NEUTRON-RICH CHROMIUM ISOTOPE ANOMALIES IN SUPERNOVA NANOPARTICLES

By Nicolas Dauphas, L. Remusat, James H. Chen, M. Roskosz, D. Papanastassiou, J. Stodolna, Y. Guan, Chi Ma, J. Eiler. 2010

142 citations recorded by the source corpus.

Neutron-rich isotopes with masses near that of iron are produced in Type Ia and II supernovae (SNeIa and SNeII). Traces of such nucleosynthesis are found in primitive meteorites in the form of variations in the isotopic abundance of 54Cr, the most neutron-rich stable isotope of chromium. The hosts of these isotopic anomalies must be presolar grains that condensed in the outflows of SNe, offering the opportunity to study the nucleosynthesis of iron-peak nuclei in ways that complement spectroscopic observations and can inform models of stellar evolution. However, despite almost two decades of extensive search, the carrier of 54Cr anomalies is still unknown, presumably because it is fine grained and is chemically labile. Here, we identify in the primitive meteorite Orgueil the carrier of 54Cr anomalies as nanoparticles (<100 nm), most likely spinels that show large enrichments in 54Cr relative to solar composition (54Cr/52Cr ratio >3.6 × solar). Such large enrichments in 54Cr can only be produced in SNe. The mineralogy of the grains supports condensation in the O/Ne–O/C zones of an SNII, although a Type Ia origin cannot be excluded. We suggest that planetary materials incorporated different amounts of these nanoparticles, possibly due to late injection by a nearby SN that also delivered 26Al and 60Fe to the solar system. This idea explains why the relative abundance of 54Cr and other neutron-rich isotopes vary between planets and meteorites. We anticipate that future isotopic studies of the grains identified here will shed new light on the birth of the solar system and the conditions in SNe.

Subfields: Astronomy and Astrophysics, Radiation, Radiology, Nuclear Medicine and Imaging

View Paper: https://www.semanticscholar.org/paper/1f915a36313b359c4a45e760ea39411b460b1433

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In Astronomy and Astrophysics

1. N. Dauphas
2. F. Ciesla
3. C. Burkhardt
4. L. Nittler
5. T. Kleine
6. A. Morbidelli
7. M. Chaussidon
8. Haolan Tang

In Radiation

1. E. Gaidos

Citations in the corpus

• STELLAR ABUNDANCES IN THE SOLAR NEIGHBORHOOD: THE HYPATIA CATALOG (2014, background): “Chromium, essentially 52Cr, is formed as – 30 – a result of radioactive decay from 52Fe during quasiequilibrium explosive silicon burning (Arnett 1996; Dauphas et al. 2010).”
• Correlated accretion ages and ε54Cr of meteorite parent bodies and the evolution of the solar nebula (2014, background): “Ion probe studies found that small oxide grains are the carrier of the positive (54)Cr anomalies in bulk carbonaceous chondrites (Dauphas et al. 2010; Qin et al. 2011).”
• Astrophysics with Extraterrestrial Materials (2016, background): “Conversely, recent identification of <100-nm oxide grains with large 54Cr (chromium) excesses (Dauphas et al. 2010, Qin et al. 2011) points to the formation of very small grains as well, though reliable O-isotopic measurements are not yet available for these grains.”
• The Non-carbonaceous–Carbonaceous Meteorite Dichotomy (2020, background): “For Cr, one potential carrier of these anomalies has been identified as 54Cr-rich nanospinels that probably condensed in the outflow of supernovae (Dauphas et al. 2010; Qin et al. 2011).”
• Calcium-48 isotopic anomalies in bulk chondrites and achondrites: Evidence for a uniform isotopic reservoir in the inner protoplanetary disk (2014, background): “The carrier of 54Cr isotope anomalies has been identified by NanoSIMS as 54Cr-rich nanooxide/nanospinel grains of supernova origin (Dauphas et al., 2010; Qin et al., 2011).”
• HETEROGENEOUS DISTRIBUTION OF 26Al AT THE BIRTH OF THE SOLAR SYSTEM (2010, methodology): “, after complete delivery of (26)Al carrier(s) to the disk; (2) the (26)Al carrier(s) were rapidly homogenized in the disk; and (3) thermal processing and ⁄or dust-gas fractionation did not result in subsequent heterogeneity of (26)Al in the disk: both processes are being used to explain stable isot”
• EVIDENCE FOR MAGNESIUM ISOTOPE HETEROGENEITY IN THE SOLAR PROTOPLANETARY DISK (2011, background): “…54Cr heterogeneity: an ancient galactic component dominated by input from rare type Ia supernovae (Clayton 2003; Meyer et al. 1996) or, alternatively, heterogeneous seeding of the nascent solar system from a recent event, possibly a nearby massive star (Dauphas et al. 2010; Qin et al. 2011).”
• A Perspective from Extinct Radionuclides on a Young Stellar Object: The Sun and Its Accretion Disk (2011, background): “This idea was proposed to explain 54Cr variations measured in bulk planetary materials because the carrier of these anomalies is very fine grained (<100 nm); it would follow the gas and thus be decoupled easily from coarser grains (Dauphas et al. 2010).”
• NON-RACEMIC AMINO ACID PRODUCTION BY ULTRAVIOLET IRRADIATION OF ACHIRAL INTERSTELLAR ICE ANALOGS WITH CIRCULARLY POLARIZED LIGHT (2011, background): “…and was at some stage processed in such regions is supported by the presence of short-lived isotope products in meteorites coming from a nearby very massive star (Duprat & Tatischeff 2007; Tatischeff et al. 2010; Dauphas et al. 2010), a possibility that has been considered for more than 30 years.”
• Abundance, distribution, and origin of 60Fe in the solar protoplanetary disk (2012, background): “Dauphas et al., 2008). We have measured at high precision the isotopic ratio 58Fe/54Fe in many meteorite groups, and have failed to detect any variation in this isotope (within ±0.5 ε-unit) (Fig. 5). Dauphas et al. (2010) speculated that the 60Fe/56Fe ratio in the solar protoplanetary disk might be ”