Outputs (104)

The s process in rotating low-mass AGB stars - Nucleosynthesis calculations in models matching asteroseismic constraints (2019)
Journal Article
Hirschi. (2019). The s process in rotating low-mass AGB stars - Nucleosynthesis calculations in models matching asteroseismic constraints. Astronomy and Astrophysics, A123 -A123. https://doi.org/10.1051/0004-6361/201935476

Aims We investigate the s-process during the AGB phase of stellar models whose cores are enforced to rotate at rates consistent with asteroseismology observations of their progenitors and successors. Methods We calculated new 2 M?, Z = 0.01 mode... Read More about The s process in rotating low-mass AGB stars - Nucleosynthesis calculations in models matching asteroseismic constraints.

The contribution from rotating massive stars to the enrichment in Sr and Ba of the Milky Way (2019)
Journal Article
Rizzuti, F., Cescutti, G., Matteucci, F., Chieffi, A., Hirschi, R., & Limongi, M. (2019). The contribution from rotating massive stars to the enrichment in Sr and Ba of the Milky Way. Monthly Notices of the Royal Astronomical Society, 489(4), 5244 -5255. https://doi.org/10.1093/mnras/stz2505

Most neutron capture elements have a double production by r- and s-processes, but the question of production sites is complex and still open. Recent studies show that including stellar rotation can have a deep impact on nucleosynthesis. We studied th... Read More about The contribution from rotating massive stars to the enrichment in Sr and Ba of the Milky Way.

A direct measurement of the 17O(a,?)21Ne reaction in inverse kinematics and its impact on heavy element production (2019)
Journal Article
Taggart, M., Akers, C., Laird, A., Hager, U., Ruiz, C., Hutcheon, D., …Williams, M. (2019). A direct measurement of the 17O(a,?)21Ne reaction in inverse kinematics and its impact on heavy element production. Physics Letters B, 798(10), Article 134894. https://doi.org/10.1016/j.physletb.2019.134894

During the slow neutron capture process in massive stars, reactions on light elements can both produce and absorb neutrons thereby influencing the final heavy element abundances. At low metallicities, the high neutron capture rate of 16O can inhibit... Read More about A direct measurement of the 17O(a,?)21Ne reaction in inverse kinematics and its impact on heavy element production.

3D Simulations and MLT. I. Renzini’s Critique (2019)
Journal Article
Arnett, W. D., Meakin, C., Hirschi, R., Cristini, A., Georgy, C., Campbell, S., …Mocák, M. (2019). 3D Simulations and MLT. I. Renzini’s Critique. Astrophysical Journal, 882(1), 18. https://doi.org/10.3847/1538-4357/ab21d9

Renzini wrote an influential critique of “overshooting” in mixing-length theory (MLT), as used in stellar evolution codes, and concluded that three-dimensional fluid dynamical simulations were needed. Such simulations are now well tested. Implicit la... Read More about 3D Simulations and MLT. I. Renzini’s Critique.

NuGrid stellar data set – III. Updated low-mass AGB models and s-process nucleosynthesis with metallicities Z= 0.01, Z = 0.02, and Z = 0.03 (2019)
Journal Article
Battino, U., Tattersall, A., Lederer-Woods, C., Herwig, F., Denissenkov, P., Hirschi, R., …Collaboration, T. N. (2019). NuGrid stellar data set – III. Updated low-mass AGB models and s-process nucleosynthesis with metallicities Z= 0.01, Z = 0.02, and Z = 0.03. Monthly Notices of the Royal Astronomical Society, 489(1), 1082 -1098. https://doi.org/10.1093/mnras/stz2158

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 &... Read More about NuGrid stellar data set – III. Updated low-mass AGB models and s-process nucleosynthesis with metallicities Z= 0.01, Z = 0.02, and Z = 0.03.

Uncertainties in νp-process nucleosynthesis from Monte Carlo variation of reaction rates (2019)
Journal Article
Nishimura (西村信哉), N., Rauscher, T., Hirschi, R., Hirschi, R., Cescutti, G., Murphy, A. S. J., & Fröhlich, C. (2019). Uncertainties in νp-process nucleosynthesis from Monte Carlo variation of reaction rates. Monthly Notices of the Royal Astronomical Society, 489(1), 1379-1396. https://doi.org/10.1093/mnras/stz2104

It has been suggested that a ?p process can occur when hot, dense, and proton-rich matter is expanding within a strong flux of anti-neutrinos. In such an environment, proton-rich nuclides can be produced in sequences of proton captures and (n, p) rea... Read More about Uncertainties in νp-process nucleosynthesis from Monte Carlo variation of reaction rates.

Grids of stellar models with rotation IV. Models from 1.7 to 120 M-circle dot at a metallicity Z=0.0004 (2019)
Journal Article
Groh, J., Ekström, S., Georgy, C., Meynet, G., Choplin, A., Eggenberger, P., …Farrell, E. (2019). Grids of stellar models with rotation IV. Models from 1.7 to 120 M-circle dot at a metallicity Z=0.0004. Astronomy & Astrophysics, 627, Article A24. https://doi.org/10.1051/0004-6361/201833720

The effects of rotation on stellar evolution are particularly important at low metallicity, when mass loss by stellar winds diminishes and the surface enrichment due to rotational mixing becomes relatively more pronounced than at high metallicities.... Read More about Grids of stellar models with rotation IV. Models from 1.7 to 120 M-circle dot at a metallicity Z=0.0004.

Constraining transport of angular momentum in stars Combining asteroseismic observations of core helium burning stars and white dwarfs (2019)
Journal Article
den Hartogh, J., Eggenberger, P., & Hirschi, R. (2019). Constraining transport of angular momentum in stars Combining asteroseismic observations of core helium burning stars and white dwarfs. Astronomy & Astrophysics, 622, 1-10. https://doi.org/10.1051/0004-6361/201834330

Context Transport of angular momentum has been a challenging topic within the stellar evolution community, even more since the recent asteroseismic surveys. All published studies on rotation using asteroseismic observations show a discrepancy betwee... Read More about Constraining transport of angular momentum in stars Combining asteroseismic observations of core helium burning stars and white dwarfs.

Dependence of convective boundary mixing on boundary properties and turbulence strength (2019)
Journal Article
Cristini, A., Hirschi, R., Meakin, C., Arnett, D., Georgy, C., & Walkington, I. (2019). Dependence of convective boundary mixing on boundary properties and turbulence strength. Monthly Notices of the Royal Astronomical Society, 484(4), 4645 - 4664. https://doi.org/10.1093/mnras/stz312

Convective boundary mixing is one of the major uncertainties in stellar evolution. In order to study its dependence on boundary properties and turbulence strength in a controlled way, we computed a series of 3D hydrodynamical simulations of stellar c... Read More about Dependence of convective boundary mixing on boundary properties and turbulence strength.

Non-standard s-process in massive rotating stars (2018)
Journal Article
Hirschi, R. (2018). Non-standard s-process in massive rotating stars. Astronomy and Astrophysics, https://doi.org/10.1051/0004-6361/201833283

Context Recent studies show that rotation significantly affects the s-process in massive stars. Aims We provide tables of yields for non-rotating and rotating massive stars between 10 and 150 M? at Z = 10-3 ([Fe/H] = -1.8). Tables for different... Read More about Non-standard s-process in massive rotating stars.