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Material expelled from binary neutron star (BNS) mergers can harbour r-process nucleosynthesis and power a kilonova (KN), both intimately related to the astrophysical conditions of the ejection. In turn such conditions indirectly depend on the equation of state (EOS) describing matter inside the neutron star. Therefore, in principle the above observables can hold valuable information on nuclear matter, as the merger gravitational wave signal already does. In this work, we consider the outcome of a set of BNS merger simulations employing different finite-temperature nuclear EOSs. The latter are obtained from a Skyrme-type interaction model where nuclear properties, such as the incompressibility and the nucleon effective mass at saturation density, are systematically varied. We post-process the ejecta using a reaction network coupled with a semi-analytic KN model, to assess the sensitivity on the input EOS of the final yields and the KN light curves. Both of them are found to be non-trivially influenced by the EOS, with the overall outcome being dominated by the heterogeneous outflows from the remnant disc, hosting a variable degree of neutron-rich material. The dynamical ejecta can be more directly related to the EOS parameters considered; however, we find their role in the yields production and the KN emission too entangled with the other ejecta components, in order to infer solid correlations. This result highlights the strong degeneracy that intervenes between the merger outcome and the behaviour of the intrinsic nuclear matter, and places itself as a limit to the employment of EOS-constraining approaches of such kind. [ABSTRACT FROM AUTHOR]

We compute the structure of a Newtonian, multi-ion radiation-mediated shock (RMS) for different compositions anticipated in various stellar explosions. We use a multifluid RMS model that incorporates electrostatic coupling between the different plasma constituents as well as Coulomb friction in a self-consistent manner, and approximates the effect of pair creation and the presence of free neutrons in the shock upstream on the shock structure. We find that under certain conditions a significant velocity separation is developed between different ions in the shock downstream and demonstrate that in fast enough shocks ion–ion collisions may trigger fusion and fission events at a relatively high rate. Our analysis ignores anomalous coupling through plasma microturbulence, which might reduce the velocity spread downstream below the activation energy for nuclear reactions. A rough estimate of the scale separation in RMS suggests that for shocks propagating in binary neutron star (BNS) merger ejecta, the anomalous coupling length may exceed the radiation length, allowing a considerable composition change behind the shock via inelastic collisions of |$\alpha$| particles with heavy elements at shock velocities |$\beta _\mathrm{ u}\gtrsim 0.25$|⁠. A sufficient abundance of free neutrons in the shock upstream, as expected during the first second after the merger, is also expected to alter the ejecta composition through neutron capture downstream. The resultant change in the composition profile may affect the properties of the early kilonova emission. The generation of microturbulence due to velocity separation can also give rise to particle acceleration that might alter the breakout signal in supernovae and other systems. [ABSTRACT FROM AUTHOR]

Global concern about the accumulation of heavy metal(loid)s (HMs) in agricultural soils and its subsequent effects on human health has increased. In particular, arsenic is a metalloid with known toxic and carcinogenic properties. This study was conducted with the aim of investigating arsenic contamination in agricultural soils of Hashtroud County, while assessing the levels of some heavy metals and the associated ecological and health risks due to possible exposure to these contaminants. The average concentrations of zinc (Zn), lead (Pb), nickel (Ni), copper (Cu), chromium (Cr), arsenic (As), cobalt (Co), and cadmium (Cd) (respectively, 72, 42, 41, 40, 24, 16, 13, and 0.6 (mg/kg)) did not exceed the national guideline value except for As. Arsenic was the element most enriched in the study area (enrichment factor (EF): 3.3). In general, the soil samples showed moderate ecological risk (RI = 174.17). The non-carcinogenic risks of HMs were acceptable, while the carcinogenic risk value (LCR) for As exceeded the threshold of 1 × 10−4 at 10% of the samples. Source attribution of HMs using the positive matrix factorization (PMF) model showed that Zn and Pb were mainly due to vehicle emissions. Agricultural activities and atmospheric deposition were the predominant sources of Cu and Zn; As and Cd were from natural sources; and Ni, Cr, and Co were from mixed sources of pedogenic factors and agricultural activities. To conclude, in study area, addressing arsenic as a main concern is crucial due to its ecological and health risks. The agro-geogenic source with a contribution rate of 64.87%, was identified as the primary origin of the elements. Further research is needed to investigate the bioaccumulation and bioavailability of HMs in the soil-crop system. [ABSTRACT FROM AUTHOR]

The progenitor system(s) as well as the explosion mechanism(s) of thermonuclear (Type Ia) supernovae are long-standing issues in astrophysics. Here we present ejecta masses and other physical parameters for 28 recent Type Ia supernovae inferred from multiband photometric and optical spectroscopic data. Our results confirm that the majority of SNe Ia show observable ejecta masses below the Chandrasekhar-limit (having a mean M ej ≈ 1.1 ± 0.3 M ⊙), consistent with the predictions of recent sub- M Ch explosion models. They are compatible with models assuming either single- or double-degenerate progenitor configurations. We also recover a sub-sample of supernovae within 1.2 M ⊙ < M ej < 1.5 M ⊙ that are consistent with near-Chandrasekhar explosions. Taking into account the uncertainties of the inferred ejecta masses, about half of our SNe are compatible with both explosion models. We compare our results with those in previous studies, and discuss the caveats and concerns regarding the applied methodology. [ABSTRACT FROM AUTHOR]

Strong metallicity-dependent winds dominate the evolution of core He-burning, classical Wolf–Rayet (cWR) stars, which eject both H and He-fusion products such as |$^{14}$| N, |$^{12}$| C, |$^{16}$| O, |$^{19}$| F, |$^{22}$| Ne, and |$^{23}$| Na during their evolution. The chemical enrichment from cWRs can be significant. cWR stars are also key sources for neutron production relevant for the weak s-process. We calculate stellar models of cWRs at solar metallicity for a range of initial Helium star masses (12–50  |$\rm M_{\odot }$|⁠), adopting recent hydrodynamical wind rates. Stellar wind yields are provided for the entire post-main sequence evolution until core O-exhaustion. While literature has previously considered cWRs as a viable source of the radioisotope |$^{26}$| Al, we confirm that negligible |$^{26}$| Al is ejected by cWRs since it has decayed to |$^{26}$| Mg or proton-captured to |$^{27}$| Al. However, in Paper I, we showed that very massive stars eject substantial quantities of |$^{26}$| Al, among other elements including N, Ne, and Na, already from the zero-age-main-sequence. Here, we examine the production of |$^{19}$| F and find that even with lower mass-loss rates than previous studies, our cWR models still eject substantial amounts of |$^{19}$| F. We provide central neutron densities (N |$_{n}$|⁠) of a 30  |$\rm M_{\odot }$| cWR compared with a 32  |$\rm M_{\odot }$| post-VMS WR and confirm that during core He-burning, cWRs produce a significant number of neutrons for the weak s-process via the |$^{22}$| Ne(⁠|$\alpha$|⁠ ,n) |$^{25}$| Mg reaction. Finally, we compare our cWR models with observed [Ne/He], [C/He], and [O/He] ratios of Galactic WC and WO stars. [ABSTRACT FROM AUTHOR]

One-dimensional (1D) stellar evolution models are widely used across various astrophysical fields, however they are still dominated by important uncertainties that deeply affect their predictive power. Among those, the merging of independent convective regions is a poorly understood phenomenon predicted by some 1D models but whose occurrence and impact in real stars remain very uncertain. Being an intrinsically multi-D phenomenon, it is challenging to predict the exact behaviour of shell mergers with 1D models. In this work, we conduct a detailed investigation of a multiple shell merging event in a 20 M |$_\odot$| star using 3D hydrodynamic simulations. Making use of the active tracers for composition and the nuclear network included in the 3D model, we study the merging not only from a dynamical standpoint but also considering its nucleosynthesis and energy generation. Our simulations confirm the occurrence of the merging also in 3D, but reveal significant differences from the 1D case. Specifically, we identify entrainment and the erosion of stable regions as the main mechanisms that drive the merging, we predict much faster convective velocities compared to the mixing-length theory velocities, and observe multiple burning phases within the same merged shell, with important effects for the chemical composition of the star, which presents a strongly asymmetric (dipolar) distribution. We expect that these differences will have important effects on the final structure of massive stars and thus their final collapse dynamics and possible supernova explosion, subsequently affecting the resulting nucleosynthesis and remnant. [ABSTRACT FROM AUTHOR]

The ability of Big Bang Nucleosynthesis theory to accurately predict the primordial abundances of helium and deuterium, as well as the baryon content of the Universe, is considered one of the most significant achievements in modern physics. In the present study, we consider two highly motivated hybrid |$f(T)$| models and constrain them using the observations from the Big Bang Nucleosynthesis era. In addition, using late-time observations of Cosmic Chronometers and Gamma-Ray Bursts, the ranges of the model parameters are confined which are in good agreement with early time bounds. Subsequently, the common ranges obtained from the analysis for early and late time are summarized. Further, we verify the intermediating epochs by investigating the profiles of cosmographic parameters using the model parameter values from the common range. From this study, we find the considered teleparallel models are viable candidates to explain the primordial-intermediating-present epochs. [ABSTRACT FROM AUTHOR]

The source of the Galactic lithium (Li) has long been a puzzle. With the discovery of Li in novae, extensive research has been conducted. However, there still exists a significant disparity between the observed abundance of Li in novae and the existing theoretical predictions. Using the Modules for Experiments in Stellar Astrophysics, we simulate the evolution of novae with element diffusion and appropriately increase the amount of 3He in the mixtures. Element diffusion enhances the transport efficiency between the nuclear reaction zone and the convective region on the surface of the white dwarf (WD) during nova eruptions, which results in more 7Be being transmitted to the WD surface and ultimately ejected. Compared to the previous predictions, the abundance of 7Be in novae simulated in our model significantly increases. The result is able to explain almost all observed novae. Using the method of population synthesis, we calculate Li yield in the Galaxy. We find that the Galactic occurrence rate of novae is about 130 yr−1, and about 110 M ⊙ Li produced by nova eruption is ejected into the interstellar medium (ISM). About 73% of Li in the Galactic ISM originates from novae and approximately 15%–20% of the entire Galaxy. This means that novae are the important source of Li in the Galaxy. [ABSTRACT FROM AUTHOR]

Free neutron decay is the prototype for nuclear beta decay and other semileptonic weak particle decays. It provides important insights into the symmetries of the weak nuclear force. Neutron decay is important for understanding the formation and abundance of light elements in the early universe. The two main experimental approaches for measuring the neutron lifetime, the beam method and the ultracold neutron storage method, have produced results that currently differ by 9.8 ± 2.0 s. While this discrepancy probably has an experimental origin, a more exciting prospect is that it may be explained by new physics, with possible connections to dark matter. The experimental status of the neutron lifetime is briefly reviewed, with an emphasis on its implications for cosmology, astrophysics, and dark matter. [ABSTRACT FROM AUTHOR]

We review the evolution of our understanding of the planetary nebulae phenomenon and their place in the scheme of stellar evolution. The historical steps leading to our current understanding of central star evolution and nebular formation are discussed. Recent optical imaging, X-ray, ultraviolet, infrared, millimeter wave, and radio observations have led to a much more complex picture of the structure of planetary nebulae. The optically bright regions have multiple shell structures (rims, shells, crowns, and haloes), which can be understood within the interacting winds framework. However, the physical mechanism responsible for bipolar and multipolar structures that emerged during the proto-planetary nebulae phase is yet to be identified. Our morphological classifications of planetary nebulae are hampered by the effects of sensitivity, orientation, and field-of-view coverage, and the fraction of bipolar or multipolar nebulae may be much higher than commonly assumed. The optically bright bipolar lobes may represent low-density, ionization-bounded cavities carved out of a neutral envelope by collimated fast winds. Planetary nebulae are sites of active synthesis of complex organic compounds, suggesting that planetary nebulae play a major role in the chemical enrichment of the Galaxy. Possible avenues of future advancement are discussed. [ABSTRACT FROM AUTHOR]

Source water quality is a key determinant of drinking water quality. The recast European Union 2020/2184 Drinking Water Directive (DWD) introduced the obligation for comprehensive risk assessment in drinking water supplies, including hazard assessment of the water source. The DWD also requires further elements of natural origin to be monitored, including U, Ca, Mg and K. The current study is the first comprehensive assessment of 15 natural elements (B, Ba, Be, Ca, Co, K, Li, Mg, Mo, Na, Se, Sr, Ti, U and V) in 1155 (82%) Hungarian drinking water sources, including surface water, bank filtered and groundwater sources. Parameters posing a risk to health (Se, V and U) were typically below the limit of quantification (LOQ), but higher concentrations (max. 7.0, 17 and 41 µg/L, respectively) may occur in confined locations. U exceeded the DWD parametric value in one water supply. Mg and Ca in the majority of the water supplies and Li in a small geographic area reached the concentration range assumed to be protective to health. Water sources were grouped in six clusters based on their elemental distribution, some of them also showing clear geographical patterns. Surface and groundwater sources were not differentiated by composition, with the exception of karstic waters (dominated by Ca and Mg). None of the investigated parameters are expected to be a source of public health concern on a national level, but local occurrences of U and Se should be investigated and managed on a case-by-case basis. [ABSTRACT FROM AUTHOR]

We report isotope data for C, N, Al, Si, and S of 33 presolar SiC and Si3N4 grains (0.3–1.6  |$\mu$| m) of Type X, C, D, and N from the Murchison CM2 meteorite of likely core-collapse supernova (CCSN) origin which we discuss together with data of six SiC X grains from an earlier study. The isotope data are discussed in the context of hydrogen ingestion supernova (SN) models. We have modified previously used ad-hoc mixing schemes in that we considered (i) heterogeneous H ingestion into the He shell of the pre-SN star, (ii) a variable C-N fractionation for the condensation of SiC grains in the SN ejecta, and (iii) smaller mass units for better fine-tuning. With our modified ad-hoc mixing approach over small scales (0.2–0.4 M⊙), with major contributions from the O-rich O/nova zone, we find remarkably good fits (within a few per cent) for 12C/13C, 26Al/27Al, and 29Si/28Si ratios. The 14N/15N ratio of SiC grains can be well matched if variable C-N fractionation is considered. However, the Si3N4 isotope data point to overproduction of 15N in hydrogen ingestion CCSN models and lower C-N fractionation during SiC condensation than applied here. Our ad-hoc mixing approach based on current CCSN models suggests that the O-rich O/nova zone, which uniquely combines explosive H- and He-burning signatures, is favourable for SiC and Si3N4 formation. The effective range of C/O abundance variations in the He shell triggered by H ingestion events in the massive star progenitor is currently not well constrained and needs further investigation. [ABSTRACT FROM AUTHOR]

This article discusses the field of nuclear physics and its various applications and frontiers. It highlights the importance of collaboration between theory and experiment in making breakthroughs in the field. The article includes contributions from researchers in different subfields of nuclear physics, such as nuclear structure, reactions, dynamics, hadron physics, nuclear astrophysics, and neutrino physics. It also discusses the use of different methodologies, including Monte Carlo approaches and ab initio methods. The article concludes by mentioning upcoming facilities and future opportunities for nuclear physics research. [Extracted from the article]

The pivotal role of nuclear physics in nucleosynthesis processes is being investigated, in particular the intricate influence of photon strength functions (PSFs) and nuclear level densities (NLDs) on shaping the outcomes of the i-, r- and p-processes. Exploring diverse NLD and PSF model combinations uncovers large uncertainties for (p, γ), (n, γ) and (α , γ) rates across many regions of the nuclear chart. These lead to potentially significant abundance variations of the nucleosynthesis processes and highlight the importance of accurate experimental nuclear data. Theoretical insights and advanced experimental techniques lay the ground work for profound understanding that can be gained of nucleosynthesis mechanisms and the origin of the elements. Recent results further underscore the effect of PSF and NLD data and its contribution to understanding abundance distributions and refining knowledge of the intricate nucleosynthesis processes. This article is part of the theme issue 'The liminal position of Nuclear Physics: from hadrons to neutron stars'. [ABSTRACT FROM AUTHOR]

Well-developed α clusters are known to exist in light N=Z nuclei, and their properties are reasonably well described with modern nuclear structure theories. However, 'modestly' developed clusters in medium to heavy nuclei remain little understood, both theoretically and experimentally. Extension of the focus to include modestly developed clusters leads us to a concept of 'generalized clusters' and 'cluster ubiquitousness'. The former includes clusters more weakly bound than an α cluster, such as deuteron, triton and He3 , and even clusters partially broken owing to nuclear medium effects. The latter means the existence of clusters in any nuclei, where cluster development was not previously discussed. Effects of the tensor and the spin–orbit interactions on the coexistence of clusters with independent nucleons are discussed using recent nuclear theoretical models. A mixture of the clusters with shell-like components plays an essential role in the synthesis of elements in the universe and the origin of life, together with an α decay. It is also pointed out that clustering in heavy nuclei may accelerate fission and fusion processes. Future experimental plans using cluster knockout reactions, which have the potential to extract information of 'generalized clusters' in a variety of nuclei including stable and unstable nuclei, are also discussed. This article is part of the theme issue 'The liminal position of Nuclear Physics: from hadrons to neutron stars'. [ABSTRACT FROM AUTHOR]

The present study evaluated an integrated biomonitoring approach based on three different bioindicators: tree rings, lichens, and beetles in a complex environment (urban-industrial-forest). In Central Italy, four sampling sites were selected to assess the anthropogenic impact of cement plants taking into account (1) long-term exposure (1988–2020) through the analysis of trace elements in tree rings of Quercus pubescens; (2) medium-term exposure (2020–2021) through the analysis of trace elements in thalli (outermost portions) of the lichen Xanthoria parietina; (3) short-term exposure in spring 2021 through the bioaccumulation and evaluation of sample vitality in transplants of the lichen Evernia prunastri and a periodic survey of entomological biodiversity carried out during spring and summer 2021. Trace elements of industrial origin were found in tree rings, with different levels of accumulation between 1988 and 2020 and a maximum in 2012. Native thalli of the lichen X. parietina showed an overall low bioaccumulation of trace elements except for Cr, probably reflecting the influence of national lockdown measures. The transplants of E. prunastri showed a weak stress response in the industrial and urban sites, but not in the forest, and identified Tl and V as the main elements contributing to atmospheric contamination, with peaks at the industrial sites. Concerning the beetles, a significantly lower number of species was found at the Semonte industrial site. [ABSTRACT FROM AUTHOR]

Context. The production of neutron-rich elements at neutron densities intermediate to those of the s- and r-processes, the so-called i-process, has been identified as possibly being responsible for the observed abundance pattern found in certain carbon-enhanced metal-poor (CEMP) stars. The production site may be low-metallicity stars on the asymptotic giant branch (AGB) where the physical processes during the thermal pulses are not well known. Aims. We investigate the impact of overshoot from various convective boundaries during the AGB phase on proton ingestion events (PIEs) and the neutron densities as a necessary precondition for the i-process as well as on the structure and continued evolution of the models. Methods. We therefore analyzed models of a 1.2 M⊙, Z = 5 × 10−5 star. A fiducial model without overshoot on the AGB (overshoot was applied during the pre-AGB evolution) serves as a reference. The same model was then run with various overshoot values and the resulting models were compared to one another. Light element nucleosynthesis is also discussed. Additionally, we introduce a new timescale argument to predict PIE occurrence to discriminate between a physical and a numerical reason for a nonoccurrence. A comparison to observations as well as previous studies was conducted before finally presenting the most promising choice of overshoot parameters for the occurrence of the i-process in low-mass, low-metallicity models. Results. The fiducial model reveals high neutron densities and a persistent split of the pulse-driven convection zone (PDCZ). Overshoot from the PDCZ results in either temporary or permanent remerging of the split PDCZ, influencing the star's structure and evolution. While both overshoot and non-overshoot models exhibit PIEs generating neutron densities suitable for the i-process, they lead to varied C/O and N/O ratios and notable Li enhancements. Comparison with previous studies and observations of CEMP-r/s stars suggests that while surface enhancements in our models may be exaggerated, abundance ratios align well. Though, for high values of overshoot from the PDCZ the agreement becomes worse. [ABSTRACT FROM AUTHOR]

Context. An accurate 28P(p, γ)29S reaction rate is crucial to defining the nucleosynthesis products of explosive hydrogen burning in ONe novae. Using the recently released nuclear mass of 29S, together with a shell model and a direct capture calculation, we reanalyzed the 28P(p, γ)29S thermonuclear reaction rate and its astrophysical implication. Aims. We focus on improving the astrophysical rate for 28P(p, γ)29S based on the newest nuclear mass data. Our goal is to explore the impact of the new rate and associated uncertainties on the nova nucleosynthesis. Methods. We evaluated this reaction rate via the sum of the isolated resonance contribution instead of the previously used Hauser-Feshbach statistical model. The corresponding rate uncertainty at different energies was derived using a Monte Carlo method. Nova nucleosynthesis is computed with the 1D hydrodynamic code SHIVA. Results. The contribution from the capture on the first excited state at 105.64 keV in 28P is taken into account for the first time. We find that the capture rate on the first excited state in28 P is up to more than 12 times larger than the ground-state capture rate in the temperature region of 2.5 × 107 K to 4 × 108 K, resulting in the total 28P(p, γ)29S reaction rate being enhanced by a factor of up to 1.4 at ~1 × 109 K. In addition, the rate uncertainty has been quantified for the first time. It is found that the new rate is smaller than the previous statistical model rates, but it still agrees with them within uncertainties for nova temperatures. The statistical model appears to be roughly valid for the rate estimation of this reaction in the nova nucleosynthesis scenario. Using the 1D hydrodynamic code SHIVA, we performed the nucleosynthesis calculations in a nova explosion to investigate the impact of the new rates of 28P(p, γ)29S. Our calculations show that the nova abundance pattern is only marginally affected if we use our new rates with respect to the same simulations but statistical model rates. Finally, the isotopes whose abundance is most influenced by the present 28P(p, γ)29S uncertainty are 28Si, 33,34S, 35,37Cl, and 36Ar, with relative abundance changes at the level of only 3% to 4%. [ABSTRACT FROM AUTHOR]

Context. Carbon is the fourth most abundant element in the universe and its distribution is critical to understanding stellar evolution and nucleosynthesis. In optical studies of ionized nebulae, the only way to determine the C/H abundance is by using faint C II recombination lines (RLs). However, these lines give systematically higher abundances than their collisionally excited counterparts, observable at ultraviolet (UV) wavelengths. Therefore, a proper understanding of the excitation mechanisms of the faint permitted lines is crucial for addressing this long-standing abundance discrepancy (AD) problem. Aims. In this study, we investigate the excitation mechanisms of C II lines λλ3918, 3920, 4267, 5342, 6151, 6462, 7231, 7236, 7237, and 9903. Methods. We use the DEep Spectra of Ionized REgions Database (DESIRED) that contains spectra of H II regions, planetary nebulae and other objects to analyze the fluorescence contributions to these lines and the accuracy of the atomic recombination data used to model the C+ ion. Results. We find that C IIλλ4267, 5342, 6151, 6462, and 9903 arise exclusively from recombinations with no fluorescent contributions. In addition, the recombination theory for these lines is consistent with the observations. Our findings show that the AD problem for C2+ is not due to fluorescence in the widely used C II lines or errors in their atomic parameters, but to other phenomena such as temperature variations or chemical inhomogeneities. On the other hand, C IIλλ3918, 3920, 6578, 7231, 7236, 7237 have important fluorescent contributions, which are inadvisable for tracing the C2+ abundances. We also discuss the effects of possible inconsistencies in the atomic effective recombination coefficients of C IIλλ6578, 7231, 7236, and 7237. [ABSTRACT FROM AUTHOR]

The treatment of convection remains a major weakness in the modelling of stellar evolution with one-dimensional (1D) codes. The ever-increasing computing power makes now possible to simulate in three-dimensional (3D) part of a star for a fraction of its life, allowing us to study the full complexity of convective zones with hydrodynamics codes. Here, we performed state-of-the-art hydrodynamics simulations of turbulence in a neon-burning convective zone, during the late stage of the life of a massive star. We produced a set of simulations varying the resolution of the computing domain (from 1283 to 10243 cells) and the efficiency of the nuclear reactions (by boosting the energy generation rate from nominal to a factor of 1000). We analysed our results by the mean of Fourier transform of the velocity field, and mean-field decomposition of the various transport equations. Our results are in line with previous studies, showing that the behaviour of the bulk of the convective zone is already well captured at a relatively low resolution (2563), while the details of the convective boundaries require higher resolutions. The different boosting factors used show how various quantities (velocity, buoyancy, abundances, and abundance variances) depend on the energy generation rate. We found that for low boosting factors, convective zones are well mixed, validating the approach usually used in 1D stellar evolution codes. However, when nuclear burning and turbulent transport occur on the same time-scale, a more sophisticated treatment would be needed. This is typically the case when shell mergers occur. [ABSTRACT FROM AUTHOR]

Primordial Black Holes (PBHs) could dominate in the early universe and, evaporating before Big bang Nucleosynthesis, provide new freeze in mechanism of dark matter (DM) production. The proposed scenario is considered for two possible mechanisms of PBH formation and the corresponding continuous PBH mass spectra so that the effect of non-single PBH mass spectrum is taken into account in the results of PBH evaporation, by which PBH dominance in the early universe ends. We specify the conditions under which the proposed scenario can explain production of dark matter in very early universe. [ABSTRACT FROM AUTHOR]

We here focus on the behavior of supernovae that technically explode in 1D (spherical symmetry). When simulated in 3D, however, the outcomes of representative progenitors of this class are quite different in almost all relevant quantities. In 3D, the explosion energies can be 2 to 10 times higher, and there are correspondingly large differences in the 56Ni yields. These differences between the 3D and 1D simulations reflect in part the relative delay to explosion of the latter and in the former the presence of protoneutron star convection that boosts the driving neutrino luminosities by as much as ∼50% at later times. In addition, we find that the ejecta in 3D models are more neutron-rich, resulting in significant weak r -process and 48Ca yields. Furthermore, we find that in 3D the core is an interesting, though subdominant, source of acoustic power. In summary, we find that though a model might be found theoretically to explode in 1D, one must perform supernova simulations in 3D to capture most of the associated observables. The differences between 1D and 3D models are just too large to ignore. [ABSTRACT FROM AUTHOR]

Fluorine is one of the most interesting elements in nuclear astrophysics. Its abundance can provide important hints to constrain the stellar models since fluorine production and destruction are strictly connected to the physical conditions inside the stars. The F 19 (p,α)16O reaction is one of the fluorine burning processes and the correction evaluation of its reaction rate is of pivotal importance to evaluate the fluorine abundance. Moreover, the F 19 (p,α)16O reaction rate can have an impact for the production of calcium in the first-generation of Population III stars. Here, we present the AsFiN collaboration efforts to the study of the F 19 (p, α)16O reaction by means of direct and indirect measurements. On the direct measurements side, an experimental campaign aimed to the measurement of the F 19 (p, α 0 , π )16O reaction is ongoing, taking advantage of the new versatile arrays of silicon strip detectors, LHASA and ELISSA. Moreover, the Trojan Horse Method (THM) was used to determine the F 19 (p, α 0 )16O reaction S(E)-factor in the energy range of astrophysical interest ( E c m ≈ 0–1 MeV), showing, for the first time, the presence of resonant structures within the astrophysical energy range. THM has been also applied for the study of the F 19 (p, α π )16O reaction; data analysis is ongoing. [ABSTRACT FROM AUTHOR]

Qalaee is Unani name of tin (stannum), which is a metallic element, belongs to group 14 of periodic table. Atomic number of tin is 50 and its atomic mass is 119. Qalaee (Tin) consist two types of compounds, inorganic tin compounds and organic tin compounds. Several toxic and adverse effect studies of Qalaee (stannum) have been reported such as, Respiratory Effects, Gastrointestinal Effects, Haematological Effects, Renal Effects, Dermal Effects, Ocular Effects, Immunological and Lymph reticular Effects, Neurological Effects, Cardiovascular Effects, Body weight effect and reproductive effects. Some studies on different pharmacological activities of tin also reported like, antibacterial activity, anticancer activity and anti-parasitic activity. In traditional system of medicine Qalaee is used in the form of Kusta or Bhasm for various disorders such as spermatorrhoea, excessive nocturnal emission, premature ejaculation and Syphilis etc. Its important Unani formulation is Kusta qalaee. [ABSTRACT FROM AUTHOR]

Glyptothorax pongoensis, sp. n. is described from the Yongmon River in Nagaland, India. The new species can be distinguished from its congeners in the Indian subcontinent by the following combination of characters: an ovate-shaped thoracic adhesive apparatus with skin ridges present over the entire apparatus, including the subulate-shaped median depression; presence of plicae on the ventral surface of the pectoral fin spine and the first ray of the pelvic fin; W-shaped anterior nuchal plate element; dorsal-fin origin nearer to the snout tip than to the origin of the adipose fin; posterior margin of dorsal spine rugose with 4–5 ridges, tuberculate skin, and nasal barbel not reaching eye when adpressed. [ABSTRACT FROM AUTHOR]

Nuclear reactions are key to our understanding of stellar evolution, particularly the |$^{12}{\rm C}(\alpha ,\gamma)^{16}{\rm O}\,$| rate, which is known to significantly influence the lower and upper ends of the black hole (BH) mass distribution due to pair-instability supernovae (PISNe). However, these reaction rates have not been sufficiently determined. We use the mesa stellar evolution code to explore the impact of uncertainty in the |$^{12}{\rm C}(\alpha ,\gamma)^{16}{\rm O}\,$| rate on PISN explosions, focusing on nucleosynthesis and explosion energy by considering the high resolution of the initial mass. Our findings show that the mass of synthesized radioactive nickel (56Ni) and the explosion energy increase with |$^{12}{\rm C}(\alpha ,\gamma)^{16}{\rm O}\,$| rate for the same initial mass, except in the high-mass edge region. With a high (about twice the starlib standard value) rate, the maximum amount of nickel produced falls below 70 M⊙, while with a low rate (about half of the standard value) it increases up to 83.9 M⊙. These results highlight that carbon 'preheating' plays a crucial role in PISNe by determining core concentration when a star initiates expansion. Our results also suggest that the onset of the expansion, which means the end of compression, competes with collapse caused by helium photodisintegration, and the maximum mass that can lead to an explosion depends on the |$^{12}{\rm C}(\alpha ,\gamma)^{16}{\rm O}\,$| reaction rate. [ABSTRACT FROM AUTHOR]

We investigate early (t < 1 day) kilonova from a neutron star merger by deriving atomic opacities for all the elements from La to Ra (Z = 57–88) ionized to the states V–XI. The opacities at high temperatures for the elements with open f -shells (e.g., lanthanides) are exceptionally high, reaching κ exp ∼ 3 × 10 3 cm 2 g − 1 at λ ≤ 1000 Å at T ∼ 70,000 K, whereas the opacities at the same temperature and wavelengths for the elements with open d -, p -, and s -shells reach κ exp ∼ 1 , 0.1, and 0.01 cm2 g−1, respectively. Using the new opacity data set, we derive early kilonovae for various compositions and density structures expected for neutron star merger ejecta. The bolometric luminosity of the lanthanide-rich ejecta shows distinct signatures and is fainter than that of the lanthanide-free ejecta. Early luminosity is suppressed by the presence of a thin outer layer, agreeing with the results of Kasen et al. and Banerjee et al. The early brightness in the Swift UVOT filters and in the optical g, r, i, and z filters for a source at 100 Mpc are about ∼22–19.5 and ∼21–20 mag, respectively, at t ∼ 0.1 day. Such kilonovae are ideal targets for the upcoming UV satellites, such as ULTRASAT, UVEX, and DORADO, and the upcoming surveys, e.g., the Vera Rubin Observatory. We suggest that the gray opacities that reproduce the bolometric light curves with and without lanthanides are ∼1–10 and ∼0.8 cm2 g−1. [ABSTRACT FROM AUTHOR]

A simple analytic description is provided of the rate of energy deposition by β-decay electrons in the homologously expanding radioactive plasma ejected in neutron star mergers, valid for a wide range of ejecta parameters – initial entropy, electron fraction { s 0, Ye }, and scaled (time-independent) density ρ t 3. The formulae are derived using detailed numerical calculations following the time-dependent composition and β-decay emission spectra (including the effect of delayed deposition). The deposition efficiency depends mainly on ρ t 3 and only weakly on { s 0, Ye }. The time te at which the ratio between the rates of electron energy deposition and energy production drops to 1 − e −1, is given by |$t_e=t_{0e}\Big (\frac{\rho t^3}{0.5(\rho t^3)_0}\Big)^a$|⁠ , where |$(\rho t^3)_0=\frac{0.05\, {\rm M}_{\odot }}{4\pi (0.2c)^3}$|⁠ , t 0 e (s 0, Ye) ≈ 17 d, and 0.4 ≤ a (s 0, Ye) ≤ 0.5. The fractional uncertainty in te due to nuclear physics uncertainties is |$\approx 10~{{\ \rm per\ cent}}$|⁠. The result a ≤ 0.5 reflects the fact that the characteristic β-decay electron energies do not decrease with time (largely due to 'inverted decay chains' in which a slowly decaying isotope decays to a rapidly decaying isotope with higher end-point energy). We provide an analytic approximation for the time-dependent electron energy deposition rate, reproducing the numerical results to better than 50 per cent (typically |$\lt 30~{{\ \rm per\ cent}}$|⁠ , well within the energy production rate uncertainty due to nuclear physics uncertainties) over a 3–4 orders-of-magnitude deposition rate decrease with time. Our results may be easily incorporated in calculations of kilonovae light curves (with general density and composition structures), eliminating the need to numerically follow the time-dependent electron spectra. Identifying te , e.g. in the bolometric light curve, will constrain the ejecta density distribution. [ABSTRACT FROM AUTHOR]

Neutron star mergers are astrophysical "gold mines," synthesizing over half of the elements heavier than iron through rapid neutron capture nucleosynthesis. The observation of the binary neutron star merger GW170817, detected both in gravitational waves and electromagnetic radiation, marked a breakthrough. One electromagnetic component of this event, the gamma ray burst GRB 170817A, has an unresolved aspect: the characteristics of its prompt gamma-ray emission spectrum. In this work, we investigate that gamma-ray spectra in such GRBs may be influenced by de-excitations from isomeric transitions. Our study begins with a review of current knowledge on GRB structure and of r-process nucleosynthesis in neutron star collisions, focusing on the role of nuclear isomers in these settings. We then test our hypothesis by developing criteria to select representative isomers, based on known solar element abundances, for modeling GRB spectral characteristics. We integrate these criteria into an interactive web page, facilitating the construction and analysis of relevant gamma-ray spectra from isomeric transitions. Our analysis reveals that three isomers -- 90Zr, 207Pb, and 89Y -- stand out for their potential to impact the prompt GRB spectrum due to their specific properties. This information allows us to incorporate nuclear isomer data into astrophysical simulations and calculate isomeric abundances generated by astrophysical r-processes in neutron star mergers and their imprint on the detected signal. [ABSTRACT FROM AUTHOR]

We present a detailed chemical abundance and kinematic analysis of six extremely metal-poor (−4.2 ≤ [Fe/H] ≤−2.9) halo stars with very low neutron-capture abundances ([Sr/H] and [Ba/H]) based on high-resolution Magellan/MIKE spectra. Three of our stars have [Sr/Ba] and [Sr/H] ratios that resemble those of metal-poor stars in ultra-faint dwarf galaxies (UFDs). Since early UFDs may be the building blocks of the Milky Way, extremely metal-poor halo stars with low, UFD-like Sr and Ba abundances may thus be ancient stars from the earliest small galactic systems that were accreted by the proto-Milky Way. We label these objects as Small Accreted Stellar System (SASS) stars, and we find an additional 61 similar ones in the literature. A kinematic analysis of our sample and literature stars reveals them to be fast-moving halo objects, all with retrograde motion, indicating an accretion origin. Because SASS stars are much brighter than typical UFD stars, identifying them offers promising ways towards detailed studies of early star formation environments. From the chemical abundances of SASS stars, it appears that the earliest accreted systems were likely enriched by a few supernovae whose light element yields varied from system to system. Neutron-capture elements were sparsely produced and/or diluted, with r -process nucleosynthesis playing a role. These insights offer a glimpse into the early formation of the Galaxy. Using neutron-capture elements as a distinguishing criterion for early formation, we have access to a unique metal-poor population that consists of the oldest stars in the universe. [ABSTRACT FROM AUTHOR]

This is a summary of the main results within the Scale-Invariant Vacuum (SIV) paradigm based on Weyl integrable geometry. We also review the mathematical framework and utilize alternative derivations of the key equations based on the reparametrization invariance as well. The main results discussed are related to the early universe; that is, applications to inflation, Big Bang Nucleosynthesis, and the growth of the density fluctuations within the SIV. Some of the key SIV results for the early universe are a natural exit from inflation within the SIV in a later time t exit with value related to the parameters of the inflationary potential along with the possibility for the density fluctuations to grow sufficiently fast within the SIV without the need for dark matter to seed the growth of structure in the universe. In the late-time universe, the applications of the SIV paradigm are related to scale-invariant dynamics of galaxies, MOND, dark matter, and dwarf spheroidals, where one can find MOND to be a peculiar case of the SIV theory. Finally, within the recent time epoch, we highlight that some of the change in the length-of-the-day (LOD), about 0.92 cm/yr, can be accounted for by SIV effects in the Earth–Moon system. [ABSTRACT FROM AUTHOR]

Soil is a component of the environment. An environmental policy should identify the sources of trace metals in the soil and their effects on people and living beings. The concentrations of 29 surface soil samples (0–25 cm) were determined using the methods EPA 3050B. The data were analyzed using simple and robust statistical analysis that allowed for determining geochemical baseline values. Principal component and correlation analyses were performed, which, together with a spatial analysis, allowed us to distinguish between geogenic and anthropogenic sources. The degree of soil contamination was evaluated using different ecological indices, and the health risks to children and adults were calculated using formulas proposed by the United States Environmental Protection Agency (USEPA). The median concentrations of the analyzed elements correspond to Al 17,666 (mg/kg), As 8.7 (mg/kg), Ba 61.4 (mg/kg), Cd 0.17 (mg/kg), Cr 11.3 (mg/kg), Cu 20.5 (mg/kg), Fe 25,953 (mg/kg), Hg 0.06 (mg/kg), Mn 499 (mg/kg), Ni 20.8 (mg/kg), Pb 15.9 (mg/kg), and Zn 60.6 (mg/kg). In the principal component analysis, four factors were identified that explain 70.3% of the variability of the elements, which, together with the correlation analysis, suggest that the origin of the elements is mainly geogenic with some possible anthropic contributions. The elements analyzed in the soil with moderate contamination correspond to As, Cd, and Pb, in addition, As is the only element that indicated a value above the limit for carcinogenic risk in children. The estimated geochemical baseline values correspond to Al 34,734 (mg/kg), As 15.3 (mg/kg), Ba 113 (mg/kg), Cd 0.41 (mg/kg), Cr 33.8 (mg/kg), Cu 42.9 (mg/kg), Fe 46,181 (mg/kg), Hg 0.12 (mg/kg), Mn 1015 (mg/kg), Ni 42.2 (mg/kg), Pb 21.6 (mg/kg), and Zn 121 (mg/kg). 89.7% of the total samples are at a low level of contamination. The carcinogenic risk due to As in children represents 3.4% of the total samples, so it is considered insignificant. [ABSTRACT FROM AUTHOR]

Dirinaria picta is a lichen species known for its tolerance to air pollution and its ability to accumulate pollutants in its thallus, making it a suitable bioindicator in urban areas. This study aims to assess the response of lichens to air pollution by examining their morphological characteristics, analyzing the presence of magnetic grains, and identifying the origin of elements in their tissues. Samples were collected from three locations in Bandung area which represent polluted areas, namely Juanda Street (JD) and Kebon Kawung (KK), and Padalarang Street (PD) and one location which represent as a control area with low pollution levels, namely Curug Cimahi (CC). Lichen microstructure scanning was performed using a Scanning Electron Microscope (SEM), and the presence of elements was detected through Energy Dispersive X-ray Spectroscopy (EDS). The SEM analysis revealed that samples from areas with higher air pollution levels exhibited obvious damage to their thallus, characterized by a more porous structure and the presence of cuboidal particles. Conversely, samples from control area showed a more compact structure. The EDS observations identified 14 elements present in the lichen tissues, ranked in descending order of abundance: C>Ca>O>Pb>Cu>Mn>Zn>Fe>Cr>Al>Cl>Se>Cd>K. The composition and quantity of these elements in lichen tissues were influenced by the level of air pollution generated by the number of vehicles passing through the area. The more vehicles, the higher the level of air pollution, resulting in greater stress for the D. picta population. [ABSTRACT FROM AUTHOR]

Updated formation and structure models of Jupiter predict a metal-poor envelope. This is at odds with the two to three times solar metallicity measured by the Galileo probe. Additionally, Juno data imply that water and ammonia are enriched. Here, we explore whether Jupiter could have a deep radiative layer separating the atmosphere from the deeper interior. The radiative layer could be caused by a hydrogen-transparency window or depletion of alkali metals. We show that heavy-element accretion during Jupiter's evolution could lead to the desired atmospheric enrichment and that this configuration would be stable over billions of years. The origin of the heavy elements could be cumulative small impacts or one large impact. The preferred scenario requires a deep radiative zone, due to a local reduction of the opacity at ∼2000 K by ∼90%, which is supported by Juno data, and vertical mixing through the boundary with an efficiency similar to that of molecular diffusion (D ≲ 10−2 cm2 s−1). Therefore, most of Jupiter's molecular envelope could have solar composition while its uppermost atmosphere is enriched with heavier elements. The enrichment likely originates from the accretion of solid objects. This possibility resolves the long-standing mismatch between Jupiter's interior models and atmospheric composition measurements. Furthermore, our results imply that the measured atmospheric composition of exoplanets does not necessarily reflect their bulk compositions. We also investigate whether the enrichment could be due to the erosion of a dilute core and show that this is highly unlikely. The core-erosion scenario is inconsistent with evolution calculations, the deep radiative layer, and published interior models. [ABSTRACT FROM AUTHOR]