Browsing by Author "Hirschi, R."

Now showing items 1-17 of 17

    • Abundance uncertainties obtained with the PIZBUIN framework for Monte Carlo reaction rate variations 

      Rauscher, T.; Nishimura, N.; Cescutti, G.; Hirschi, R.; Murphy, A. St J. (American Institute of Physics (AIP), 2018-04-25)
      Uncertainties in nucleosynthesis models originating from uncertainties in astrophysical reaction rates were estimated in a Monte Carlo variation procedure. Thousands of rates were simultaneously varied within individual, ...

    • Boron depletion in 9 to 15 M(circle dot) stars with rotation 

      Frischknecht, U.; Hirschi, R.; Meynet, G.; Ekstroem, S.; Georgy, C.; Rauscher, T.; Winteler, C.; Thielemann, F-K. (Cambridge University Press, 2010)
      The treatment of mixing is still one of the major uncertainties in stellar evolution models. One open question is how well the prescriptions for rotational mixing describe the real effects. We tested the mixing prescriptions ...

    • Constraints on rotational mixing from surface evolution of light elements in massive stars 

      Frischknecht, U.; Hirschi, R.; Meynet, G.; Ekstroem, S.; Georgy, C.; Rauscher, T.; Winteler, C.; Thielemann, Friedrich-Karl (2010-11)
      Context. Light elements and nitrogen surface abundances together can constrain the mixing efficiencies in massive stars on the main sequence, because moderate mixing in the surface layers leads to depletion of light elements ...

    • Impact of rotation on the weak s-process 

      Frischknecht, U.; Hirschi, R.; Rauscher, T.; Thielemann, Friedrich-Karl (SISSA, 2011-01)
      The weak s process takes place in massive stars and it produces the majority of s-only isotopes in the atomic mass range from 60 to 90. This process is qualitatively well understood. However, there are still large uncertainties ...

    • Impacts of nuclear-physics uncertainty in stellar temperatures on the s-process nucleosynthesis 

      Nishimura, N.; Cescutti, G.; Hirschi, R.; Rauscher, T.; Hartogh, J. Den; Murphy, A. St J. (The Physical Society of Japan, 2017-02-28)
      We evaluated the uncertainty relevant to s-process nucleosynthesis using a Monte-Carlo centred approach. We are based on a realistic and general prescription of temperature dependent uncertainty for the reactions. We ...

    • Nuclear physics : A key ingredient in astrophysical modeling 

      Thielemann, Friedrich-Karl; Argast, D.; Brachwitz, F.; Fisker, J. L.; Froehlich, Carla; Hirschi, R.; Kolbe, E.; Mocelj, D.; Rauscher, T. (2005-04-18)
      Nuclear physics is a basic ingredient in a large number of energetic astrophysical environments which are characterized by sufficient temperatures and densities to permit scattering events among particles, leading to nuclear ...

    • The Nuclear Reaction Network WinNet 

      Reichert, M.; Winteler, C.; Korobkin, O.; Arcones, A.; Bliss, J.; Eichler, M.; Frischknecht, U.; Fröhlich, C.; Hirschi, R.; Jacobi, M.; Kuske, J.; Martínez-Pinedo, G.; Martin, D.; Mocelj, D.; Rauscher, T.; Thielemann, F.-K. (2023-10-11)
      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 ...

    • Production of intermediate-mass and heavy nuclei 

      Thielemann, Friedrich-Karl; Froehlich, Carla; Hirschi, R.; Liebendoerfer, M.; Dillmann, I.; Mocelj, D.; Rauscher, T.; Martinez-Pinedo, G.; Langanke, K.; Farouqi, K.; Kratz, K.L.; Pfeiffer, B.; Panov, I.; Nadyozhin, D. K.; Blinnikov, S.; Bravo, E.; Hix, W. R.; Hoflich, P.; Zinner, N. T. (Elsevier, 2007)
      Nucleosynthesis is the science related to all astrophysical processes which are responsible for the abundances of the elements and their isotopes in the universe. The astrophysical sites are the big bang and stellar objects. ...

    • Production Uncertainties of p-Nuclei in the γ-Process in Massive Stars Using a Monte Carlo Approach 

      Rauscher, T.; Nishimura, N.; Hirschi, R.; Cescutti, G.; Murphy, A. St J.; Heger, A. (2017-02-28)
      Proton-rich nuclei, the so-called p-nuclei, are made in photodisintegration processes in outer shells of massive stars in the course of the final supernova explosion. Nuclear uncertainties in the production of these nuclei ...

    • The s-process nucleosynthesis : Impact of the uncertainties in the nuclear physics determined by monte carlo variations 

      Cescutti, G.; Nishimura, N.; Hirschi, R.; Rauscher, T.; den Hartogh, J. W.; Murphy, A. St J. (2017-10-01)
      We investigated the impact of uncertainties in neutron-capture and weak reactions (on heavy elements) on the s-process nucleosynthesis in low-mass stars and massive stars using a Monte-Carlo based approach. We performed ...

    • Sensitivity to neutron captures and β-decays of the enhanced s-process in rotating massive stars at low metallicities 

      Nishimura, N.; Hirschi, R.; Rauscher, T. (2018-01-31)
      The s-process in massive stars, producing nuclei up to A ≈ 90, has a different behaviour at low metallicity if stellar rotation is significant. This enhanced s-process is distinct from the s-process in massive stars around ...

    • Silicon carbide grains of type C provide evidence for the production of the unstable isotope Si in supernovae 

      Pignatari, M.; Zinner, E.; Bertolli, M.G.; Trappitsch, R.; Hoppe, P.; Rauscher, T.; Fryer, C.; Herwig, F.; Hirschi, R.; Timmes, F.X.; Thielemann, F.-K. (2013-07-01)
      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 ...

    • Theory considerations for nucleosynthesis beyond Fe with special emphasis on p-nuclei in massive stars 

      Rauscher, T.; Nishimura, N.; Hirschi, R. (American Institute of Physics (AIP), 2016-06-21)
      Nucleosynthesis of heavy elements requires the use of different experimental and theoretical methods to determine astrophysical reaction rates than light element nucleosynthesis. Additionally, there are also larger ...

    • Uncertainties in s-process nucleosynthesis in low-mass stars determined from Monte Carlo variations 

      Cescutti, G.; Hirschi, R.; Nishimura, N.; den Hartogh, J. W.; Rauscher, T.; Murphy, A. St J.; Cristallo, S. (2018-08-21)
      The main s-process taking place in low-mass stars produces about half of the elements heavier than iron. It is therefore very important to determine the importance and impact of nuclear physics uncertainties on this process. ...

    • Uncertainties in the production of p nuclei in massive stars obtained from Monte Carlo variations 

      Rauscher, T.; Nishimura, N.; Hirschi, R.; Cescutti, G.; Murphy, A. St J.; Heger, A. (2016-12-21)
      Nuclear uncertainties in the production of $p$ nuclei in massive stars have been quantified in a Monte Carlo procedure. Bespoke temperature-dependent uncertainties were assigned to different types of reactions involving ...

    • Uncertainties in the production of p nuclides in thermonuclear supernovae determined by Monte Carlo variations 

      Nishimura, N.; Rauscher, T.; Hirschi, R.; Murphy, A. St J.; Cescutti, G.; Travaglio, C. (2018-03-01)
      Thermonuclear supernovae originating from the explosion of a white dwarf accreting mass from a companion star have been suggested as a site for the production of p nuclides. Such nuclei are produced during the explosion, ...

    • Uncertainties in νp-process nucleosynthesis from Monte Carlo variation of reaction rates 

      Nishimura, N.; Rauscher, T.; Hirschi, R.; Cescutti, G.; Murphy, A. St J.; Fröhlich, C. (2019-10)
      It has been suggested that a νp-process can occur when hot, dense, and proton-rich matter is expanding within a strong flux of antineutrinos. In such an environment, proton-rich nuclides can be produced in sequences of ...