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The s-process enrichment of the globular clusters M4 and M22 (2014)
Journal Article
Hirschi. (2014). The s-process enrichment of the globular clusters M4 and M22. Astrophysical Journal, https://doi.org/10.1088/0004-637X/795/1/34

We investigate the enrichment in elements produced by the slow neutron-capture process (s-process) in the globular clusters M4 (NGC 6121) and M22 (NGC 6656). Stars in M4 have homogeneous abundances of Fe and neutron-capture elements, but the entire c... Read More about The s-process enrichment of the globular clusters M4 and M22.

Electron Capture and Beta-Decay Rates for the Collapse of O+Ne+Mg Cores (2014)
Journal Article
Hua Lam, Y., Martínez-Pinedo, G., Langanke, K., Jones, S., Hirschi, R., Zegers, R. G. T., & Alex Brown, B. (2014). Electron Capture and Beta-Decay Rates for the Collapse of O+Ne+Mg Cores. EPJ Web of Conferences, 66, Article 07011. https://doi.org/10.1051/epjconf/20146607011

We present a new set of electron (e−) capture and β-decay rates that improves previous calculations by Takahara et al. and Oda et al. by: (a) incorporation of recent charge-exchange and β-decay data, (b) contributions of forbidden transitions, and (c... Read More about Electron Capture and Beta-Decay Rates for the Collapse of O+Ne+Mg Cores.

Grids of stellar models with rotation - III. Models from 0.8 to 120 Msun at a metallicity Z = 0.002 (2013)
Journal Article
Georgy, C., Ekström, S., Eggenberger, P., Meynet, G., Haemmerlé, L., Maeder, A., …Barblan, F. (2013). Grids of stellar models with rotation - III. Models from 0.8 to 120 Msun at a metallicity Z = 0.002. Astronomy & Astrophysics, 558, Article A103. https://doi.org/10.1051/0004-6361/201322178

(shortened) We provide a grid of single star models covering a mass range from 0.8 to 120 Msun with an initial metallicity Z = 0.002 with and without rotation. We discuss the impact of a change in the metallicity by comparing the current tracks with... Read More about Grids of stellar models with rotation - III. Models from 0.8 to 120 Msun at a metallicity Z = 0.002.

ADVANCED BURNING STAGES AND FATE OF 8-10M☉STARS (2013)
Journal Article
Jones, S., Hirschi, R., Nomoto, K., Fischer, T., Timmes, F. X., Herwig, F., …Bertolli, M. G. (in press). ADVANCED BURNING STAGES AND FATE OF 8-10M☉STARS. Astrophysical Journal, 772(2), 150. https://doi.org/10.1088/0004-637x/772/2/150

The reaction of either 4,4′,6,6′-tetramethyl-2,2′-bipyridine, L, or 4,4′,6,6′-tetracarboxy-2,2′-bipyridine, H4L, with Cu(OAc)2·H2O under acidic hydrothermal conditions (50:1 H2O/HNO3; 160 °C) led to the formation of crystalline {[Cu(HL′)(H2O)]·H2O},... Read More about ADVANCED BURNING STAGES AND FATE OF 8-10M☉STARS.

Detailedβ-transition rates for URCA nuclear pairs in 8–10 solar-mass stars (2013)
Journal Article
Toki, H., Suzuki, T., Nomoto, K., Jones, S., & Hirschi, R. Detailedβ-transition rates for URCA nuclear pairs in 8–10 solar-mass stars. Physical Review C - Nuclear Physics, 88(1), Article 015806. https://doi.org/10.1103/physrevc.88.015806

We calculate β-transition rates for URCA nuclear pairs using the sd-shell-model framework of Wildenthal [B. H. Widenthal, Prog. Part. Nucl. Phys. 11, 5 (1984)] with the modified Hamiltonian. We consider many β transitions including excited states nec... Read More about Detailedβ-transition rates for URCA nuclear pairs in 8–10 solar-mass stars.

SILICON CARBIDE GRAINS OF TYPE C PROVIDE EVIDENCE FOR THE PRODUCTION OF THE UNSTABLE ISOTOPE 32 Si IN SUPERNOVAE (2013)
Journal Article
Pignatari, M., Zinner, E., Bertolli, M. G., Trappitsch, R., Hoppe, P., Rauscher, T., …Thielemann, F. (in press). SILICON CARBIDE GRAINS OF TYPE C PROVIDE EVIDENCE FOR THE PRODUCTION OF THE UNSTABLE ISOTOPE 32 Si IN SUPERNOVAE. Astrophysical Journal Letters, 771(1), L7. https://doi.org/10.1088/2041-8205/771/1/l7

Carbon-rich grains are observed to condense in the ejecta of recent core-collapse supernovae (SNe) within a year after the explosion. Silicon carbide grains of type X are C-rich grains with isotopic signatures of explosive SN nucleosynthesis have bee... Read More about SILICON CARBIDE GRAINS OF TYPE C PROVIDE EVIDENCE FOR THE PRODUCTION OF THE UNSTABLE ISOTOPE 32 Si IN SUPERNOVAE.

Evolution and fate of very massive stars (2013)
Journal Article
Yusof, N., Hirschi, R., Meynet, G., Crowther, P. A., Ekström, S., Frischknecht, U., …Schnurr, O. (2013). Evolution and fate of very massive stars. Monthly Notices of the Royal Astronomical Society, 433(2), 1114-1132. https://doi.org/10.1093/mnras/stt794

There is observational evidence that supports the existence of Very Massive Stars in the local universe. First, very massive stars (Mini

Thes-process in the Galactic halo: the fifth signature of spinstars in the early Universe? (2013)
Journal Article
Cescutti, G., Chiappini, C., Hirschi, R., Meynet, G., & Frischknecht, U. (2013). Thes-process in the Galactic halo: the fifth signature of spinstars in the early Universe?. Astronomy & Astrophysics, 553, Article A51. https://doi.org/10.1051/0004-6361/201220809

Context. Very old halo stars have previously been found to show at least four different abundance anomalies, which models of fast-rotating massive stars (spinstars) can successfully account for: rise of N/O and C/O, low 12C/13C, and a primary-like ev... Read More about Thes-process in the Galactic halo: the fifth signature of spinstars in the early Universe?.

PRODUCTION OF CARBON-RICH PRESOLAR GRAINS FROM MASSIVE STARS (2013)
Journal Article
Pignatari, M., Wiescher, M., Timmes, F. X., de Boer, R. J., Thielemann, F., Fryer, C., …Hirschi, R. (in press). PRODUCTION OF CARBON-RICH PRESOLAR GRAINS FROM MASSIVE STARS. Astrophysical Journal Letters, 767(2), L22. https://doi.org/10.1088/2041-8205/767/2/l22

About a year after core-collapse supernova, dust starts to condense in the ejecta. In meteorites, a fraction of C-rich presolar grains (e.g., silicon carbide (SiC) grains of Type-X and low density graphites) are identified as relics of these events,... Read More about PRODUCTION OF CARBON-RICH PRESOLAR GRAINS FROM MASSIVE STARS.