Number Of Halos Research Articles

The Massive and Distant Clusters of WISE Survey 2: Second Data Release

We present the second data release of the Massive and Distant Clusters of WISE Survey 2 (MaDCoWS2). We expand from the equatorial first data release to most of the Dark Energy Camera Legacy Survey area, covering a total area of 6498 deg2. The catalog consists of 133,036 signal-to-noise ratio (S/N) ≥ 5 galaxy cluster candidates at 0.1 ≤ z ≤ 2, including 6790 candidates at z > 1.5. We train a convolutional neural network (CNN) to identify spurious detections and include CNN-based cluster probabilities in the final catalog. We also compare the MaDCoWS2 sample with literature catalogs in the same area. The larger sample provides robust results that are consistent with our first data release. At S/N ≥ 5, we rediscover 59%–91% of clusters in existing catalogs that lie in the unmasked area of MC2. The median positional offsets are under 250 kpc, and the standard deviation of the redshifts is 0.031(1 + z). We fit a redshift-dependent power law to the relation between MaDCoWS2 S/N and observables from existing catalogs. Over the redshift ranges where the surveys overlap with MaDCoWS2, the lowest scatter is found between S/N and observables from optical/infrared surveys. We also assess the performance of our method using a mock light cone measuring purity and completeness as a function of cluster mass. The purity is above 90%, and we estimate the 50% completeness threshold at a virial mass of log(M/M ⊙) ≈ 14.3. The completeness estimate is uncertain due to the small number of massive halos in the light cone, but consistent with the recovery fraction found by comparing to other cluster catalogs.

The effect of vitamin D in vitro supplementation on sperm deoxyribonucleic acid fragmentation.

This study aimed to identify the direct effect of vitamin D on sperm DNA integrity after swim-up preparation. Normozoospermia samples were gathered from 12 men and assessed for their baseline characteristics, including DNA Fragmentation Index (DFI). Each sample was then prepared using the swim-up method. Half of the samples were incubated with vitamin D, while the other half were incubated with a standard sperm-washing medium. Vitamin D significantly reduced the DFI compared to the baseline (5.5 ± 3.4% versus 17.6 ± 4.2%; p < 0.001) and the swim-up-only group (5.5 ± 3.4% versus 12.0 ± 4.2%; p < 0.001). Microscopic examination reflected these results, showing a reduction in the number of small halos and no halos with an increased appearance of large to medium-sized halos. These results suggest that vitamin D incubation is valuable in protecting sperm from DNA damage that develops during sperm preparation. However, additional investigation is warranted to explore other preparation methods and to elucidate the underlying mechanisms.

JWST’s PEARLS: 119 multiply imaged galaxies behind MACS0416, lensing properties of caustic crossing galaxies, and the relation between halo mass and number of globular clusters at z = 0.4

We present a new lens model for the ɀ = 0.396 galaxy cluster MACS J0416.1 –2403 based on a previously known set of 77 spectroscop-ically confirmed, multiply imaged galaxies plus an additional set of 42 candidate multiply imaged galaxies from past HST and new JWST data. The new galaxies lack spectroscopic redshifts but have geometric and/or photometric redshift estimates that are presented here. The new model predicts magnifications and time delays for all multiple images. The full set of constraints totals 343, constituting the largest sample of multiple images lensed by a single cluster to date. Caustic-crossing galaxies lensed by this cluster are especially interesting. Some of these galaxies show transient events, most of which are interpreted as micro-lensing of stars at cosmological distances. These caustic-crossing arcs are expected to show similar events in future, deeper JWST observations. We provide time delay and magnification models for all these arcs. The time delays and the magnifications for different arcs are generally anti-correlated. In the major sub-halos of the cluster, the dark-matter mass from our lens model correlates well with the observed number of globular clusters, as expected from N-body simulations. This confirms earlier results, derived at lower redshifts, which suggest that globular clusters can be used as powerful mass proxies for the halo masses when lensing constraints are scarce or not available.

The Measurement of the Splash-back Radius of Dark Matter Halos

In the hierarchical evolution framework of cosmology, larger halos grow through matter accretion and halo mergers. To clarify halo evolution, we need to define the halo mass and radius physically. However, the pseudoevolution problem makes the process difficult. Thus, we aim to measure the splash-back radius (R sp), a physically defined halo radius for a large number of halos with various mass and redshift, and to determine the most important parameters that affect it. We use the typical definition of splash-back radius as the radius with the steepest radial density profile. In this work, we measure the splash-back radius of dark matter halos within the mass of 1013 M ⊙ to 3 × 1015 M ⊙ and redshifts spanning 0.08–0.65. This is the measurement of the R sp in the largest range of halo mass and redshift. Using the shear catalog of the Dark Energy Camera Legacy Survey Data Release 8, we investigate the splash-back radius of halos associated with galaxies and galaxy clusters identified in the various catalogs. Our finding reveals a trend wherein massive halos demonstrate a larger splash-back radius, and the normalized splash-back radius (R sp/R 200m) shows a U-shaped mass evolution. The upturn in these relations mainly comes from the contribution of massive halos with low redshifts. We further find the splash-back radius increases with the peak height, while the normalized splash-back radius has a negative relation with the peak height. We also find that R sp ≳ R 200m for most halos, indicating their low accretion rates. Our result is consistent with previous literature across a wide range of mass, redshift, and peak height, as well as the simulation work from More et al.

Enhancing Morphological Measurements of the Cosmic Web with Delaunay Tessellation Field Estimation

The density fields constructed by traditional mass assignment methods are susceptible to irritating discreteness, which hinders morphological measurements of cosmic large-scale structure (LSS) through Minkowski functionals (MFs). To alleviate this issue, fixed-kernel smoothing methods are commonly used in the literature, at the expense of losing substantial structural information. In this work, we propose to measure MFs with the Delaunay tessellation field estimation (DTFE) technique, with the goal of maximizing the extraction of morphological information from sparse tracers. We perform our analyses starting from matter fields and progressively extending to halo fields. At the matter-field level, we elucidate how discreteness affects morphological measurements of LSS. Then, by comparing with the traditional Gaussian smoothing scheme, we preliminarily showcase the advantages of DTFE for enhancing measurements of MFs from sparse tracers. At the halo-field level, we first numerically investigate various systematic effects on MFs of DTFE fields, which are induced by finite voxel sizes, halo number densities, halo weightings, and redshift space distortions (RSDs), respectively. Then, we explore the statistical power of MFs measured with DTFE for extracting the cosmological information encoded in RSDs. We find that MFs measured with DTFE exhibit improvements by ∼2 orders of magnitude in discriminative power for RSD effects and by a factor of ∼3–5 in constraining power on the structure growth rate over the MFs measured with Gaussian smoothing. These findings demonstrate the remarkable enhancements in statistical power of MFs achieved by DTFE, showing enormous application potentials for our method in extracting various key cosmological information from galaxy surveys.

Quantifying the Tension between Cosmological Models and JWST Red Candidate Massive Galaxies

We develop a Python tool to estimate the tail distribution of the number of dark matter halos beyond a mass threshold and in a given volume in a light-cone. The code is based on the extended Press–Schechter model and is computationally efficient, typically taking a few seconds on a personal laptop for a given set of cosmological parameters. The high efficiency of the code allows a quick estimation of the tension between cosmological models and the red candidate massive galaxies released by the James Webb Space Telescope, as well as scanning the theory space with the Markov Chain Monte Carlo method. As an example application, we use the tool to study the cosmological implication of the candidate galaxies presented in Labbé et al. The standard Λ cold dark matter (ΛCDM) model is well consistent with the data if the star formation efficiency can reach ∼0.3 at high redshift. For a low star formation efficiency ϵ ∼ 0.1, the ΛCDM model is disfavored at ∼2σ–3σ confidence level.

Are odd radio circles virial shocks around massive galaxies? Implications for cosmic-ray diffusion in the circumgalactic medium

ABSTRACT Recently, a new population of circular radio (∼GHz) objects has been discovered at high Galactic latitudes, called the odd radio circles (ORCs). A fraction of the ORCs encircles massive galaxies in the sky with stellar mass ∼1011 M⊙ situated at z = 0.2–0.6, suggesting a possible physical connection. In this paper, we explore the possibility that these radio circles originate from the accretion shocks/virial shocks around massive (${\gtrsim} 10^{13}\, \ {\rm M}_\odot$) dark matter halo at z ∼ 0.5. We found that the radio flux density of the emitting shell is marginally consistent with the ORCs. We also find that pure advection of electrons from the shock results in a radio-emitting shell that is considerably narrower than the observed one due to strong inverse-Compton cooling of electrons. Instead, we show that the diffusion of cosmic-ray (CR) electrons plays a significant role in increasing the width of the shell. We infer a diffusion coefficient, $D_{\rm cr} \sim 10^{30}\ {\rm cm^2\, s^{-1}}$, consistent with the values expected for low-density circumgalactic medium (CGM). If ORCs indeed trace virial shocks, then our derived CR diffusion coefficient represents one of the few estimations available for the low-density CGM. Finally, we show that the apparent discrepancy between ORC and halo number density can be mitigated by considering an incomplete halo virialization and the limited radiation efficiency of shocks. This study therefore opens up new avenues to study such shocks and non-thermal particle acceleration within them. Furthermore, our results suggest that low-mass galaxies (≲1013 M⊙) may not show ORCs due to their significantly lower radio surface brightness.

ThePlanckclusters in the LOFAR sky

Context.Many galaxy clusters show diffuse cluster-scale emission in the form of radio halos, showing that magnetic fields and relativistic electrons are mixed in with the intracluster medium. There is in general agreement with the idea that the origin of radio halos is connected to turbulence generated during cluster mergers. Statistical studies of large samples of galaxy clusters in the radio band have the potential to unveil the connection between the properties of radio halos and the mass and dynamics of the host clusters.Aims.Previous studies were limited to massive clusters and were based on a small number of radio halos. The aim of this paper is to investigate the scaling relation between the radio power of radio halos and the mass of the host clusters at low frequencies and down to lower cluster masses.Methods.We analysed the clusters from the second catalogue ofPlanckSunyaev–Zel’dovich sources that lie within the 5634 deg2covered by the second Data Release of the LOFAR Two-meter Sky Survey. We derived the correlation between radio power and host cluster mass, and investigated the distribution of clusters without radio halos with respect to this correlation. We used X-ray observations to classify the dynamical state of clusters and investigated its effect on the power of radio halos.Results.Using different fitting methods, we found a correlation between the power of a radio halo at 150 MHz and the mass of its host cluster down to 3 × 1014 M⊙. For comparison with previous works, with the Bivariate Correlated Errors and intrinsic Scatter (BCES)Y|Xmethod, we obtained the slope of the correlationB = 3.55 ± 0.60 and the normalisationA = 1.1 ± 0.1. This correlation has a large scatter, part of which can be attributed to the different dynamical states of host clusters. We used two statistical tests to show that the distribution of clusters with and without (upper limits) radio halos in the mass–radio power diagram is not compatible with a single correlation and that it is also not compatible with clusters being uniformly distributed below the correlation.

Quijote-PNG: The Information Content of the Halo Mass Function

We study signatures of primordial non-Gaussianity (PNG) in the redshift-space halo field on nonlinear scales using a combination of three summary statistics, namely, the halo mass function (HMF), power spectrum, and bispectrum. The choice of adding the HMF to our previous joint analysis of the power spectrum and bispectrum is driven by a preliminary field-level analysis, in which we train graph neural networks on halo catalogs to infer the PNG f NL parameter. The covariance matrix and the responses of our summaries to changes in model parameters are extracted from a suite of halo catalogs constructed from the Quijote-png N-body simulations. We consider the three main types of PNG: local, equilateral, and orthogonal. Adding the HMF to our previous joint analysis of the power spectrum and bispectrum produces two main effects. First, it reduces the equilateral f NL predicted errors by roughly a factor of 2 while also producing notable, although smaller, improvements for orthogonal PNG. Second, it helps break the degeneracy between the local PNG amplitude, , and assembly bias, b ϕ , without relying on any external prior assumption. Our final forecasts for the PNG parameters are , , , on a cubic volume of , with a halo number density of , at z = 1, and considering scales up to .

Dark matter halo mass functions and density profiles from mass and energy cascade

Halo abundance and structure play a central role for modeling structure formation and evolution. Without relying on a spherical or ellipsoidal collapse model, we analytically derive the halo mass function and cuspy halo density (inner slope of −4/3) based on the mass and energy cascade theory in dark matter flow. The hierarchical halo structure formation leads to halo or particle random walk with a position-dependent waiting time tau _g. First, the inverse mass cascade from small to large scales leads to the halo random walk in mass space with tau _gpropto m_h^{-lambda }, where m_h is the halo mass and lambda is a halo geometry parameter with predicted value of 2/3. The corresponding Fokker-Planck solution for halo random walk in mass space gives rise to the halo mass function with a power-law behavior on small scale and exponential decay on large scale. This can be further improved by considering two different lambda for haloes below and above a critical mass scale m_h^*, i.e. a double-lambda halo mass function. Second, a double-gamma density profile can be derived based on the particle random walk in 3D space with a position-dependent waiting time tau _g propto Phi (r)^{-1} propto r^{-gamma }, where Phi is the gravitational potential and r is the particle distance to halo center. Theory predicts gamma =2/3 that leads to a cuspy density profile with an inner slope of −4/3, consistent with the predicted scaling laws from energy cascade. The Press-Schechter mass function and Einasto density profile are just special cases of proposed models. The small scale permanence can be identified due to the scale-independent rate of mass and energy cascade, where density profiles of different halo masses and redshifts converge to the -4/3 scaling law (rho _h propto r^{-4/3}) on small scales. Theory predicts the halo number density scales with halo mass as propto m_h^{-1.9}, while the halo mass density scales as propto m_h^{4/9}. Results were compared against the Illustris simulations. This new perspective provides a theory for nearly universal halo mass functions and density profiles.

Hermeian haloes: Extreme objects with two interactions in the past

Recent studies based on numerical models of the Local Group predict the existence of field haloes and galaxies that have visited both the Milky Way and M31 in the past, called Hermeian haloes. We extend this analysis beyond the Local Group using two high-resolution dark matter-only N-body simulations from the MultiDark suite. We define Hermeian haloes as field haloes which had close interactions with two other more massive field haloes in the past, called targets. We find that Hermeian haloes are a more extreme example of field haloes with interactions in the past than the well-known backsplash haloes that experienced only one interaction. Compared to backsplashers, Hermeians have more concentrated density profiles and tend to occupy more overdense regions. They also have higher velocities relative to their target haloes and relative to their neighbours within 1 h−1Mpc. Hermeian haloes can be found around every halo in the simulation (if the resolution is sufficient) and make up 0.4 to 2.3 per cent of the total number of field haloes (for haloes more massive than 1010h−1M⊙ and 3.3×107h−1M⊙, respectively), increasing to 10 per cent in overdense regions. They tend to be distributed close to the line connecting their targets, which may help to identify Hermeian haloes in observations. We also identify Local Group analogues in the simulation and find that about one-third (15 out of 49) of them contain Hermeian haloes if the distance between the two main haloes is below 1 h−1Mpc.

On the merger rate of primordial black holes in cosmic voids

Cosmic voids are known as underdense substructures of the cosmic web that cover a large volume of the Universe. It is known that cosmic voids contain a small number of dark matter halos, so the existence of primordial black holes (PBHs) in these secluded regions of the Universe is not unlikely. In this work, we calculate the merger rate of PBHs in dark matter halos structured in cosmic voids and determine their contribution to gravitational wave events resulting from black hole mergers recorded by the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO)-Advanced Virgo (aVirgo) detectors. Relying on the PBH scenario, the results of our analysis indicate that about 3∼4 annual events of binary black hole mergers out of all those recorded by the aLIGO-aVirgo detectors should belong to cosmic voids. We also calculate the redshift evolution of the merger rate of PBHs in cosmic voids. The results show that the evolution of the merger rate of PBHs has minimum sensitivity to the redshift changes, which seems reasonable while considering the evolution of cosmic voids. Finally, we specify the behavior of the merger rate of PBHs as a function of their mass and fraction in cosmic voids and we estimate R(MPBH,fPBH) relation, which is well compatible with our findings.

Beam optimization of a heavy ion microbeam for targeted irradiation of mitochondria in human cells

Mitochondria, organelles of the cytoplasm, are the power plants of the cell and thus their function is important for the survival of cells. Mitochondria are known to depolarize after targeted irradiation, but the effects on cells are still unclear. The aim of this work is to investigate the effects of mitochondrial depolarization on growth and survival of cells. We performed targeted irradiation with 55 MeV C5+-ions at the ion-microbeam SNAKE at the 14 MV tandem accelerator in Garching near Munich, with a beam spot size of ∼1 µm. Approx. 6% of the mitochondrial area was irradiated in 74 cells with 5,120 carbon ions homogenously distributed over a square area of 13.2 µm2. Cell growth was investigated by observing the cells for 3.5 days via live-cell phase-contrast microscopy and evaluating the number of vital cells. While the number of irradiated cells remained constant during the observation, the unirradiated control group showed exponential growth. An additional particle track detector test with polycarbonate revealed that 4% parasitic ions hit the cells up to 500 µm away from the target, forming a so-called halo and inducing a mean parasitic dose of (2 ± 2) Gy on the cells. This dose alone, when applied in cell nuclei, is large enough to reduce the survival and growth of cells significantly and overrides any effects caused by targeted irradiation of mitochondria. Subsequently, several methods to reduce the halo were investigated. A significant reduction in halo size and number of ions in the halo could be achieved by using C6+-ions instead of C5+-ions. The slit openings, correction of lens errors, and the beam spot size had minor influence on the halo size but could achieve a reduction in halo dose. Overall, a 97% reduction in halo area and a halving of halo dose were achieved.

P-105 The Reliability of Sperm Chromatin Dispersion (SCD) Test to Predict Assisted Reproductive Technology (ART) Treatments Outcomes -A Systematic Review and Meta-Analysis

Abstract Study question Is the sperm chromatin dispersion (SCD) test reliable for predicting reproductive technology (ART) treatment outcomes? Summary answer Assessment of DNA fragmentation using the SCD test failed to predict pregnancy or live births rates. What is known already The detrimental effect of high DNA fragmentation on semen quality, fertility, and poor ART outcomes has been well-studied in recent years. Still, it remains contentious. Several techniques can detect sperm DNA fragmentation, such as TUNEL, comet assay, and SCSA. Although these techniques have been implemented in many andrology laboratories, they remain complex, time-consuming, and expensive. On the other hand, the SCD test indirectly estimates the DNA fragmentation level by manually quantifying the number of halos representing nuclear dispersion after sperm lysis and acid denaturation. While the SCD test is commonly used, it remains subjected to bias and high variability. Study design, size, duration Systematic review and meta-analysis. A PRISMA-guided literature search in the English language was performed in January 2021 using PubMed/MEDLINE, Scopus, and Google scholar. We looked for rates of fertilization, cleavage rate embryos, implantation, clinical pregnancy, miscarriage, and live birth. MedCalc software using the random effects model was used, Sensitivity analysis was conducted to examine heterogeneity and the robustness of the results. Participants/materials, setting, methods After duplicate removal, 179 abstracts were assessed for eligibility, and 55 full-text articles were screened. Forty-one articles were included in the qualitative syntheses, and 16 were included in the quantitative synthesis, representing 6989 participants. Main results and the role of chance No significant difference was identified between the group with high SDF vs. low SDF regarding fertilization (SMD −0.334, 95% CI −0.695, 0.027, p = 0.07), clinical pregnancy (OR 0.901, 95% CI 0.719, 1.130, p = 0.367), miscarriage (OR 0.901, 95% CI 0.719, 1.130, p = 0.367) and live birth (OR 1.105, 95% CI 0.627, 1.946, p = 0.730) rates. The rates of cleavage stage embryos (SMD -1.153, 95% CI -2.113, −0.194, p = 0.019) and implantation (OR 0.472, 95% CI 0.303, 0.737, p = 0.001) were significantly lower in the group with high SDF vs. low SDF. Limitations, reasons for caution A high index of heterogeneity and publication bias was reported regarding fertilization (I2 = 93.23%, Egger’s test: intercept -5.29866, 95% CI -10.41, −0.19, p = 0.02) and cleavage-stage embryos(I2 = 98.49%, Egger’s test: intercept -14.02395, 95% CI -27.47, −0.57, p = 0.02) Wider implications of the findings Assessment of DNA fragmentation using the SCD test failed to predict pregnancy or live births. As the goal of ART is live birth, clinicians should consider the limited yield of this assay to predict the likelihood of live birth. Trial registration number NA

Starbursts in low-mass haloes at Cosmic Dawn. I. The critical halo mass for star formation

ABSTRACT The first stars, galaxies, star clusters, and direct-collapse black holes are expected to have formed in low-mass (∼105–109 M⊙) haloes at Cosmic Dawn (z ∼ 10–30) under conditions of efficient gas cooling, leading to gas collapse towards the centre of the halo. The halo mass cooling threshold has been analysed by several authors using both analytical models and numerical simulations, with differing results. Since the halo number density is a sensitive function of the halo mass, an accurate model of the cooling threshold is needed for (semi-)analytical models of star formation at Cosmic Dawn. In this paper, the cooling threshold mass is calculated (semi-)analytically, considering the effects of H2-cooling and formation (in the gas phase and on dust grains), cooling by atomic metals, Lyman-α cooling, photodissociation of H2 by Lyman–Werner photons (including self-shielding by H2), photodetachment of H− by infrared photons, photoevaporation by ionization fronts, and the effect of baryon streaming velocities. We compare the calculations to several high-resolution cosmological simulations, showing excellent agreement. We find that in regions of typical baryon streaming velocities, star formation is possible in haloes of mass ≳ 1–2 × 106 M⊙ for z ≳ 20. By z ∼ 8, the expected Lyman–Werner background suppresses star formation in all minihaloes below the atomic cooling threshold (Tvir = 104 K). The halo mass cooling threshold increases by another factor of ∼4 following reionization, although this effect is slightly delayed (z ∼ 4–5) because of effective self-shielding.

The halo bias for number counts on the light cone from relativistic N-body simulations

We present the halo number counts and its two-point statistics, the observable angular power spectrum, extracted for the first time from relativistic N-body simulations. The halo catalogues used in this work are built from the relativistic N-body code gevolution, and the observed redshift and angular positions of the sources are computed using a non-perturbative ray-tracing method, which includes all relativistic scalar contributions to the number counts. We investigate the validity and limitations of the linear bias prescription to describe our simulated power spectra. In particular, we assess the consistency of different bias measurements on large scales, and we estimate up to which scales a linear bias is accurate in modelling the data, within the statistical errors. We then test a second-order perturbative bias expansion for the angular statistics, on a range of redshifts and scales previously unexplored in this context, that is 0.4 ≤ z̅ ≤ 2 up to scales ℓ max ∼ 1000. We find that the angular power spectra at equal redshift can be modelled with high accuracy with a minimal extension of the number of bias parameters, that is using a two-parameter model comprising linear bias and tidal bias. We show that this model performs significantly better than a model without tidal bias but with quadratic bias as extra degree of freedom, and that the latter is inaccurate at z̅ ≥ 0.7. Finally, we extract from our simulations the cross-correlation of halo number counts and lensing convergence. We show that the estimate of the linear bias from this cross-correlation is consistent with the measurements based on the clustering statistics alone, and that it is crucial to take into account the effect of magnification in the halo number counts to avoid systematic shifts in the computed bias.

Effects of Vitrification Techniques on the Formation of Skin Cryobank of the Ocelot (Leopardus Pardalis)

BACKGROUND: Skin cryobanks represent important tools for the conservation of the maximum genetic representation of a population, especially those with a certain degree of threat to extinction, such as the ocelot. A relevant step towards the proper establishment of these banks is the definition of adequate cryopreservation techniques for the conservation of the skin. OBJECTIVE: We evaluated the effects of two different techniques [direct vitrification in cryovials (DVC) and solid-surface vitrification (SSV)] for the preservation of ear skin derived from ocelot. MATERIALS &amp; METHODS: For both techniques, we vitrified the ear skin using Dulbecco's modified Eagle's medium with 3.0 M dimethyl sulfoxide, 0.25 M sucrose, and 10% fetal bovine serum. Non-cryopreserved tissues were used as control (control group). All tissues were analyzed for their morphometric characteristics by conventional histology and morphological/functional analysis by cell ability during the culture. RESULTS: While tissues cryopreserved by DVC showed similar values for dermis thickness and number of perinuclear halos to the control, tissues cryopreserved by SSV showed similarities to the control regarding the number of melanocytes, percentage of collagen fibers, and numbers of viable cells by apoptosis analysis. Additionally, none of the vitrification techniques affected stratum corneum thickness, number of keratinocytes, tissue proliferative activity, cell viability, or metabolism. CONCLUSION: Both vitrification techniques (DVC and SSV) can be used for the conservation of ocelot skin; however, SSV guarantees a higher cellular quality after in vitro tissue culture in most of the parameters evaluated, such as viability, metabolism, and apoptosis analysis.

A Stochastic Theory of the Hierarchical Clustering. III. The Nonuniversality and Nonstationarity of the Halo Mass Function

In the framework of the stochastic theory for hierarchical clustering, we investigate the time-dependent solutions of the Fokker–Planck equation describing the statistics of dark matter halos, and discuss the typical timescales needed for these to converge toward stationary states, far away enough from initial conditions. Although we show that the stationary solutions can reproduce the outcomes of state-of-the-art N-body simulations at z ≈ 0 to great accuracy, one needs to go beyond to fully account for the cosmic evolution of the simulated halo mass function toward high redshift. Specifically, we demonstrate that the time-dependent solutions of the Fokker–Planck equation can describe, for reasonable initial conditions, the nonuniversal evolution of the simulated halo mass functions. Compared to standard theoretical estimates, our stochastic theory predicts a halo number density higher by a factor of several toward z ≳ 10, an outcome that can be helpful in elucidating early and upcoming data from JWST. Finally, we point out the relevance of our approach in designing, interpreting, and emulating present and future N-body experiments.

Population synthesis of pulsar wind nebulae and pulsar halos in the Milky Way

Context.The discovery of extended gamma-ray emission toward a number of middle-aged pulsars suggests the possibility of long-lived particle confinement beyond the classical pulsar wind nebula (PWN) stage. How this emerging source class can be extrapolated to a Galactic population remains unclear.Aims.We aim to evaluate how pulsar halos fit in existing TeV observations, under the assumption that all middle-aged pulsars develop halos similar to those observed toward the J0633+1746 or B0656+14 pulsars.Methods.We modeled the populations of supernova remnants, PWNe, and pulsar halos in the Milky Way. The PWN-halo evolutionary sequence is described in a simple yet coherent framework, and both kinds of objects are assumed to share the same particle injection properties. We then assessed the contribution of the different source classes to the very-high-energy emission from the Galaxy.Results.The synthetic population can be made consistent with the flux distribution of all known objects, including unidentified objects, for a reasonable set of parameters. The fraction of the populations predicted to be detectable in surveys of the Galactic plane with HESS and HAWC is then found to be in good agreement with their actual outcome, with a number of detectable halos ranging from 30 to 80% of the number of detectable PWNe. Prospects for CTA involve the detection of 250 − 300 sources in the Galactic Plane Survey, including 170 PWNe and up to 100 halos. The extent of diffusion suppression in halos has a limited impact on such prospects but its magnitude has a strong influence. The level of diffuse emission from unresolved populations in each survey is found to be dominated by halos and comparable to large-scale interstellar radiation powered by cosmic rays above 0.1–1 TeV.Conclusions.Pulsar halos are shown to be viable counterparts to a fraction of the currently unidentified sources if they develop around most middle-aged pulsars. Yet, if the phenomenon is rare, with an occurrence rate of 5 − 10% as suggested in a previous work from the local positron flux constraint, the total number of currently known TeV sources including unidentified ones cannot be accounted for in our model from young PWNe only. This calls for continued efforts to model pulsar-powered emission along the full evolutionary path, including the late stages past the young nebula phase.

Unexpected Dancing Partners: Tracing the Coherence between the Spin and Motion of Dark Matter Halos

A recent study conducted using CALIFA survey data has found that the orbital motions of neighbor galaxies are coherent with the spin direction of a target galaxy on scales of many megaparsecs. We study this so-called “large-scale coherence” phenomenon using N-body cosmological simulations. We confirm a strong coherence signal within 1 Mpc h −1 of a target galaxy, reaching out to 6 Mpc h −1. We divide the simulation halos into subsamples based on mass, spin, merger history, and local halo number density for both target and neighbor halos. We find a clear dependency on the mass of the target halo only. Another key parameter is the local number density of both target and neighbor halos, with high-density regions such as clusters and groups providing the strongest coherence signals, rather than filaments or lower-density regions. However we do not find a clear dependency on halo spin or time since last major merger. The most striking result we find is that the signal can be detected up to 15 Mpc h −1 from massive halos. These results provide valuable lessons on how observational studies could more clearly detect coherence, and we discuss the implications of our results for the origins of large-scale coherence.