All Outputs (8)

Massive Stars as Cosmic Engines through the Ages (2008)
Journal Article
Hirschi, R. (2008). Massive Stars as Cosmic Engines through the Ages. Proceedings of the International Astronomical Union, 3-16. https://doi.org/10.1017/S1743921308020292

Some useful developments in the model physics are briefly presented, followed by model results on chemical enrichments and WR stars. We discuss the expected rotation velocities of WR stars. We emphasize that the (C+O)/He ratio is a better chemical in... Read More about Massive Stars as Cosmic Engines through the Ages.

NuGrid: s process in massive stars (2008)
Journal Article
Frischknecht, U., Thielemann, F., -K. Thielemann, F., Pignatari, M., Bennett, M., Diehl, S., …Hirschi, R. NuGrid: s process in massive stars. Manuscript submitted for publication

The s-process production in massive stars at very low metallicities is expected to be negligible due to the low abundance of the neutron source 22Ne, to primary neutron poisons and decreasing iron seed abundances. However, recent models of massive st... Read More about NuGrid: s process in massive stars.

Nucleosynthesis simulations for a wide range of nuclear production sites from NuGrid (2008)
Journal Article
Herwig, F., Fryer, C., Hirschi, R., Bennett, M., L. Fryer, C., Diehl, S., …Young, P. Nucleosynthesis simulations for a wide range of nuclear production sites from NuGrid. Manuscript submitted for publication

Simulations of nucleosynthesis in astrophysical environments are at the intersection of nuclear physics reaction rate research and astrophysical applications, for example in the area of galactic chemical evolution or near-field cosmology. Unfortunate... Read More about Nucleosynthesis simulations for a wide range of nuclear production sites from NuGrid.

The impact of reduced mass loss rates on the evolution of massive stars (2008)
Conference Proceeding
Hirschi, R. (2008). The impact of reduced mass loss rates on the evolution of massive stars.

Mass loss is a very important aspect of the life of massive stars. After briefly reviewing its importance, we discuss the impact of the recently proposed downward revision of mass loss rates due to clumping (difficulty to form Wolf-Rayet stars and pr... Read More about The impact of reduced mass loss rates on the evolution of massive stars.

The s process in massive stars at low metallicity. Effect of primary N14 from fast rotating stars (2008)
Journal Article
Pignatari, M., Gallino, R., Meynet, G., Hirschi, R., Herwig, F., & Wiescher, M. (2008). The s process in massive stars at low metallicity. Effect of primary N14 from fast rotating stars. Astrophysical Journal, https://doi.org/10.1086/593350

The goal of this paper is to analyze the impact of a primary neutron source on the s-process nucleosynthesis in massive stars at halo metallicity. Recent stellar models including rotation at very low metallicity predict a strong production of primary... Read More about The s process in massive stars at low metallicity. Effect of primary N14 from fast rotating stars.

Difficulties in Probing Nuclear Physics: A Study of Ti and Ni (2008)
Presentation / Conference
Hungerford, A., Fryer, C. L., Timmes, F. X., Young, P., Bennett, M., Diehl, S., …Rockefeller, G. (2008, July). Difficulties in Probing Nuclear Physics: A Study of Ti and Ni. Paper presented at 10th Symposium on Nuclei in the Cosmos, Mackinac Island, Michigan, USA

The nucleosynthetic yield from a supernova explosion depends upon a variety of effects: progenitor evolution, explosion process, details of the nuclear network, and nuclear rates. Especially in studies of integrated stellar yields, simplifications re... Read More about Difficulties in Probing Nuclear Physics: A Study of Ti and Ni.

44Ti and 56Ni in core-collapse supernovae (2008)
Presentation / Conference
Magkotsios, G., Timmes, F. X., Wiescher, M., Fryer, C. L., Hungerford, A., Young, P., …Rockefeller, G. (2008, July). 44Ti and 56Ni in core-collapse supernovae. Paper presented at 10th Symposium on Nuclei in the Cosmos, Mackinac Island, Michigan, USA

We investigate the physical conditions where 44Ti and 56Ni are created in core-collapse supernovae. In this preliminary work we use a series of post-processing network calculations with parametrized expansion profiles that are representative of the w... Read More about 44Ti and 56Ni in core-collapse supernovae.

Stellar Evolution in the Early Universe (2008)
Journal Article
Hirschi, R., Frischknecht, U., -K. Thielemann, F., Pignatari, M., Chiappini, C., Ekstroem, S., …Maeder, A. (2008). Stellar Evolution in the Early Universe. Proceedings of the International Astronomical Union, 4(S255), https://doi.org/10.1017/S1743921308024976

Massive stars played a key role in the early evolution of the Universe. They formed with the first halos and started the re-ionisation. It is therefore very important to understand their evolution. In this paper, we describe the strong impact of rota... Read More about Stellar Evolution in the Early Universe.