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type ia supernovae almost certainly involve the thermonuclear explosion and unbinding of a carbon-oxygen white dwarf, but understanding both the possible role of a binary companion and the mechanism of explosion remain open problems in supernova research. thanks to theoretical developments in the last decade, we now ha... | late-phase radiative transfer of type ia supernovae |
we provide a set of stellar evolution and nucleosynthesis calculations that applies established physics assumptions simultaneously to low- and intermediate-mass and massive star models. our goal is to provide an internally consistent and comprehensive nuclear production and yield database for applications in areas such... | vizier online data catalog: nugrid stellar data set i. yields from h to bi (pignatari+, 2016) |
influence of magnetorotational instabilities in astrophysical plasma at supernova explosion on synthesis of chemical elements is investigated. at field strength less than 10 teratesla nuclear magnetic susceptibility exhibits linear regime with enhanced nuclear binding energy for open shell nuclei. effects of ultra-stro... | synthesis of magnetized nuclei at supernova explosion |
the study of type ia supernovae (sne ia) has undergone a revolution within the last year following the discovery of three extremely unique stars in gaia's data release 2. their hypervelocities (1000-2500 km/s), atmospheric compositions (predominantly c/o with contributions from mg, si, s, and fe-group elements), inflat... | uv properties of the first known surviving companions of type ia supernovae |
we propose to use wfc3 photometry from the near uv to the near ir to sample the bolometric light curve of the nearby type ia supernova (sn ia) sn2012cg at late times (>900 days after maximum light). this light curve will allow us to conduct a fundamental test of the theoretically predicted behavior of sn ia light cu... | constraining type ia supernova nucleosynthesis and explosion models using late-time photometry of sn2012cg |
the vp-process is a new nucleosynthetic scenario, proposed 2006, which supposed to take place at the very early epoch of type ii supernova, involving nuclear reactions of proton-rich nuclei not only with protons and alphas, but also with neutrons due to the neutrino processes. the vp-process is one of the key processes... | experimental challenge to the vp-process in type ii supernovae |
very metal poor stars, [fe/h] < -2.0, are old and have been contaminated by only a few enrichment events like supernovae and neutron star mergers. to better understand the nucleosynthesis of heavy elements at these sites, specifically that of rapid neutron-capture (r-process) elements, a large catalogue of r-process... | searching for r-process enhanced metal poor stars in the rave survey |
w49b is a galactic supernova remnant whose origin is still debated. is it the remains of an unusual asymmetric type 1a supernova or of a jet-driven core collapse supernova? using the x-ray analysis method, smoothed particle inference (spi), we dig deeper into understanding the complex properties of snr w49b. we do this... | investigating the origin of the supernova remnant w49b |
we perform sph simulations coupled with nuclear reactions to follow tidal disruption events (tdes) of white dwarfs (wds) by intermediate mass black holes (imbhs). we consider an oxygen-neon-magnesium (onemg) wd with 1.2m ⊙ as well as a helium (he) wd with 0.3m ⊙, and a carbon-oxygen (co) wd with 0.6m ⊙. our wd models h... | explosive nucleosynthesis in tidal disruption events of massive white dwarfs, and their debris |
we study r-process enrichment of dwarf galaxies in the early universe due to the common envelope jets supernova (cejsn) r-process scenario, where a neutron star (ns) launches jets as it collides with the core of a giant star. we compare its characteristics to the neutron ns-ns merger r-process scenario and the collapsa... | r-process enrichment in the early universe by the common envelope jets supernova r-process scenario |
diffuse gamma-ray emission from the decay of radioactive 26al is a messenger from the nucleosynthesis activity in our current-day galaxy. because this material is attributed to ejections from massive stars and their supernovae, the gamma-ray signal includes information about nucleosynthesis in massive star interiors as... | gamma-ray spectroscopy of galactic nucleosynthesis |
gamma-ray lines from radioactive decay of unstable isotopes which are co-produced by nucleosynthesis are being measured with esa's integral space mission and its gamma-ray spectrometer spi. 56 ni is produced in large amounts in supernova explosions, and its decay through 56 co (within ~ 8 days) and then to 56 fe (withi... | gamma-rays from sn2014j and their implications for type ia supernovae |
the allowed gamow-teller (gt) strength distributions and associated weak interaction rates on fp-shell nuclei play crucial role in several astrophysical processes, particularly in nucleosynthesis, stellar evolution and supernova explosions. results from simulation show that the electron capture (ec) rates on medium-hea... | allowed gamow-teller strength distributions and stellar electron capture rates on odd-a nuclei |
the lighter heavy elements of the first r-process peak, between strontium and silver, can be synthesized in the moderately neutron-rich neutrino-driven ejecta of either core-collapse supernovae or neutron star mergers via the weak r-process. this nucleosynthesis scenario exhibits uncertainties from the absence of exper... | constraining nucleosythesis in neutrino-driven winds using the impact of (α, xn) reaction rates |
nucleosynthesis in the νp-process occurs in regions of slightly proton-rich nuclei in the neutrino-driven wind of core-collapse supernovae. the process proceeds via a sequence of (p,γ) and (n,p) reactions, and depending on the conditions, may produce elements between ni and sn. recent studies show that a few key (n,p) ... | first (p,n) reaction measurement in inverse kinematics with secar |
state-of-the-art cosmological hydrodynamic simulations combine a vast range of astrophysics together in a single tool capable of confronting a wide range of observations. these tools track the stellar nucleosynthetic yields from core-collapse & type ia supernovae, agb stars, and supergiant winds on the cosmological... | the global oxygen yield budget followed in hydrodynamic simulations |
type ia supernovae (sn ia) have enormous importance to cosmology and astrophysics, but we still lack a detailed understanding of their progenitor systems and explosion mechanisms. at late times, in the nebular phase, the ejecta become optically thin, allowing us to "see through" the supernova and directly probe its com... | see through supernovae: nebular spectroscopy of exploding white dwarfs |
"light" heavy elements (z = 38 − 47) can be synthesized in the neutrino-driven ejecta of core-collapse supernovae via the weak r-process. this nucleosynthesis scenario exhibits uncertainties from the absence of experimental data from (α, n) reactions on neutron-rich nuclei, and are mostly based on statistical model cal... | exploring the uncertainties of (α, xn) reactions for the weak r-process |
galactic chemical evolution is driven by the complicated interplay of gas accretion, galaxy mergers, star formation, stellar feedback, mixing and turbulence in the ism, and galactic outflows. stellar feedback is fundamental in this evolution. how metals -- ejected in stellar winds and supernovae -- mix with a multi-pha... | feedback and chemical enrichment in low mass dwarf galaxies: insights from simulations tracking individual stars |
type ia supernovae (sne ia) are thought to originate from the thermonuclear explosion of white dwarfs. type ia sne serve as standardizable candles for measuring cosmological distances and enrich the interstellar medium with iron group and intermediate mass elements. recent x-ray observations of the near-chandrasekhar m... | simulations of neutron-rich ejecta of supernova remnant 3c 397. |
the lighter heavy elements of the first r-process peak, between strontium and silver, can be synthesized in the moderately neutron-rich neutrino-driven ejecta of either core-collapse supernovae or neutron star mergers via the weak r-process. this nucleosynthesis scenario exhibits uncertainties from the absence of exper... | using (α, xn) reaction rates and abundance ratios to constrain the weak r-process |
our understanding of the origin of the elements is grounded in observational abundance measurements and theoretical models of stellar explosions. the current era of big data from surveys such as apogee and galah allows us to study an unprecedented number of stars in abundance space. i use spectroscopic data and theoret... | stellar abundances in the milky way and their implications for nucleosynthesis |
supertiger (super trans-iron galactic element recorder) has had two antarctic long-duration-balloon flights. the first was a record setting 55 days during the 2012-2013 austral summer at an average float altitude of 125,000 feet, and the second was 32 days during 2019-2020 at an average float altitude of 120,000 feet. ... | supertiger instrument and galactic cosmic ray abundances from 10ne to 56ba |
neutrino-nucleus cross sections are of relevance to supernova astrophysics. these cross-sections can be grouped into three categories, those that affect supernova dynamics, supernova nucleosynthesis, and terrestrial supernova neutrino detection, each of which would benefit from experimental study. in this report only t... | sn-detection in lar-tpc and the quest for (ν-ar) cross sections |
in the coming years the facility for antiproton and ion research fair will be constructed at the gsi helmholtzzentrum für schwerionenforschung in darmstadt, germany. this new accelerator complex will allow for unprecedented and path-breaking research in hadronic, nuclear and atomic physics as well as applied sciences. ... | the facility for antiproton and ion research |
in this work, we newly perform a sequence of numerical simulations of the evolution, explosion, and nucleosynthesis for first stars with initial masses of ~140-300mȯ. furthermore, we conduct the first systematic comparison between pair-instability supernova (pisn) theoretical yields and observations using the big stell... | vizier online data catalog: stellar yields of rotating first stars. ii. (takahashi+, 2018) |
even though sne ia are crucial to cosmological studies as distance indicators, the exact nature of these systems remains theoretically ambiguous and observationally elusive. however, there is a new hope. the very late-time lightcurves of sne ia harbor important clues to the natures of their progenitor systems. first, t... | whimper of a bang: documenting the final days of the nearby type ia supernova 2011fe |
136sb is a neutron rich nucleus with one valence proton and three valence neutrons outside the doubly-magic nucleus 132sn. it plays an important role in the rapid neutron capture process (r-process) as participates in its path further connected to the nucleosynthesis and the type ii supernovae. in this work, a new β de... | new study of the neutron rich 136te isotope through decay spectroscopy |
electron-capture and β -decay rates in stellar environments are evaluated by shell-model calculations with new shell-model hamiltonians which can describe gamow-teller (gt) transitions in nuclei quite well. the weak rates in sd-shell nuclei are used to study nuclear urca processes in onemg cores of 8-10m ⊙stars. the gt... | roles of spin-dependent transitions in nuclei on astrophysical processes in stars |
type ia supernovae (sn ia) have enormous importance to cosmology and astrophysics, but we still lack a detailed understanding of their progenitor systems and explosion mechanisms. at late times, in the nebular phase, the ejecta become optically thin, allowing us to "see through" the supernova and directly probe its com... | see through supernovae: nebular spectroscopy of exploding white dwarfs |
files table1.dat to table11.dat list the nucleosynthesis yields of all models. all masses are given in solar masses. the isotope name is given in the first column. this is followed by the nucleosynthetic yields originating from the shell and core detonation for each model. file table1.dat gives the stable nuclides, rad... | vizier online data catalog: z-dependent yields of double detonations (gronow+, 2021) |
the combination of the rhinoceros windowless gas target with the 5u high-current accelerator at the notre dame nuclear science lab provides an ideal tool for measuring cross sections of astrophysical interest involving gaseous targets. the beam/target interaction point is viewed by arrays of highly-collimated silicon d... | recent measurements with the rhinoceros gas target at notre dame |
a rare sub-class of massive star explosions, known as broad-lined ic supernovae (ic-bl sne), have been highlighted as one of the potential sites of r-process nucleosynthesis capable of enriching the universe with heavy elements. these supernovae, stripped of their hydrogen and helium layers, are associated with long-du... | collapsars as sites of r-process nucleosynthesis |
radiative neutron capture is one of the key reactions in the r-process nucleosynthesis, which takes place in the neutron star mergers and in the supernova explosions. quantitative prediction of the cross section is required as the direct experimental measurement is difficult for very neutron-rich nuclei along the r-pro... | density functional approach to radiative neutron capture reactions on r-process nuclei |
supernova remnants are the site of a number of physical processes (shock-heating, non-equilibrium ionization, hydrodynamic instabilities, particle acceleration, magnetic field amplification). their related emission processes provide us with a large set of observational data. supernova remnants result from the interacti... | supernova remnants dynamics |
supernova remnants (snrs) offer the means to learn more about supernova explosions. in this talk, i will discuss a few ways in which studies of the reverse-shock heated, x-ray emitting ejecta in supernova remnants can lead to insights about these explosions and their progenitor systems. the spatial distribution of shoc... | constraining snr explosion properties from x-ray-emitting shocked ejecta |
smoothed particle hydrodynamics (sph) is a meshfree lagrangian simulation approach that has a lot of appeal for simulating catastrophic astrophysical scenarios such as mergers of compact objects, tidal disruptions, supernova explosions, etc. it provides excellent conservation properties, natural adaptive refinement in ... | simulating neutron star mergers with fully dynamical general relativistic sph |
type ia supernovae (sne ia) are some of the most luminous and consequential events in astronomy. the precise progenitor systems and explosion mechanisms that drive sne ia are still unknown however. a more accurate depiction of the origin of sne ia would serve to improve their contributions to many areas of research, in... | parameter study of double detonation type ia supernovae originating from thin-helium shell white dwarfs |
many aspects of the origin and evolution of heavy elements in nature are yet to be clearly understood. this talk will overview the current status of models for the formation of r-process, s-process and p-process elements. we summarize recent state-of the art developments of supernova and binary neutron star evolution f... | galactic chemical evolution and heavy element nucleosynthesis |
recent experimental challenges to study the explosive hydrogen burning at extremely high temperatures are discussed. along the nucleosynthetic pathway, discussions were made especially for the medium mass region, where we have possible waiting points and bottle necks which influence not only the light curve but also th... | experimental approach to explosive hydrogen burning in x-ray bursts and core-collapse supernovae |
core-collapse supernovae and neutron star mergers produce multimessenger transient signals that clue us in to the origin of the elements in the universe, the behavior of dense matter, and the nature of fundamental particles. neutrinos of different flavors in these systems carry energy and lepton number, modifying the l... | neutrino quantum kinetics with moments in neutron star mergers |
the study of the rapid neutron capture or `r process' of nucleosynthesis offers the opportunity to glean insight into where the heavy elements (those above iron) on the periodic table are created in nature. astrophysical sites, namely, supernovae and compact object mergers, e.g. two neutron stars, have long been touted... | gamma-ray signatures from the radioactive decay of r-process nuclei |
in a previously presented proof-of-principle study, we established a parameterized spherically symmetric explosion method (push) that can reproduce many features of core-collapse supernovae (ccsne) for a wide range of pre-explosion models. the method is based on the neutrino-driven mechanism and follows collapse, bounc... | vizier online data catalog: push ccsn to explosions in spherical symmetry. iii. (curtis+, 2019) |
if an astrophysical environment is hot enough, screening in the associated nuclear reactions can be modified by the presence of a relativistic electron-positron plasma. additionally, strong magnetic fields can create an additional enhancement as the electron and positron energy distribution is modified by the altered l... | nuclear reaction rates in highly magnetized relativistic plasmas: effects on pulsational pair-instability supernovae, magnetar nucleosynthesis, and other sites |
the hard x-ray spectra of snr 3c 397 derived from suzaku and xmm-newton are distinguished by high abundances of iron group elements including ni, cr and mn. consequently, 3c 397 is a strong candidate for a near-mch type ia. in this talk, i will present synthetic spectra derived from multidimensional models of snr 3c 39... | classification of synthetic spectra of hydrodynamical models of 3c 397 |
a grid of 15-80 solar mass z=0 stellar models are evolved to pre-core collapse using the stellar evolution code brahama. each initial zero-age main sequence mass model star is evolved with two different convection criteria, ledoux and schwarzchild. the choice of convection produces significant changes in the evolutiona... | impact of stellar convection criteria on the nucleosynthetic yields of population iii supernovae. |
the chemical composition of the ejecta from the violent explosions of massive stars has been vital for probing the nature of the explosions and their effect on galactic chemical evolution and universal chemical composition. the sensitivity of numerical explosive nucleosynthetic yields in core-collapse supernovae to sev... | uncertainty in explosive yields of core-collapse supernovae |
dwarf galaxies offer a unique opportunity to study the competing forces of galaxy evolution. their simpler history (i.e., small size, fewer major mergers, and lack of active galactic nuclei) enables us to isolate different physical mechanisms more easily. the effects of these mechanisms are imprinted on the galaxy's st... | chemically-deduced star formation histories of dwarf galaxies using barium |
abundances of heavy elements in dwarf galaxies reflect their early evolutionary histories. recent astronomical observations have shown that there are star-to-star scatters in the abundances of r-process elements and the decreasing trend of zn toward higher metallicity in extremely metal-poor stars. however, the enrichm... | enrichment of heavy elements in chemo-dynamical simulations of dwarf galaxies |
the 20ne(α,p)23na reaction rate is of astrophysical interest in determining the final abundances of various nuclei produced in type ia supernovae. previously, experiments in inverse kinematics have been conducted to determine this reaction rate at higher, less astrophysically relevant energies. the rhinoceros gas targe... | 20 ne(α,p)23na studied to constrain supernova type ia nucleosynthesis |
carbon fusion has been a focus of considerable study in recent years with a number of innovative direct measurements and indirect studies of this astrophysically vital reaction. carbon fusion has a strong impact on superbursts in x-ray binary systems, type ia supernovae and nucleosynthesis in massive stars. a number of... | reexamining carbon fusion |
the 20ne(α,p)23na reaction rate is particularly important in predicting final nuclei abundances for type ia supernovae, especially around temperatures of 5 gk. the corresponding gamow window for this temperature ranges from 2.4 to 5.4 mev. previous studies of this reaction have measured either the ground state, at high... | the 20ne(α,p)23na cross section studied to constrain supernova type ia nucleosynthesis |
highlights from research done on the national ignition facility (nif) laser through the discovery science program will be presented. plasma nuclear reactions relevant to stellar nucleosynthesis and nuclear reactions in high energy astrophysical scenarios are being studied. [1] equations of state (eos) at very high pres... | new regimes of hed frontier science on the national ignition facility |
the collapse of supermassive stars represents a promising avenue towards the assembly of supermassive black holes in the early universe. observing the photospheres of these stars directly, however, may be difficult because of the large distances involved. one alternative approach is to look for observables related to v... | testing the direct collapse scenario with general relativistic instability supernovae |
x-ray observations of supernova remnants allow us to investigate the elemental composition and kinematics of the supernova ejecta, offering strong constraints on the mechanisms of the stellar nucleosynthesis and explosions. moreover, the physical conditions (e.g., temperature and ionization state) offer clues to the st... | connecting supernova remnants to their progenitor systems and explosion mechanism through x-ray observations |
the nucleosynthesis reaction 12c(α,γ)16o is of utmost importance in nuclear astrophysics. the s-factor of this reaction is a major parameter for determining the abundance ratio of oxygen to carbon in stellar nucleosynthesis, which in turn plays a crucial role in understanding pre-supernova evolution. since the cross se... | feasibility studies for measuring the astrophysical s-factor of the reaction 12c(α,γ)16o via electro-disintegration at magix |
the alpha capture reaction 12c(alpha, gamma) 16o plays an important role in helium burning in massive stars and their evolution. the reaction rate at gamow energy (e 300 kev) corresponding to helium burning temperature t 0.2 gk determines - together with the triple alpha reaction - the relative amounts of carbon and ox... | study of the 12c(α,γ)16o reaction via the α-transfer reactions: 12c(6li,d)16o and 12c(7li,t)16o |
supernovae are the most colossal and awe-inspiring events that mark the end of some stars' lives, playing a crucial role in the evolution of galaxies and the synthesis of elements essential for life as we know it. during the collapse of massive stars, the extreme conditions can induce fusion reactions, creating new ato... | implementation of an autoencoder neural network to nuclear reaction kinetics |
interstellar radionuclides, such as 60fe, are produced in massive stars, ejected by supernovae and can be recovered in geological archives on earth. ferromanganese encrustations on the bottom of earth's major oceans represent one important geological archive with a time-record of interstellar radionuclides. the paper o... | re-evaluation of cosmogenic 10be dating of the ferromanganese crust va13/2 archiving interstellar radionuclides on earth |
we propose to use wfc3 photometry to construct the optical light curves of the nearby type ia supernovae sn 2015f and asassn-14lp at late times (>500 days after maximum light). these light curves will allow us to conduct a fundamental test of the theoretically predicted behavior of type ia supernova light curves at ... | going gently into the night: constraining type ia supernova nucleosynthesis using late-time photometry |
based on modern stellar simulations and observations, at least four different neutron-capture processes are needed to explain the production of heavy elements beyond iron in stars. the slow neutron-capture process (s-process) and the rapid neutron-capture process (r-process) were introduced decades ago in order to expl... | the diversity of stellar nucleosynthesis sites in the s- to i-process and n-process range |
in this work, we studied the production of heavy-mass elements, through the rapid neutron-capture mechanism (r-process), associated with different astrophysical scenarios. since the r-process consists on captures of neutrons followed by β-decays, if sterile neutrinos exist, a reformulation of the weak-decay rates due t... | impact of neutrino oscillations on the r-process in different astrophysical scenarios |
neutrino reactions on nuclei play important roles for the dynamics of supernovae and their associated nucleosynthesis. this manuscript summarizes the current status in deriving the relevant cross sections for supernova neutrinos and briefly discusses a few recent advances where | the role of neutrino-nucleus reactions in supernova dynamics and nucleosynthesis |
we propose a deep epic observation of the highly asymmetric young (lessthan 600 years old) core-collapse (cc) supernova remnant g350.1--0.3,whose spectrum is dominated by iron-rich ejecta expanding at up to 6,000km/s away from an almost-stationary thermally emitting neutron star(cco), and for which a very high nickel a... | fast iron ejecta in a very young core-collapse supernova remnant: g350.1-0.3 |
neutron-capture cross sections on unstable nuclei are key in the creation of heavy elements in our universe. these elements are created through rapid neutron capture nucleosynthesis, called the r - process, believed to occur in neutron star mergers or core-collapse supernovae. the (d,p) reaction has recently been valid... | analysis of na(ti) scintillator using spectroscopy |
the neutrino opacities of hot and dense matter play an important role in the core collapse supernovae (ccsne) explosion mechanism, the nucleosynthesis process in ccsne and binary neutron star (bns) mergers, and the fast neutrino flavor conversions. the neutrino-nucleon interactions are one of the main sources of neutri... | large scale tabulated neutrino opacity table for next-generation simulations of core-collapse supernovae/binary neutron star mergers |
the 22ne(α,n)25mg reaction is one of the most important neutron sources for s-process nucleosynthesis, which is responsible for the production of ~50% of the elements heavier than fe in the solar system. a recent experimental study (s. ota et al. 2020) indicated that the cross section at stellar temperatures might be s... | sensitivity of galactic chemical evolution to reduced 22ne(α,n)25mg cross section |
neutron star mergers (nsms) are the first verified site of rapid neutron capture (r-process) nucleosynthesis, and could emit gamma rays from the radioactive isotopes synthesized in the neutron-rich ejecta. these mev gamma rays may provide a unique and direct probe of the nsm environment as well insight into the nature ... | mev gamma rays from neutron star mergers: a distinct signature of r process fission |
the inner galactic halo is home to some of the oldest and low metallicity stars known. these stars are local enough to observe heavy element synthesis in the oldest stars in our galaxy. the purpose of this research is to analyze the distributions of neutron capture elements in low metallicity stars to help us understan... | neutron-capture elements in low metallicity stars within the inner galactic halo |
we examine how well different supernova nucleosynthesis models are able to fit observed abundances. we test different combinations of published models for core-collapse supernovae, type-ia supernovae, and stellar winds to see how well they can fit solar abundance patterns and observed abundances in the perseus cluster.... | modeling metal production in supernova |
the fast-expanding neutron-rich neutrino-driven winds in the core-collapse supernovae are favorable scenarios for the nucleosynthesis of the light-heavy elements. charge particle reactions, especially (a,xn), create seeds for the weak r-process populating abundances of near stable isotopes for the sr-ag range, for whic... | experimental investigations of the (a,xn) reactions relevant for the r-process nucleosynthesis. |
highlights from the nif laser discovery science program will be presented. examples include experiments on nuclear reactions relevant to stellar nucleosynthesis; equations of state (eos) at ultrahigh pressures (1-800 mbar) relevant to planetary interiors and cores and white dwarf envelopes; radiative shock stabilized r... | exploring the universe through discovery science on the national ignition facility (nif)* |
beta-decay rates for exotic nuclei with n = 126 relevant to r-process nucleosynthesis are studied up to z = 78 by shell-model calculations. the half-lives for the waiting-point nuclei obtained, which are short compared to a standard frdm, are used to study r-process nucleosynthesis in neutrino-driven winds and magneto-... | beta-decay rates for exotic nuclei and r-process nucleosynthesis up to th and u |
the p-nuclei are supposed to be produced in different astrophysical processes, such as rapid-proton capture, photonuclear reaction, and neutrino-induced reaction. to date, their abundance cannot be reasonably explained. in the present work, the cross sections of the 74ge (νe , e -) 74as reaction are calculated with the... | influence of neutrino-nuclear reactions on the abundance of 74se |
type ia supernovae (sne ia) are among the most energetic explosions in the universe. the discovery of the phillips relation enabled the use of sne ia as standardizable cosmological candles, and has ushered in a new era of astronomy leading to the discovery of the acceleration of the universe. however, the nature of sne... | evaluating the double-degenerate spiral type ia supernova model |
the details of the explosion mechanism of core-collapse supernovae (ccsne) are not yet fully understood. there are an increasing number of numerical examples by ab-initio core-collapse simulations leading to an explosion. most, if not all, of them represent a `slow' explosion in which the `observed' explosion energy (~... | nucleosynthesis constraints on the energy growth timescale of a core-collapse supernova explosion |
researchers are still working out where heavy metals are made in the universe. a recent publication explores ways to tell if elements heavier than iron can be created when extremely massive stars collapse to form black holes.making heavy metalsin the cores of stars, nuclear fusion combines light elements into heavier o... | finding ways to catch collapsars making heavy metals |
the long duration gamma-ray burst grb 221009a is the brightest grb in 50-years of observations and ~10,000 grbs. not only is it the brightest ever seen, but optical observations show it to be relatively local (z = 0.15), making it a very rare nearby, but high luminosity system, with an energy e_iso > 10^54 erg (if r... | heavy element formation in the brightest gamma-ray burst of all time |
in this paper we present an extension of our nucleosynthesis parameter study within the classical neutrino-driven wind scenario of core-collapse supernovae (ccsne). the principal aim of this decade-old study was to shine light on the production of the historical 'p-only' isotopes of the light trans-fe elements in the s... | on the nucleosynthetic origin of presolar silicon carbide x-grains |
the binary_c software framework models the evolution of single, binary and multiple stars, including stellar evolution and nucleosynthesis. stellar evolution includes wind mass loss, rotation, thermal pulses, magnetic braking, pre-main sequence evolution, supernovae and kicks, and neutron stars; binary-star evolution i... | binary_c: stellar population synthesis software framework |
the origin of the light, odd-z element fluorine remains uncertain, though it is thought to be produced in multiple stellar sites such as asymptotic giant branch stars, rapidly rotating massive stars, wolf-rayet stars, the v-process in core-collapse supernovae, and novae. several nucleosynthetic channels may contribute ... | fluorine abundances in local stellar populations |
supernovae (sne) produce, fragment and destroy dust, molecules and nucleosynthetic elements, and reshape and modify the ism. i will review recent infrared observations of supernova remnants (snrs) and sne which show that sne are important sites of dust and molecule formation and are major dust creators in the universe.... | dust and molecule formation and processing in supernovae and their remnants |
the distribution of the spin-dipole strengths in 16o and neutrino-induced reactions on 16o areinvestigated by shell-model calculations with new shell-model hamiltonians. chargedcurrent and neutral-current reactioncross sections are valuated in various particle and γ emission channels as well as the total ones at neutri... | forbidden transitions in nuclear weak processes relevant to neutrino detection, nucleosynthesis and evolution of stars |
as a key to chemical evolutionary studies, the distribution of elements in galaxies provides a wealth of information to understand their individual star formation histories and detailed chemical enrichment. magnesium and iron are sensitive proxy for the snia and core-collapse sne. r- process elements, such as eu, are c... | 3d non-local thermodynamic equilibrium (nlte) and average three dimensional <3d> models to measure the abundances of fe, mg, eu |
electron-capture and beta -decay rates in stellar environments are evaluated for p-shell, sd-shell and pf-shell nuclei as well as for nuclei in the island of inversion with the use of new shell-model hamiltonians. important roles of the nuclear weak rates on the final evolution of the degenerate cores in stars are pres... | roles of nuclear physics on the final evolution of degenerate cores |
the detection of 1.5-3.2 myr 60-fe on earth indicates recent nearby core-collapse supernovae. for supernovae in multiple stars, the primary stars become neutron stars, while former companions can get unbound (runaway stars). by tracing back the space motion of runaway and neutron stars to the nearest stellar associatio... | a pulsar-runaway-pair from a nearby supernova1.8 myr ago that ejected 60fe found on earth |
even though sne ia are crucial to cosmological studies as distance indicators, the exact nature of these systems remains theoreltically ambiguous and observationally elusive. however, there is a new hope. the very late-time light curves of sne ia harbor important clues to the natures of their progenitor systems. first,... | whimper of a bang: documenting the final days of the nearby type ia supernova 2011fe |
given the limited space in this contribution, it is not possible to go into the details of the exciting astrophysical topic of stellar evolution and nucleosynthesis. it is attempted to emphasize the basics of this basic concept of the hydrostatic evolution of stars as they are driven by the interplay between gravity an... | comments on stellar evolution |
we report new precise abundance determinations for the iron-peak elements (sc-zn) in three metal-poor ([fe/h] ~ -3) stars: bd+03 740, bd-13 3442 and cd-33 1173. these values are based upon new atomic laboratory data (from the wisconsin group) for a number of neutral and ionized species in both the visible and uv wavele... | new precise abundance determinations of the iron-peak elements in three very metal-poor stars |
we examine how well different supernova nucleiosynthesis models are able to fit observed abundances. we test different combinations of published models for core-collapse supernovae, type-ia supernovae, and stellar winds to see how well they can fit solar abundance patterns and observed abundances in the perseus cluster... | fitting observed abundances with supernova nucleosynthesis models |
we present observations of sn 2021csp, the second example of a newly-identified type of supernova (type icn) hallmarked by strong, narrow, p-cygni carbon features. the sn appears as a fast and luminous blue transient at early times early in its evolution, reaching a peak absolute magnitude of -20 within 3 days due to s... | the type icn sn 2021csp: implications for the progenitors of fast/luminous transients and the fates of wolf-rayet stars |
the astrophysical origins of the heaviest stable elements that we observe today in the solar system are still not fully understood. recent studies have demonstrated that h-accreting white dwarfs (wds) in a binary system exploding as type ia supernovae could be an efficient p-process source beyond iron. however, both ob... | slow white dwarf mergers as a new galactic source of trans-iron elements |
studying old, metal-poor stars allows for connecting the present state of the galactic halo with its long-lasting assembly history. by retaining the chemical information from their formation time in their atmospheres, these low-mass (m < 0.8 m_sun) stars also enable the reconstruction of the chemical evolution, earl... | chemical abundances of the most metal-poor stars in the milky way |
the abundances of the fe-peak elements (ti, v, cr, mn, fe, co, and ni) are of interest as they are important for assessing opacities for stellar evolution calculations, confirming theoretical calculations of explosive nucleosynthesis, and inferring the past history of supernova activity in a galaxy. fuse fuv spectra of... | the abundances of the fe group elements in early b stars in the magellanic clouds and our galaxy |
enrichment of the r-process elements is expected to provide a critical clue to understand the formation history of galactic halos. recent astronomical high dispersion observations of metal-poor stars have shown large dispersions in relative abundance ratios of r-process elements such as [eu/fe] in stars with [fe/h] <... | chemo-dynamical evolution model: enrichment of r-process elements in the local group dwarf galaxies |
violent eruptions, and consequently major mass loss, are a common feature of the so-called luminous blue variable (lbv) stars. during major eruptive episodes lbvs mimic the behavior of real type iin supernovae (sne), showing comparable radiated energy and similar spectroscopic properties. for this reason these events a... | interacting supernovae and supernova impostors: evidence of incoming supernova explosions? |
the material used to form the cemp-no stars presents signatures of material processed by the cno cycle and by he-burning from a previous stellar generation called the source stars. in order to reproduce the absolute amounts of cno elements observed at the surface of cemp-no stars ([x/h] values), as well as the relative... | clues about the first stars from cemp-no stars |
we investigate core-collapse supernova (ccsn) nucleosynthesis with axisymmetric simulations using the multidimensional radiation hydrodynamics code chimera. computational costs have traditionally constrained the evolution of the nuclear composition in ccsn models to, at best, a 14-species α-network. such a simplified n... | nucleosynthesis in axisymmetric ab initio core-collapse supernova simulations of 12-25 m⊙ stars |
dwarf galaxies around the milky way halo are ideal laboratory of nucleosynthesis and chemical enrichments in the early universe. we studied chemical compositions including r-process elements for giant stars in draco dwarf spheroidal galaxy based on high-resolution spectra obtained with the subaru/hds. draco is known to... | chemical evolution of r-process elements in draco dwarf spheroidal galaxies |
the synthesis of elements heavier than iron in the early stages of galactic evolution is commonly attributed to type ii (core collapse) supernova explosions. however, the currently accepted mechanisms of heavy element synthesis through neutron capture processes (r-process and s-process) cannot explain the abundance pat... | nuclear reaction rates and their influence on nucleosynthesis in the neutrino-p-process |
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