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 as presolar grain studies. Our non-rotating models assume convective boundary mixing (CBM) where it has been adopted before. We include 8 (12) initial masses for Z = 0.01 (0.02). Models are followed either until the end of the asymptotic giant branch phase or the end of Si burning, complemented by simple analytic core-collapse supernova (SN) models with two options for fallback and shock velocities. The explosions show which pre-SN yields will most strongly be effected by the explosive nucleosynthesis. We discuss how these two explosion parameters impact the light elements and the s and p process. For low-and intermediate-mass models, our stellar yields from H to Bi include the effect of CBM at the He-intershell boundaries and the stellar evolution feedback of the mixing process that produces the C 13 pocket. All post-processing nucleosynthesis calculations use the same nuclear reaction rate network and nuclear physics input. We provide a discussion of the nuclear production across the entire mass range organized by element group. The entirety of our stellar nucleosynthesis profile and time evolution output are available electronically, and tools to explore the data on the NuGrid VOspace hosted by the Canadian Astronomical Data Centre are introduced.

The s-process nucleosynthesis in Asymptotic Giant Branch (AGB) stars depends on the modeling of convective boundaries. We present models and s-process simulations that adopt a treatment of convective boundaries based on the results of hydrodynamic simulations and on the theory of mixing due to gravity waves in the vicinity of convective boundaries. Hydrodynamics simulations suggest the presence of convective boundary mixing (CBM) at the bottom of the thermal pulse-driven convective zone. Similarly, convection-induced mixing processes are proposed for the mixing below the convective envelope during third dredge-up where the 13 C pocket for the s process in AGB stars forms. In this work we apply a CBM model motivated by simulations and theory to models with initial mass M = 2 and M = 3M , and with initial metal content Z = 0.01 and Z = 0.02. As reported previously, the He-intershell abundance of 12 C and 16 O are increased by CBM at the bottom of pulse-driven convection zone. This mixing is affecting the 22 Ne(α,n) 25 Mg activation and the s-process efficiency in the 13 C-pocket. In our model CBM at the bottom of the convective envelope during the third dredgeup represents gravity wave mixing. We take further into account that hydrodynamic simulations indicate a declining mixing efficiency already about a pressure scale height from the convective boundaries, compared to mixing-length theory. We obtain the formation of the 13 C-pocket with a mass of ≈ 10 −4 M . The final s-process abundances are characterized by 0.36 < [s/Fe] < 0.78 and the heavy-to-light s-process ratio is −0.23 < [hs/ls] < 0.45. Finally, we compare our results with stellar observations, pre-solar grain measurements and previous work.

We present noble gas data for 16 shergottites, 2 nakhlites (NWA 5790, NWA 10153), and 1 angrite (NWA 7812). Noble gas exposure ages of the shergottites fall in the 1–6 Ma range found in previous studies. Three depleted olivine‐phyric shergottites (Tissint, NWA 6162, NWA 7635) have exposure ages of ~1 Ma, in agreement with published data for similar specimens. The exposure age of NWA 10153 (~12.2 Ma) falls in the range of 9–13 Ma reported for other nakhlites. Our preferred age of ~7.3 Ma for NWA 5790 is lower than this range, and it is possible that NWA 5790 represents a distinct ejection event. A Tissint glass sample contains Xe from the Martian atmosphere. Several samples show a remarkably low (21Ne/22Ne)cos ratio < 0.80, as previously observed in a many shergottites and in various other rare achondrites. This was explained by solar cosmic ray‐produced Ne (SCR Ne) in addition to the commonly found galactic cosmic ray‐produced Ne, implying very low preatmospheric shielding and ablation loss. We revisit this by comparing measured (21Ne/22Ne)cos ratios with predictions by cosmogenic nuclide production models. Indeed, several shergottites, acalpulcoites/lodranites, angrites (including NWA 7812), and the Brachina‐like meteorite LEW 88763 likely contain SCR Ne, as previously postulated for many of them. The SCR contribution may influence the calculation of exposure ages. One likely reason that SCR nuclides are predominantly detected in meteorites from rare classes is because they usually are analyzed for cosmogenic nuclides even if they had a very small (preatmospheric) mass and hence low ablation loss.

The metamorphic history of martian meteorite NWA 7034 suggests that the martian crustal dichotomy may have formed within 100 million years of planetary formation.

Carbon-rich grains with isotopic anomalies compared to the Sun are found in primitive meteorites. They were made by stars, and carry the original stellar nucleosynthesis signature. Silicon carbide grains of Type X and C and low-density (LD) graphites condensed in the ejecta of core-collapse supernovae. We present a new set of models for the explosive He shell and compare them with the grains showing 12 C/ 13 C and 14 N/ 15 N ratios lower than solar. In the stellar progenitor H was ingested into the He shell and not fully destroyed before the explosion. Different explosion energies and H concentrations are considered. If the supernova shock hits the He-shell region with some H still present, the models can reproduce the C and N isotopic signatures in C-rich grains. Hot-CNO cycle isotopic signatures are obtained, including a large production of 13 C and 15 N. The short-lived radionuclides 22 Na and 26 Al are increased by orders of magnitude. The production of radiogenic 22 Ne from the decay of 22 Na in the He shell might solve the puzzle of the Ne-E(L) component in LD graphite grains. This scenario is attractive for the SiC grains of type AB with 14 N/ 15 N ratios lower than solar, and provides an alternative solution for SiC grains originally classified as nova grains. Finally, this process may contribute to the production of 14 N and 15 N in the Galaxy, helping to produce the 14 N/ 15 N ratio in the solar system.

Graphi cal Abstract 3 Highlights• CHILI is a new resonance ionization mass spectrometer at the University of Chicago • CHILI has been developed for isotopic analysis of small samples in cosmochemistry • CHILI combines high spatial resolution and high sensitivity • Sr, Ba, Fe, and Ni isotopes have been measured in presolar grains • A new timing scheme allows analysis of all Fe and Ni isotopes without interferences 4 ABSTRACT We describe CHILI, the Chicago Instrument for Laser Ionization, a new resonance ionization mass spectrometer developed for isotopic analysis at high spatial resolution and high sensitivity of small samples like contemporary interstellar dust grains returned by the Stardust spacecraft. We explain how CHILI addresses the technical challenges associated with such analyses by pushing most technical specifications towards their physical limits. As an initial demonstration, after many years of designing and developing CHILI, we have analyzed presolar silicon carbide grains for their isotopic compositions of strontium, zirconium, and barium. Subsequently, after further technical improvements, we have used CHILI to analyze, for the first time without interference, all stable isotopes of iron and nickel simultaneously in presolar silicon carbide grains. With a special timing scheme for the ionization lasers, we separated iron and nickel isotopes in the time-of-flight spectrum such that the isobaric interference between 58 Fe and 58 Ni was resolved. In-depth discussion of the astrophysical implications of the presolar grain results is deferred to dedicated later publications. Here we focus on the technical aspects of CHILI, its status quo, and further developments necessary to achieve CHILI's ultimate goals, ~10 nm lateral resolution and 30-40 % useful yield.

The production of the neutron-capture isotopes beyond iron that we observe today in the Solar system is the result of the combined contribution of the r-process, the s-process, and possibly the i-process. Low-mass asymptotic giant branch (AGB) (1.5 < M/M⊙ < 3) and massive (M > 10 M⊙) stars have been identified as the main site of the s-process. In this work we consider the evolution and nucleosynthesis of low-mass AGB stars. We provide an update of the NuGrid Set models, adopting the same general physics assumptions but using an updated convective-boundary-mixing model accounting for the contribution from internal gravity waves. The combined data set includes the initial masses MZAMS/M⊙ = 2, 3 for Z = 0.03, 0.02, 0.01. These new models are computed with the mesa stellar code and the evolution is followed up to the end of the AGB phase. The nucleosynthesis was calculated for all isotopes in post-processing with the NuGrid mppnp code. The convective-boundary-mixing model leads to the formation of a 13C-pocket three times wider compared to the one obtained in the previous set of models, bringing the simulation results now in closer agreement with observations. Using these new models, we discuss the potential impact of other processes inducing mixing, like rotation, adopting parametric models compatible with theory and observations. Complete yield data tables, derived data products, and online analytic data access are provided.

Classical novae are the results of surface thermonuclear explosions of hydrogen accreted by white dwarfs (WDs) from their low-mass main-sequence or redgiant binary companions. Chemical composition analysis of their ejecta shows that nova outbursts occur on both carbon-oxygen (CO) and more massive oxygen-neon (ONe) WDs, and that there is cross-boundary mixing between the accreted envelope and underlying WD. We demonstrate that the state-of-the-art stellar evolution code MESA and post-processing nucleosynthesis tools of NuGrid can successfully be used for modeling of CO and ONe nova outbursts and nucleosynthesis. The convective boundary mixing (CBM) in our 1D numerical simulations is implemented using a diffusion coefficient that is exponentially decreasing with a distance below the bottom of the convective envelope. We show that this prescription produces maximum temperature evolution profiles and nucleosynthesis yields in good agreement with those obtained using the commonly adopted 1D nova model in which the CBM is mimicked by assuming that the accreted envelope has been pre-mixed with WD's material. In a previous paper, we have found that 3 He can be produced in situ in solar-composition envelopes accreted with slow rates (Ṁ < 10 −10 M ⊙ /yr) by cold (T WD < 10 7 K) CO WDs, and that convection is triggered by 3 He burning before the nova outburst in this case. Here, we confirm this result for ONe novae. Additionally, we find that the interplay between the 3 He production and destruction in the solar-composition envelope accreted with an intermediate rate, e.g.Ṁ = 10 −10 M ⊙ /yr, by the 1.15 M ⊙ ONe WD with a relatively high initial central temperature, e.g. T WD = 15 ×10 6 K, leads to the formation of a thick radiative buffer zone that separates the bottom of the convective envelope from the WD surface.