Mass Nuclei Research Articles

Deciphering the JWST spectrum of a ‘little red dot’ at z ∼ 4.53: An obscured AGN and its star-forming host

JWST has revealed a class of numerous, extremely compact sources with rest-frame red optical/near-infrared (NIR) and blue ultraviolet (UV) colours nicknamed ‘little red dots’. We present one of the highest signal-to-noise ratio JWST NIRSpec prism spectra of a little red dot, J0647_1045 at z = 4.5319 ± 0.0001, and examine its NIRCam morphology to differentiate the origin of the UV and optical/NIR emission and elucidate the nature of the little red dot phenomenon. J0647_1045 is unresolved (re ≲ 0.17 kpc) in the three NIRCam long-wavelength filters but significantly extended (re = 0.45 ± 0.06 kpc) in the three short-wavelength filters, indicating a red compact source in a blue star-forming galaxy. The spectral continuum shows a clear change in slope, from blue in the optical/UV to red in the rest-frame optical/NIR, which is consistent with two distinct components fit by power laws with different attenuations: AV = 0.38 ± 0.01 (UV) and AV = 5.61 ± 0.04 (optical/NIR). Fitting the Hα line requires both broad (full width at half maximum of ∼4300 ± 100 km s−1) and narrow components, but none of the other emission lines, including Hβ, show evidence of broadness. We calculated AV = 0.9 ± 0.4 from the Balmer decrement using narrow Hα and Hβ and AV > 4.1 ± 0.1 from broad Hα and an upper limit on broad Hβ, which is consistent with blue and red continuum attenuation, respectively. Based on a single-epoch Hα line width, the mass of the central black hole is 8−0.4+0.5 × 108 M⊙. Our findings are consistent with a multi-component model, in which the optical/NIR and broad lines arise from a highly obscured, spatially unresolved region, likely a relatively massive active galactic nucleus, while the less obscured UV continuum and narrow lines arise, at least partly, from a small but spatially resolved star-forming host galaxy.

Shock wave propagation in a real gas with or without gravitational field in the presence of magnetic field and monochromatic radiation via group invariance method

PurposeThis article aims to find the similarity solutions for the one-dimensional motion of spherical symmetric shock wave in non-ideal gas influenced by the azimuthal magnetic field and monochromatic radiation in the presence or absence of gravitational field. This paper also aims to study the effects of physical parameters on the strength of shock wave, and on the flow variables in the flow-field region behind the shock front.Design/methodology/approachThe Roche model is used to describe the gravitational field effects due to a massive nucleus at the point of symmetry. To derive the similarity solutions, the Lie group symmetry method has been used. Also, the numerical solutions to the present problem are obtained by using Rung–Kutta method of the fourth order with the use of Mathematica software. The effects of variation in the parameter of non-idealness of the gas, the gravitation parameter, the strength of the ambient magnetic field and the adiabatic index of the gas on the shock wave, and on the flow variables is discussed. A comparative study between with and without gravitational field is also, made.FindingsFor different choices of the arbitrary constants that appeared in the solution of infinitesimal generators, we have obtained seven distinct cases of similarity solutions. In the absence of the gravitational field, the similarity solution exists to the power and exponential law shock paths, but in the presence of gravitational field, the similarity solution exists to the power law shock path case only. In the absence of gravitational field, the shock strength is enhanced in the exponential law shock path case in comparison to the power law shock path case. It is found that the shock wave decays with an increase in the value of the adiabatic exponent, the strength of magnetic field, non-idealness of the gas or gravitational parameter.Research limitations/implicationsThe consideration of medium under the influence of gravitational field due to a heavy nucleus at the center and presence of magnetic field decrease the shock strength. This result may be helpful in designing space vehicle and jet engine.Practical implicationsThe result of the present study may be used in the analysis of data from the measurements by space craft in the solar wind and in neighborhood of the Earth’s magnetosphere.Social implicationsThe obtained results may be used for mankind.Originality/valueThe study of spherical shock wave propagation influenced by monochromatic radiation and azimuthal magnetic field in a non-ideal gas with or without gravitational field has yet to be discussed by any authors by using the Lie group symmetry method. In this article, we have discussed all possible cases of similarity solutions using the Lie group symmetry method, which is not studied by anyone as known to us.

The generation of a multiphase medium in ‘Splash’ bridge systems: towards an understanding of star formation suppression in turbulent galaxy systems

ABSTRACT Cloud–cloud collisions in splash bridges produced in gas-rich disc galaxy collisions offer a brief but interesting environment to study the effects of shocks and turbulence on star formation rates in the diffuse intergalactic medium, far from the significant feedback effects of massive star formation and active galactic nucleus. Expanding on our earlier work, we describe simulated collisions between counter-rotating disc galaxies of relatively similar mass, focusing on the thermal and kinematic effects of relative inclination and disc offset at the closest approach. This includes essential heating and cooling signatures, which go some way towards explaining the luminous power in H$_2$ and [C ii] emission in the Taffy bridge, as well as providing a partial explanation of the turbulent nature of the recently observed compact CO-emitting clouds observed in Taffy by the Atacama Large Millimeter Array (ALMA). The models show counter-rotating disc collisions result in swirling, shearing kinematics for the gas in much of the post-collision bridge. Gas with little specific angular momentum due to collisions between counter-rotating streams accumulates near the centre of mass. The disturbances and mixing in the bridge drive continuing cloud collisions, differential shock heating, and cooling throughout. A wide range of relative gas phases and line-of-sight velocity distributions are found in the bridges, depending sensitively on initial disc orientations, and the resulting variety of cloud collision histories. Most cloud collisions can occur promptly or persist for quite a long duration. Cold and hot phases can largely overlap throughout the bridge or can be separated into different parts of the bridge.

Circumgalactic Enrichment in Local Dwarf Galaxies as Probed by Star-Formation Driven Outflows

Galactic feedback driven by massive stars and active galactic nuclei plays a fundamen-tal role in regulating galaxy formation and evolution. In particular, intense starburst episodes can generate strong outflows able to suppress star formation by expelling large amount of dust and metals out of the galaxies, possibly enriching their circum (or even inter) galactic media. Local dwarf galaxies are particularly sensitive to feedback processes and offer a unique opportunity to study these phenomena in great details. We search for outflow signatures in a sample of ∼ 30 lo-cal dwarf galaxies drawn from the Dwarf Galaxy Survey. We make use of Herschel/PACS archival data to detect atomic outflows in the broad wings of observed [CII] 158 µm line profiles. We find that atomic outflows in these galaxies have typical mass-loading factors consistent with unity and velocities high enough to bring gas and dust outward. Our results can be used as input for chemical models, posing new constraints on the processes of dust growth and destruction in the interstellar medium of galaxies.

On the Importance of Inelastic Interactions in Direct Dark Matter Searches

The approach proposed earlier for describing the scattering of weakly interacting nonrelativistic massive neutral particles off nuclei is used as the basis to derive explicit expressions for the event countingrate expected in experiments aimed at directly detecting dark matter (DM) particles. These expressions make it possible to estimate the rates in question with allowance for both elastic (coherent) and inelastic (incoherent) channels of DM particle interaction with a target nucleus. Within this approach, the effect of a nonzero excitation energy of the nucleus involved is taken into account for the first time in calculating the contribution of inelastic processes. A correlation between the excitation energy and admissible values of the kinetic recoil energy of the excited nucleus constrains substantially the possibility of detection of the inelastic channel with some nuclei. In addition to the standard model of the DM distribution in theMilkyWay Galaxy, the effect of some other models that allow significantly higher velocities of DMparticles is considered. A smooth transition from from the dominance of the elastic channel of the DM particle–nucleus interaction to the dominance of its inelastic channel occurs as the nuclear recoil energy TA grows. If the DM detector used is tuned to detecting elastic-scattering events exclusively, then it cannot detect anything in the casewhere the nuclear recoil energy turns out to be belowthe the detection threshold. As TA grows, such a detector loses the ability to see anything, since elastic processes quickly become nonexistent. Radiation associated with the deexcitation of the nucleus becomes the only possible signature of the interaction that occurred. In the case of a spin-independent interaction, the inelastic contribution becomes dominant rather quickly as TA grows, while the differential event counting rate decreases insignificantly. If a DMparticle interacts with nucleons via a spin-dependent coupling exclusively, detectors traditionally setup to detect an elastic spin-dependent DMsignal will be unable to to see anything since the signal entirely goes through the inelastic channel. It looks like the sought interactions ofDM particles may have a sizable intensity, but the instrument is unable to detect them.Therefore, experiments aimed at directly detecting DM particles should be planned in such a way that it would be possible to detect simultaneously two signals—that of the recoil energy of the nucleus involved and that of gamma rays having a specific energy and carrying away its excitation. A experiment in this implementation will furnish complete information about the DM interaction that occurred.

STUDY OF O(6) SYMMETRY IN 108,110,112Ru ISOTOPES BY IBM-1 CALCULATION

Interacting Boson Model (IBM-1) is very important for the low-lying combined state in even mass nuclei. We have described the O(6) limit in the 108,110,112Ru nuclei by IBM-1 model. The B(E2) strength and energy levels in different bands were established in good agreement theoretically and experimentally. The calculated potential energy surfaces (PES) of those nuclei were suggested O(6) characters.

An escaping outflow in a galaxy with an intermediate-mass black hole

ABSTRACT While in massive galaxies active galactic nucleus (AGN) feedback plays an important role, the role of AGN feedback is still under debate in dwarf galaxies. With well spatially resolved data obtained from the Multi-Unit Spectroscopic Explorer, we identify a spatially extended ($\rm \sim 3\,\, kpc$) and fast ($V_{80} \sim 471\,\, \rm km\,\,s^{-1}$) AGN-driven outflow in a dwarf galaxy: Sloan Digital Sky Survey J022849.51-090153.8 with $M_{*} \sim 10^{9.6}\,\,{\rm {\rm M}_{\odot }}$ that host an intermediate-mass black hole of $M_{\rm BH} \sim 10^5\,\,{\rm {\rm M}_{\odot }}$ and LAGN/LEdd ∼ 0.15. Through the measurement of the rotation curve, we estimate the escape velocity of the halo and the ratio of the outflow velocity to the halo escape velocity to be 1.09 ± 0.04, indicating that the outflow is capable of escaping not only the galaxy disc but the halo. The outflow size of our AGN is found to be larger than AGN in massive galaxies at the given AGN [O iii] luminosity, while the size of the photoionized narrow-line region is comparable. These results suggest the important role of AGN feedback through outflows in dwarf galaxies when their central intermediate-mass black holes accrete at high-Eddington ratios.

33Cl Spectroscopic Factors via the 32S(3He, d)33Cl One-Proton Transfer Reaction

The structure of light-to-medium mass nuclei is crucial to understand exotic phenomena in nuclear structure, including the appearance of molecular effects in light nuclei and their impact in nuclear astrophysics. In this paper, a new experiment to probe one-proton spectroscopic factors of bound and unbound states in the sd-nucleus 33Cl is discussed. The experiment exploits the reaction 32S(3He, d)33Cl* at 9.68 MeV bombarding energy. This reaction is suitable to probe the single-particle structure of 33Cl states with respect to the population of 1d 3/2, 1f 7/2 and 2p 3/2 shells. Crucial aspects of the investigation are the use of an enriched, high-purity, 32S target and a new generation hodoscope with improved angular resolution, allowing to obtain high-precision angular distribution of the differential cross section in a broad angular range. Results are interpreted by means of finite-range DWBA and coupled-channel calculations.

Biogenetic peloidal micrites within coral skeletons cause geochemical anomalies in reef limestones, Zhongsha Atoll, South China Sea

High-magnesian calcite (HMC) peloidal micrite is a ubiquitous synsedimentary cement observed in abundance in the Holocene cryptic niches of coral intraskeletal pores and borings at Zhongsha Atoll in the South China Sea. In this study, we assessed the petrographic and geochemical effects of these intraclasts during early diagenesis. Peloidal micrites with an average diameter of 20–40 μm were composed of radially arranged rhombic micro-crystals of HMC (∼20 mol% MgCO3) and massive micritic nuclei. Some living bacterial/algal clumps in peloidal micrites are associated with bioluminescence and manifest an organic-rich micro-environments. Fragmented calcified cyanobacterial sheaths, which are components of the peloidal nuclei, further enhance biogenetic carbonate precipitation throughout peloidal micrite formation. The stable isotope characteristics of the peloidal microfabrics (average δ13C of 2.55 ± 0.15‰ and δ18O of −1.64 ± 0.25‰) suggest that photosynthesis and heterotrophic decomposition promoted peloidal micrite precipitation by increasing the carbonate saturation. Plentiful peloidal micrites within the intraskeletal pores also influenced the geochemical signatures of the bulk reef limestone. Owing to the presence of mixed HMC peloidal micrites, the δ13C and δ18O values of the bulk limestone (0.26 ± 1.04 and-3.82 ± 1.02‰, respectively) were elevated and fluctuated widely compared with pristine coral skeletons (−3.43 ± 0.48‰ and − 5.75 ± 0.278‰, respectively). Enriched Mn and depleted Sr contents led to an increase in the Mn/Sr diagenetic proxy. The co-occurrence of HMC peloidal micrites and elevated Mg/Ca, Mn/Sr, δ13C, and δ18O ratios indicate that the HMC peloidal micrites played an essential role in these geochemical variations. We, therefore, propose performing a comprehensive diagenetic evaluation before geochemical analyses of reef limestone. In such cases, selective micro-analysis of pristine areas in altered limestone would yield more robust reconstructions based on corals.

Modeling heavy-ion fusion cross section data via a novel artificial intelligence approach

We perform a comprehensive analysis of complete fusion cross section data with the aim to derive, in a completely data-driven way, a model suitable to predict the integrated cross section of the fusion between light-to-medium mass nuclei at above barrier energies. To this end, we adopted a novel artificial intelligence approach, based on a hybridization of genetic programming and artificial neural networks, capable to derive an analytical model for the description of experimental data. The approach enables to perform a global search for computationally simple models over several variables and a considerable body of nuclear data. The derived phenomenological formula can serve to reproduce the trend of fusion cross section for a large variety of light to intermediate mass collision systems in an energy domain ranging approximately from the Coulomb barrier to the onset of multi-fragmentation phenomena.

DGFRS-2—A gas-filled recoil separator for the Dubna Super Heavy Element Factory

The main goal of development of the new Dubna Gas-Filled Recoil Separator (DGFRS-2) is to sufficiently improve the efficiency of studies on heavy and superheavy nuclei at the Super Heavy Element Factory of the Flerov Laboratory of Nuclear Reactions (FLNR) at the Joint Institute for Nuclear Research. The use of beams with the intensity up to 6×1013 s−1 (10 pμA) delivered by the DC280 cyclotron requires an effective setup providing high suppression of background reaction products. The described gas-filled separator is optimized for synthesis and study of heavy isotopes produced in complete fusion reactions of massive nuclei. Basic characteristics of DGFRS-2, as well as the results of the first test experiments, are presented. In comparison to the DGFRS-1, the transmission efficiency was doubled, and the background was reduced by a factor 200.

Reaction dynamics of the C12+Ta181 system near the Coulomb barrier: Evidence of fusion-fission events

Background: Interaction of a heavy projectile with a heavy target produces a massive compound nucleus (CN), which deexcites through two possible modes: evaporation of light particles and fission. In order to develop a clear understanding of fusion-fission (FF) dynamics, it is important to explore the preactinide region at energies around and above the Coulomb barrier.Purpose: The objective is to study the dynamics involved in the fusion of $^{12}\mathrm{C}$, a cluster structured projectile, with $^{181}\mathrm{Ta}$ target, at energies within 4.3--6.0 MeV/nucleon, by measuring the production cross sections of the radionuclides formed through complete/incomplete fusion (CF/ICF) and fission processes. In addition, the mass distribution of fission fragments, which is an important fission observable, is probed for a better understanding of dynamics.Method: Tantalum foil, backed by the aluminum catcher, arranged in a stack, was bombarded by $^{12}\mathrm{C}$ ions of 52--73 MeV energy. The off-beam $\ensuremath{\gamma}$-ray spectrometry method was adopted to measure the activity of the residues produced in each Ta target after the end of bombardment (EOB), and cross sections were calculated. To analyze the experimental cross sections, PACE4 and EMPIRE3.2.2 reaction model codes were employed. Further, the mass distribution of fission fragments was explored to obtain mass variance information.Results: In general, measured excitation functions of the residues produced through the evaporation of particles in $^{12}\mathrm{C}+^{181}\mathrm{Ta}$ reaction showed good agreement with the predictions of PACE4. ICF of $^{12}\mathrm{C}$ in $^{181}\mathrm{Ta}$ target with strength up to $7.7%$ has been observed and compared with the strength deduced from previously reported data for the same system. However, no signature of precompound processes has been observed in this study. A total of 12 fission fragments within $71\ensuremath{\le}A\ensuremath{\le}135$ mass range have been identified. Further, mass variance is rising with increasing mass asymmetry, which hints at the importance of entrance-channel parameters' role in deciding the spread of the mass distribution.Conclusions: Good agreement of PACE4 with the excitation functions of $xn$ channel evaporation residues confirms their production through the CF mechanism. Enhancement of cross sections in the $\ensuremath{\alpha}xn$ channel is attributed to the ICF process. Further, evidence of the production of fission fragments through a compound nuclear mechanism is indicated as a broad and symmetric mass distribution, observed through the Gaussian fitting. The trend of mass variance with rising excitation energy and mass asymmetry is found to be growing.

Mass Symmetry

There is symmetry in the nature. Then, there should also be symmetry in physics since physics describes the phenomena of nature. In fact, it occurs in most of the phenomena explained by physics as for example: a particle has positive or negative charges, spins up or down, north or south magnetic poles. In this form, the particle should also have mass symmetry. For convenience and due to later explanations, I call this mass symmetry or mass duality as follows: mass and mass cloud. The mass symmetry can be corroborated in the experiments of the hydrogen spectrum, the Bohr model and the solution of the Schrödinger equation. The mass cloud is located in the respective orbitals given by the Schrödinger equation. The orbitals represent the possible locations or places of the particle which is determined probabilistically by the respective Schröndiger equation. For the proton, part of the mass of the uncharged proton is distributed in the orbital or mass cloud around the mass that contains the positive charge. Thus, the positive charge in the proton is concentrated in its mass nucleus with an uncharged mass cloud around its nucleus distributed in the orbitals. For the electron, part of the mass of the uncharged electron is distributed in the orbital or mass cloud around the mass that contains the negative charge. Thus, the negative charge in the electron is concentrated in its mass nucleus with an uncharged mass cloud around its nucleus distributed in the orbitals. For example, in the formation of the hydrogen atom, a part of the mass cloud of the proton interacts with the mass cloud of the electron, and the total mass energy lost in this interaction is transformed into electromagnetic energy according to Einstein's equation: E=mc2 and the variant mass formula discovered and developed by myself. Then, the two particles join together due to this interaction and the electrostatic force between the two particles. Therefore, the electron and proton are bound together in the hydrogen atom by the mass cloud of the electron and proton with some mass cloud lost in the interaction and converted to electromagnetic energy or photons. Then, it is right this mass symmetry, since the electron and the proton in the interaction of the mass cloud lose mass but do not lose electric charge. In this form, it is justified the existence of a mass cloud. In the formation of the Hydrogen atom, the electron-proton system when approaching gains a potential energy of 27.2 eV (13.6 eV*2) but then when the electron bond occurs in the shell with quantum state n =1, energy of 13.6 eV is emitted as electromagnetic energy or photons and the remaining 13.6 eV remains as kinetic energy of the electron. Then, the Hydrogen atom has 13.6 eV of additional energy/mass than the sum of the energy/mass of the proton plus the electron. Therefore, 13.6 eV is needed to ionize the Hydrogen atom and expel the electron from the atom. The mass/energy reduction of the proton and electron is 13.6/2 eV for each particle due the emission of 13.6 eV as electromagnetic energy. Therefore, the main function of the mass cloud is the binding energy. The mass cloud interaction generates binding energy between the electrons and the nucleus in the atom through the protons and between the nucleons in the nucleus: protons with protons, neutrons with neutrons, and protons with neutrons. The nuclear force between two nucleons is characterized by being strong and short-range. Also, it can be justified by the existence of the mass cloud: the mass clouds of nucleons within the nucleus interact with each other without any effect on the proton charge. This scientific research presents evidence of the existence of the mass symmetry based in the Einstein's equation and in the Variant Mass formula for the Electron in the atom discovered and demonstrated by myself where experimental results are detailed.

Mass & Quark Symmetry: Mass and Mass Cloud (The Yin Yang): Atom Binding Energy; Molecules Binding Energy; Binding energy between the nucleons in the nucleus; Particle Interaction Energy between particle and antiparticle; Quark Symmetry & Quark Confinement

The symmetry occurs in most of the phenomena explained by physics, for example, a particle has positive or negative charges, and the electric dipoles that have the charge (+q) and (-q) which are at a certain distance (d), north or south magnetic poles and for a magnetic bar or magnetic compass with two poles: North (N) and South (S) poles, spins up or down of the electron at the atom and for the nucleons in the nucleus In this form, the particle should also have mass symmetry. For convenience and due to later explanations, I call this mass symmetry or mass duality as follows: mass and mass cloud. The mass cloud is located in the respective orbitals given by the Schrödinger equation. The orbitals represent the possible locations or places of the particle which are determined probabilistically by the respective Schröndiger equation. For example and for the proton, the positive charge is concentrated in its mass nucleus with an uncharged mass cloud around its nucleus distributed in the orbitals or mass clouds. For the electron, the negative charge is concentrated in its mass nucleus with an uncharged mass cloud around its nucleus distributed in the orbitals or mass clouds. Besides, in the formation of the hydrogen atom, a part of the mass cloud of the proton interacts with the mass cloud of the electron, and the total mass-energy lost in this interaction is transformed into electromagnetic energy according to Einstein's equation: E=mc2 and the variant mass formula discovered and developed by myself: Giovanni Alcocer Variant Formulas. Therefore, the electron and proton are bound together in the hydrogen atom due to the electrostatic force between the two particles and the mass cloud of the electron and proton with some mass cloud lost in the interaction and converted to electromagnetic energy or photons. Then, it is right to assume this mass symmetry, since the electron and the proton in the interaction of the mass cloud lose mass but do not lose electric charge. In this form, it is justified the existence of a mass cloud. Therefore, the main function of the mass cloud is the binding energy. The mass cloud interaction generates binding energy between the electrons and the nucleus in the atom through the protons and between the nucleons in the nucleus: protons with protons, neutrons with neutrons, and protons with neutrons. The nuclear force between two nucleons is characterized by being strong and short-range. Also, it can be justified by the existence of the mass cloud: the mass clouds of nucleons within the nucleus interact with each other without any effect on the proton charge. In the same form and due to the quarks having mass and charge (and inclusive colors), the quarks have also the same mass symmetry: mass and mass cloud. Thus, the electrical charge is stored in the mass of the quarks and the mass cloud allows the confinement or the respective binding between quarks. Then, the following questions are explained and answered simply in this research article: why a particle does not exist with only one quark? why the quarks are confined to the nucleus? and which is the origin of the nuclear forces? On other hand, there are particles with two quarks (mesons), particles with three quarks (baryons) and then, it is very probable to find particles with more than three quarks (quaternions). This scientific research presents evidence of the existence of mass symmetry: mass and mass cloud and the interaction between the mass cloud of the particles (The Yin Yang Interaction) based on Einstein's equation and in the Variant Mass formula for the Electron in the atom discovered and demonstrated by myself where experimental results are detailed.

Statistical fluctuations of negative parity levels in even mass nuclei

This study presents the first statistical analysis on the correlation of negative parity states. All the available experimental data of 1−&2− levels of the even mass nuclei in the 16≤A≤212 mass region are used to prepare the sequences and classified as their masses. Random matrix theory together with a usual least - square procedure are used to extract the chaos measures of Berry – Robnik distribution function for different sequences in the framework of nearest neighbor spacing distribution. Also, we considered the chaotic degrees of these levels in relation to different modes of calculated deformations values and the shell model configuration of the last protons and neutrons of even mass nuclei. The results of this consideration suggest the most correlation of 1− levels in the A<50, mass area, but similar statistics of 2− levels are yield in the 150<A<200 region. The most GOE-like behavior of 1− levels is reported for sequences that the last protons lie in the d3/2 orbitals, and the neutrons filled the h9/2 orbitals, but for 2− levels, nuclei with 1h11/2 and 1i13/2 configurations for respectively, protons and neutrons, show the maximum correlation. Also, the results of this study suggest the most correlation of 1− levels for some mass regions which have the maximum values of the averaged quadrupole and hexacontatetrapole deformations.

Infrared Emission from Cold Gas Dusty Disks in Massive Ellipticals

Abstract What is the expected infrared output of elliptical galaxies? We report the latest findings obtained in this high time resolution (∼10 yr) and high spatial resolution (2.5 pc at center) study. We add a set of grain physics to the Massive active galactic nucleus (AGN) Controlled Ellipticals Resolved code, including (a) dust grains made in passive stellar evolution; (b) dust grain growth due to collision and sticking; (c) grain destruction due to thermal sputtering; (d) dust cooling of hot gas via inelastic collisions; and (e) radiation pressure on dust grains. The code improvements enable us to analyze metal depletion and AGN obscuration due to dust, and to assess its infrared output. We simulate a representative massive elliptical galaxy of a central stellar velocity dispersion ∼260 km s−1 and modest rotation. We find that: (1) the circumnuclear disk (∼1 kpc in diameter) is dusty in its outer region where most of the metals are contained in dust grains, while in the inner disk, dust grains are mostly destroyed by the AGN irradiation; (2) the dusty disk is optically thick to both the starlight within the disk and the radiation from the central AGN; thus the AGN is obscured behind the disk, and the covering factor is ∼0.2; and (3) the duty cycles of the AGN activities, star formation, and the dust infrared luminosity roughly match observations; e.g., in most of its lifetime, the simulated galaxy is a stereotypical “quiescent” elliptical galaxy with , but it can reach ≳1046 erg s−1 during outbursts with a star formation rate .

Multinucleon transfer in the interaction of 977 MeV and 1143 MeV Hg204 with Pb208

A previous study of symmetric collisions of massive nuclei has shown that current models of multi-nucleon transfer (MNT) reactions do not adequately describe the transfer product yields. To gain further insight into this problem, we have measured the yields of MNT products in the interaction of 977 (E/A = 4.79 MeV) and 1143 MeV (E/A = 5.60 MeV) $^{204}$Hg with $^{208}$Pb. We find that the yield of multi-nucleon transfer products are similar in these two reactions and are substantially lower than those observed in the reaction of 1257 MeV (E/A = 6.16 MeV) $^{204}$Hg + $^{198}$Pt. We compare our measurements with the predictions of the GRAZING-F, di-nuclear systems (DNS) and improved quantum molecular dynamics (ImQMD) models. For the observed isotopes of the elements Au, Hg, Tl, Pb and Bi, the measured values of the MNT cross sections are orders of magnitude larger than the predicted values. Furthermore, the various models predict the formation of nuclides near the N=126 shell, which are not observed.

Ancistrosecolines A-F, Unprecedented seco-Naphthylisoquinoline Alkaloids from the Roots of Ancistrocladus abbreviatus, with Apoptosis-Inducing Potential against HeLa Cancer Cells.

Ancistrosecolines A-F (8-13) are the first seco-type naphthylisoquinoline alkaloids discovered in Nature. In all these novel compounds, the tetrahydroisoquinoline ring is cleaved, with loss of C-1. They were isolated from the root bark of Ancistrocladus abbreviatus (Ancistrocladaceae), along with 1-nor-8-O-demethylancistrobrevine H (14), which is the first naturally occurring naphthylisoquinoline lacking the otherwise generally present methyl group at C-1. The stereostructures of the new alkaloids were established by HRESIMS, 1D and 2D NMR, oxidative degradation, and experimental and quantum-chemical ECD investigations. Ancistrosecolines A-F (8-13) and 1-nor-8-O-demethylancistrobrevine H (14) are typical Ancistrocladaceae-type metabolites, i.e., oxygenated at C-6 and S-configured at C-3, belonging to the subclasses of 7,1'- and 7,8'-coupled alkaloids. The biaryl linkages of 8-14 are rotationally hindered due to bulky ortho-substituents next to the axes. Owing to the constitutionally unsymmetric substitution patterns on each side of the axis, this C-C single bond represents an element of chirality in 1-nor-8-O-demethylancistrobrevine H (14) and in ancistrosecolines A-D (8-11). In ancistrosecolines E (12) and F (13), however, the likewise rotationally hindered biaryl axes do not constitute chiral elements, due to a symmetric substitution pattern, with its identical two methoxy functions at C-6 and C-8 in the phenyl subunit. And these two methoxy groups are, for the first time, not constitutionally heterotopic, but diastereotopic to each other. Ancistrosecoline D (11) exhibits strong cytotoxicity against HeLa cervical cancer cells. As visualized by Hoechst nuclei staining and by real-time imaging experiments, 11 induced massive nuclei fragmentation in HeLa cells, leading to apoptotic cell death.

Search for WIMP-129Xe inelastic scattering using particle identification in the XMASS experiment

The inelastic scattering of Weakly Interacting Massive Particles (WIMPs) and 129Xe nuclei was searched for in the XMASS experiment. When excited by the inelastic scattering, the nuclei emit 39.6 keV γ-ray. The exposure of the data was 327 kg × 800.0 days. To improve the sensitivity of the signal, the events were classified by their pulse shapes, which discriminates between γ-rays and β-rays. As no significant signal was found, the upper limits of the inelastic channel cross section at the 90% confidence level were set. For a 200 GeV/c 2 WIMP, the limit was 4.1 × 10−39 cm2. This is the most stringent limit of the SD WIMP-neutron interaction.

TEAOH‐Templated SAPO‐34 Zeolite with Different Crystallization Processes and Silicon Sources: Crystallization Mechanism and MTO Performance

SAPO‐34 zeolites were synthesized by one‐, two‐, and three‐stage crystallization processes with fumed silica (FS), acidic silica sol (AS), basic silica sol (BS) and tetraethoxysilane (TEOS) as silicon sources. Properties of samples were characterized by XRD, SEM, EDX, N2‐adsorption/desorption, NH3‐TPD and 29Si NMR. In contrast with one‐ and two‐stage processes, the three‐stage one favors the formation of SAPO‐34s with higher purity, higher Si/Al ratio, smaller crystallite/crystal size, better dispersion and more acidic sites. Crystallization mechanism was proposed. It is supposed that three‐stage process favors the formation of high supersaturated SBUs (secondary building units) and CBUs (composite building units) before nucleation. Thus massive nuclei are formed during nucleation and well‐dispersed small size SAPO‐34 crystals are formed in three‐stage process. Three‐stage SAPO‐34s are longer catalytic lifetime and better olefin selectivity in MTO process. TEOS‐3 has the best MTO performance. It was found that acidity of sample and mesopores in 2–4 nm range have little effect on the MTO performance of SAPO‐34. Catalytic lifetime and olefin selectivity are mainly depending on the size of crystallites, the dispersity of crystallites, and the purity of SAPO‐34.