content of dark matter haloes in the mass range
11.5
≤
log
M
halo
≤
13
, a range that also includes the dark matter halo of the Milky Way, taking ...advantage of a state-of-the-art semianalytic model run on the merger trees extracted from a set of high-resolution cosmological simulations. The fraction of DL in such relatively small haloes is found to progressively decrease from the high- to the low-mass end, in good agreement with analytic and numerical results from simulations, and in good agreement also with the fraction of the DL observed in the Milky Way and M31. Haloes with different masses have different efficiencies in producing DL:
log
M
halo
≃
13
is found to be the characteristic halo mass where the production of DL is the most efficient, while the overall efficiency decreases at both larger and smaller scales (this work). The DL content in this range of halo mass is the result of stellar stripping due to tidal interaction between satellites and their hosts (95%) and mergers between satellites and the central galaxy (5%), with preprocessed material, a subchannel of mergers and stripping, and so already included in the 100%, that contributes no more than 8% on average. The halo concentration is the main driver of the DL formation: more concentrated haloes have higher DL fractions that come from the stripping of more massive satellites in the high-halo-mass end, while dwarfs contribute mostly in the low-halo-mass end.
Using the Horizon-AGN simulation data, we study the relative role of mergers and environmental effects in shaping the spin of early-type galaxies (ETGs) after z 1. We follow the spin evolution of ...10,037 color-selected ETGs more massive than that are divided into four groups: cluster centrals (3%), cluster satellites (33%), group centrals (5%), and field ETGs (59%). We find a strong mass dependence of the slow rotator fraction, fSR, and the mean spin of massive ETGs. Although we do not find a clear environmental dependence of fSR, a weak trend is seen in the mean value of the spin parameter driven by the satellite ETGs as they gradually lose their spin as their environment becomes denser. Galaxy mergers appear to be the main cause of total spin changes in 94% of the central ETGs of halos with , but only 22% of satellite and field ETGs. We find that non-merger-induced tidal perturbations better correlate with the galaxy spin down in satellite ETGs than in mergers. Given that the majority of ETGs are not central in dense environments, we conclude that non-merger tidal perturbation effects played a key role in the spin evolution of ETGs observed in the local (z < 1) universe.
In many wireless communications/radar applications, constant modulus sequences with low correlation sidelobes levels are desired. In this letter, we present an efficient optimization method to design ...them. Firstly, we formulate a fourth-order polynomial, but unconstrained, minimization problem. And then, a customized LBFGS (Limited-Memory Broyden Fletcher Goldfarb and Shanno) iterative algorithm is proposed to solve it approximately. Numerical examples show that the proposed approach compares favorably with the state-of-the-art approach.
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