Presolar Grains & Meteorites Peter Hoppe Max Planck Institute for Chemistry, Mainz Workshop on Nuclear Astrophysics in Germany Darmstadt, November 15/16, 2016

Introduction (I) Introduction Techniques Isotopes Prospects Isotopic studies are important tools in cosmochemical research Extraterrestrial material with high relevance for nuclear astrophysics: Presolar grains Presolar grains: nm- to mm-sized refractory grains Found in small quantities in primitive meteorites, IDPs, and cometary matter Older than our Solar System Formation in the winds of evolved stars or in the ejecta of stellar explosions Large isotopic anomalies MPI for Chemistry Particle Chem. Dep.

Presolar Grains: Path from Stars to the Laboratory Introduction (II) Introduction Techniques Isotopes Prospects Presolar Grains: Path from Stars to the Laboratory MPI for Chemistry Particle Chem. Dep.

Introduction (III) Introduction Techniques Isotopes Prospects MPI for Chemistry Particle Chem. Dep.

Supernova Grains from Meteorites Introduction (IV) Introduction Techniques Isotopes Prospects Supernova Grains from Meteorites SiC X MPIC SiC C MPIC Hibonite L. Nittler Graphite S. Amari MPI for Chemistry Particle Chem. Dep.

Astrophysical Information Introduction (V) Introduction Techniques Isotopes Prospects Astrophysical Information Stellar nucleosynthesis und evolution Mixing in SN ejecta Galactic chemical evolution Circumstellar dust formation Chemical and physical processes in the ISM Types of stars that contributed dust to the Solar System MPI for Chemistry Particle Chem. Dep.

Measurement Techniques Techniques (I) Introduction Techniques Isotopes Prospects Measurement Techniques Secondary Ion Mass Spectrometry (SIMS) Resonance Ionization Mass Spectrometry (RIMS) Focused Ion Beam (FIB) / Transmission Electron Microscopy (TEM) Atom Probe Tomography (APT) MPI for Chemistry Particle Chem. Dep.

Techniques (II) NanoSIMS Ion Probe Introduction Techniques Isotopes Prospects NanoSIMS Ion Probe Permits isotope measurements with high spatial resolution (down to 50 nm) High useful yields (detected ions/sputtered atoms) up to the % range for certain elements Simultaneous detection of up to 7 isotopes Ion imaging capabilities MPI for Chemistry Particle Chem. Dep.

Isotope Measurements (I) Introduction Techniques Isotopes Prospects C and N Isotopes in Presolar SiC Mainstream (90%): 1.5-3 M AGB stars, solar metallicity Type Y & Z (a few %): 1.5-3 M AGB stars, sub-solar metallicity Nova ( 0.1%) Type A & B (a few %): J-type C stars Born-again AGB stars Supernovae Type X & C (1-2%): Supernovae MPI for Chemistry Particle Chem. Dep. (Data source: WU Presolar Grain Data Base)

Isotope Measurements (II) Introduction Techniques Isotopes Prospects Silicon Isotopes in Presolar SiC Open Issues: Heavy Si + heavy C in SN C grains? Si component with d29Si = -800 ‰ and d30Si = -1000 ‰ Why have MS and AB grains the same Si systematics? Origin of “Nova” grains? MPI for Chemistry Particle Chem. Dep. (Data source: WU Presolar Grain Data Base)

Isotope Measurements (III) Introduction Techniques Isotopes Prospects Supernova Models MPI for Chemistry Particle Chem. Dep. Pignatari et al. (2015)

Isotope Measurements (IV) Introduction Techniques Isotopes Prospects O Isotopes in Presolar Oxides and Silicates Open Issues: Why so few 16O-rich SN grains? How to produce 18O-rich oxide/silicate SN grains? MPI for Chemistry Particle Chem. Dep. (Data source: WU Presolar Grain Data Base)

Analytical Approaches Future Prospects (I) Introduction Techniques Isotopes Prospects Analytical Approaches NanoSIMS ion imaging: Find rare grains for in-depth isotope studies (e.g., SiC SN and nova grains) CHILI (improved RIMS instrument) at University of Chicago: Measure isotopic compositions of heavy elements with high spatial resolution (<50 nm) Atom probe tomography for isotope & elemental abundance studies at even smaller scales? MPI for Chemistry Particle Chem. Dep.

Presolar Grains in Context of Nuclear Astrophysics Future Prospects (II) Introduction Techniques Isotopes Prospects Presolar Grains in Context of Nuclear Astrophysics Stimulate measurement of specific nuclear reaction rates (e.g., Si production in SNe) Nucleosynthetic constraints for stellar models (e.g. new Pignatari SN models) How to produce dust in SN environments Astronomical observations: Which dust types in SN ejecta? MPI for Chemistry Particle Chem. Dep.