All Outputs (123)

3D simulations of convective shell Neon-burning in a massive star (2024)
Journal Article
Georgy, C., Rizzuti, F., Hirschi, R., Varma, V., Arnett, W. D., Meakin, C., …Rauscher, T. (in press). 3D simulations of convective shell Neon-burning in a massive star. Monthly Notices of the Royal Astronomical Society, 531(4), 4293–4310. https://doi.org/10.1093/mnras/stae1381

The treatment of convection remains a major weakness in the modelling of stellar evolution with one-dimensional (1D) codes. The ever increasing computing power makes now possible to simulate in 3D part of a star for a fraction of its life, allowing u... Read More about 3D simulations of convective shell Neon-burning in a massive star.

Experimental Determination of α Widths of ^{21}Ne Levels in the Region of Astrophysical Interest: New ^{17}O+α Reaction Rates and Impact on the Weak s Process. (2024)
Journal Article
Hammache, F., Adsley, P., Lamia, L., Harrouz, D. S., de Séréville, N., Bastin, B., …Wirth, H.-F. (2024). Experimental Determination of α Widths of ^{21}Ne Levels in the Region of Astrophysical Interest: New ^{17}O+α Reaction Rates and Impact on the Weak s Process. Physical Review Letters, 132(18), Article 182701. https://doi.org/10.1103/PhysRevLett.132.182701

The efficiency of the weak s process in low-metallicity rotating massive stars depends strongly on the rates of the competing ^{17}O(α,n)^{20}Ne and ^{17}O(α,γ)^{21}Ne reactions that determine the potency of the ^{16}O neutron poison. Their reaction... Read More about Experimental Determination of α Widths of ^{21}Ne Levels in the Region of Astrophysical Interest: New ^{17}O+α Reaction Rates and Impact on the Weak s Process..

Very massive star models: I. Impact of rotation and metallicity and comparisons with observations (2023)
Journal Article
Martinet, S., Meynet, G., Ekström, S., Georgy, C., & Hirschi, R. (2023). Very massive star models: I. Impact of rotation and metallicity and comparisons with observations. Astronomy & Astrophysics, 679, Article A137. https://doi.org/10.1051/0004-6361/202347514

Context. In addition to being spectacular objects, very massive stars (VMSs) are suspected to have a tremendous impact on their environment and on cosmic evolution in general. The nucleosynthesis both during their advanced stages and their final expl... Read More about Very massive star models: I. Impact of rotation and metallicity and comparisons with observations.

The Nuclear Reaction Network WinNet (2023)
Journal Article
Reichert, M., Winteler, C., Korobkin, O., Arcones, A., Bliss, J., Eichler, M., …Thielemann, F. (2023). The Nuclear Reaction Network WinNet. The Astrophysical Journal Supplement, 268(2), Article 66. https://doi.org/10.3847/1538-4365/acf033

We present the state-of-the-art single-zone nuclear reaction network WinNet, which is capable of calculating the nucleosynthetic yields of a large variety of astrophysical environments and conditions. This ranges from the calculation of the primordia... Read More about The Nuclear Reaction Network WinNet.

Slow Neutron-Capture Process in Evolved Stars (2023)
Book Chapter
Hirschi, R. (2023). Slow Neutron-Capture Process in Evolved Stars. In Handbook of Nuclear Physics (3537-3571). Springer. https://doi.org/10.1007/978-981-19-6345-2_118

The slow neutron-capture process (s process) contributes to the production of roughly half of the elements heavier than iron. The main component of the s process takes place in the late phases (AGB phase) of low-mass stars and is the topic of most re... Read More about Slow Neutron-Capture Process in Evolved Stars.

Stellar wind yields of very massive stars (2023)
Journal Article
Higgins, E. R., Vink, J. S., Hirschi, R., Laird, A. M., & Sabhahit, G. N. (in press). Stellar wind yields of very massive stars. Monthly Notices of the Royal Astronomical Society, 526(1), 534–547. https://doi.org/10.1093/mnras/stad2537

The most massive stars provide an essential source of recycled material for young clusters and galaxies. While very massive stars (VMS, M>100 $\rm {\rm M}_{\odot }$) are relatively rare compared to O stars, they lose disproportionately large a... Read More about Stellar wind yields of very massive stars.

3D stellar evolution: hydrodynamic simulations of a complete burning phase in a massive star (2023)
Journal Article
Rizzuti, F., Hirschi, R., Arnett, W. D., Georgy, C., Meakin, C., Murphy, A. S., …Varma, V. (2023). 3D stellar evolution: hydrodynamic simulations of a complete burning phase in a massive star. Monthly Notices of the Royal Astronomical Society, 523(2), 2317-2328. https://doi.org/10.1093/mnras/stad1572

Our knowledge of stellar evolution is driven by one-dimensional (1D) simulations. 1D models, however, are severely limited by uncertainties on the exact behaviour of many multidimensional phenomena occurring inside stars, affecting their structure an... Read More about 3D stellar evolution: hydrodynamic simulations of a complete burning phase in a massive star.

Turbulence and nuclear reactions in 3D hydrodynamics simulations of massive stars (2023)
Journal Article
Rizzuti, F., Hirschi, R., Georgy, C., Arnett, D., Meakin, C., & Murphy, A. (2023). Turbulence and nuclear reactions in 3D hydrodynamics simulations of massive stars. EPJ Web of Conferences, 279, 05001. https://doi.org/10.1051/epjconf/202327905001

Our knowledge of massive star evolution and nucleosynthesis is limited by uncertainties related to multi-dimensional processes taking place in stellar interiors. Recently, theoretical works have started to improve 1D stellar evolution codes through t... Read More about Turbulence and nuclear reactions in 3D hydrodynamics simulations of massive stars.

The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at Solar, LMC, and SMC metallicities (2022)
Journal Article
Keszthelyi, Z., de Koter, A., Götberg, Y., Meynet, G., Brands, S. A., Petit, V., …ud-Doula, A. (2022). The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at Solar, LMC, and SMC metallicities. Monthly Notices of the Royal Astronomical Society, 517(2), 2028 - 2055. https://doi.org/10.1093/mnras/stac2598

Magnetic fields can drastically change predictions of evolutionary models of massive stars via mass-loss quenching, magnetic braking, and efficient angular momentum transport, which we aim to quantify in this work. We use the MESA software instrument... Read More about The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at Solar, LMC, and SMC metallicities.

Very massive star winds as sources of the short-lived radioactive isotope Al-26 (2022)
Journal Article
Hirschi. (2022). Very massive star winds as sources of the short-lived radioactive isotope Al-26. Astronomy & Astrophysics,

Context. The 26Al short-lived radioactive nuclide is the source of the observed galactic diffuse ?-ray emission at 1.8 MeV. While different sources of 26Al have been explored, such as asymptotic giant branch stars, massive stellar winds, and supernov... Read More about Very massive star winds as sources of the short-lived radioactive isotope Al-26.

Very massive star winds as sources of the short-lived radioactive isotope 26Al (2022)
Journal Article
Martinet, S., Meynet, G., Nandal, D., Ekström, S., Georgy, C., Haemmerlé, L., …Dwarkadas, V. (2022). Very massive star winds as sources of the short-lived radioactive isotope 26Al. Astronomy & Astrophysics, 664, A181. https://doi.org/10.1051/0004-6361/202243474

Context. The 26Al short-lived radioactive nuclide is the source of the observed galactic diffuse γ-ray emission at 1.8 MeV. While different sources of 26Al have been explored, such as asymptotic giant branch stars, massive stellar winds, and supernov... Read More about Very massive star winds as sources of the short-lived radioactive isotope 26Al.

Realistic 3D hydrodynamics simulations find significant turbulent entrainment in massive stars (2022)
Journal Article
Rizzuti, F., Hirschi, R., Georgy, C., Arnett, W. D., Meakin, C., & Murphy, A. S. (2022). Realistic 3D hydrodynamics simulations find significant turbulent entrainment in massive stars. Monthly Notices of the Royal Astronomical Society, 515(3), 4013-4019. https://doi.org/10.1093/mnras/stac1981

Our understanding of stellar structure and evolution coming from one-dimensional (1D) stellar models is limited by uncertainties related to multidimensional processes taking place in stellar interiors. 1D models, however, can now be tested and improv... Read More about Realistic 3D hydrodynamics simulations find significant turbulent entrainment in massive stars.

The impact of O-17 + alpha reaction rate uncertainties on the s-process in rotating massive stars (2022)
Journal Article
Frost-Schenk, J., Adsley, P., Laird, A. M., Longland, R., Angus, C., Barton, C., …Setoodehnia, K. (2022). The impact of O-17 + alpha reaction rate uncertainties on the s-process in rotating massive stars. Monthly Notices of the Royal Astronomical Society, 514(2), 2650 - 2657. https://doi.org/10.1093/mnras/stac1373

Massive stars are crucial to galactic chemical evolution for elements heavier than iron. Their contribution at early times in the evolution of the Universe, however, is unclear due to poorly constrained nuclear reaction rates. The competing 17O(a, ?)... Read More about The impact of O-17 + alpha reaction rate uncertainties on the s-process in rotating massive stars.

The p-process in exploding rotating massive stars (2022)
Journal Article
Choplin, A., Goriely, S., Hirschi, R., Tominaga, N., & Meynet, G. (2022). The p-process in exploding rotating massive stars. Astronomy & Astrophysics, 661, Article A86. https://doi.org/10.1051/0004-6361/202243331

Context. The p-process nucleosynthesis can explain proton-rich isotopes that are heavier than iron, which are observed in the Solar System, but discrepancies still persist (e.g. for the Mo and Ru p-isotopes), and some important questions concerning t... Read More about The p-process in exploding rotating massive stars.

Dynamics in a stellar convective layer and at its boundary: Comparison of five 3D hydrodynamics codes (2022)
Journal Article
Andrassy, R., Higl, J., Mao, H., Mocak, M., Vlaykov, D. G., Arnett, W. D., …Woodward, P. (2022). Dynamics in a stellar convective layer and at its boundary: Comparison of five 3D hydrodynamics codes. Astronomy & Astrophysics, 659, Article ARTN A193. https://doi.org/10.1051/0004-6361/202142557

Our ability to predict the structure and evolution of stars is in part limited by complex, 3D hydrodynamic processes such as convective boundary mixing. Hydrodynamic simulations help us understand the dynamics of stellar convection and convective bou... Read More about Dynamics in a stellar convective layer and at its boundary: Comparison of five 3D hydrodynamics codes.

Grids of stellar models with rotation VII: models from 0.8 to 300 M-circle dot at supersolar metallicity (Z=0.020) (2022)
Journal Article
Yusof, N., Hirschi, R., Eggenberger, P., Ekström, S., Georgy, C., Sibony, Y., …Murphy, L. (2022). Grids of stellar models with rotation VII: models from 0.8 to 300 M-circle dot at supersolar metallicity (Z=0.020). Monthly Notices of the Royal Astronomical Society, 511(2), 2814 - 2828. https://doi.org/10.1093/mnras/stac230

We present a grid of stellar models at supersolar metallicity (Z = 0.020) extending the previous grids of Geneva models at solar and sub-solar metallicities. A metallicity of Z = 0.020 was chosen to match that of the inner Galactic disc. A modest inc... Read More about Grids of stellar models with rotation VII: models from 0.8 to 300 M-circle dot at supersolar metallicity (Z=0.020).

UVES analysis of red giants in the bulge globular cluster NGC 6522 (2021)
Journal Article
Hirschi. (2021). UVES analysis of red giants in the bulge globular cluster NGC 6522. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202140815

Context. NGC 6522 is a moderately metal-poor bulge globular cluster ([Fe/H] ~ -1.0), and it is a well-studied representative among a number of moderately metal-poor blue horizontal branch clusters located in the bulge. The NGC 6522 abundance pattern... Read More about UVES analysis of red giants in the bulge globular cluster NGC 6522.

Multidimensional low-Mach number time-implicit hydrodynamic simulations of convective helium shell burning in a massive star (2021)
Journal Article
Hirschi. (2021). Multidimensional low-Mach number time-implicit hydrodynamic simulations of convective helium shell burning in a massive star. Astronomy & Astrophysics, 1-24. https://doi.org/10.1051/0004-6361/202140825

Context. A realistic parametrization of convection and convective boundary mixing in conventional stellar evolution codes is still the subject of ongoing research. To improve the current situation, multidimensional hydrodynamic simulations are used t... Read More about Multidimensional low-Mach number time-implicit hydrodynamic simulations of convective helium shell burning in a massive star.

Grids of stellar models with rotation: VI. Models from 0.8 to 120 M⊙ at a metallicity Z = 0.006 (2021)
Journal Article
Eggenberger, P., Ekström, S., Georgy, C., Martinet, S., Pezzotti, C., Nandal, D., …Choplin, A. (2021). Grids of stellar models with rotation: VI. Models from 0.8 to 120 M⊙ at a metallicity Z = 0.006. Astronomy & Astrophysics, 652, Article A137. https://doi.org/10.1051/0004-6361/202141222

Context. Grids of stellar models, computed with the same physical ingredients, allow one to study the impact of a given physics on a broad range of initial conditions and they are a key ingredient for modeling the evolution of galaxies. Aims. We p... Read More about Grids of stellar models with rotation: VI. Models from 0.8 to 120 M⊙ at a metallicity Z = 0.006.

Grids of stellar models with rotation VI. Models from 0.8 to 120 M-circle dot at a metallicity Z=0.006 (2021)
Journal Article
Hirschi. (2021). Grids of stellar models with rotation VI. Models from 0.8 to 120 M-circle dot at a metallicity Z=0.006. Astronomy & Astrophysics,

Context. Grids of stellar models, computed with the same physical ingredients, allow one to study the impact of a given physics on a broad range of initial conditions and they are a key ingredient for modeling the evolution of galaxies. Aims. We p... Read More about Grids of stellar models with rotation VI. Models from 0.8 to 120 M-circle dot at a metallicity Z=0.006.