English
Related papers

Related papers: r-Process Calculations and Galactic Chemical Evolu…

200 papers

We calculate Galactic Chemical Evolution (GCE) of Mo and Ru by taking into account the contribution from $\nu p$-process nucleosynthesis. We estimate yields of $p$-nuclei such as $^{92,94}\mathrm{Mo}$ and $^{96,98}\mathrm{Ru}$ through the…

At present none of Galactic chemical evolution (GCE) models provides a self-consistent description of observed trends for all iron-peak elements with metallicity simultaneously. The question is whether the discrepancy is due to deficiencies…

Solar and Stellar Astrophysics · Physics 2015-05-14 Maria Bergemann , Thomas Gehren

The very-metal-poor halo star CS31082-001 was discovered to be very strongly r-process-enhanced during the course of a VLT+UVES high-resolution follow-up of metal-poor stars identified in the HK survey of Beers and colleagues. Both the…

Astrophysics · Physics 2007-05-23 V. Hill , B. Plez , R. Cayrel , T. C. Beers

Knowledge of abundance ratios as functions of metallicity can lead to insights on the origin and evolution of our Galaxy and its stellar populations. We aim to trace the chemical evolution of the neutron-capture elements Sr, Zr, La, Ce, Nd,…

Solar and Stellar Astrophysics · Physics 2017-04-26 Chiara Battistini , Thomas Bensby

The chemical abundances of metal-poor stars are an excellent test bed by which to set new constraints on models of neutron-capture processes at low metallicity. Some r-process-rich (hereafter r-rich) metal-poor stars, such as HD221170, show…

Solar and Stellar Astrophysics · Physics 2010-10-25 Jiang Zhang , Wenyuan Cui , Bo Zhang

We investigate $r$-process nucleosynthesis in three-dimensional general relativistic magnetohydrodynamic simulations of jet-driven supernovae resulting from rapidly rotating, strongly magnetized core-collapse. We explore the effect of…

High Energy Astrophysical Phenomena · Physics 2018-04-11 Goni Halevi , Philipp Mösta

The identification of the astrophysical site and the specific conditions in which r-process nucleosynthesis takes place remain unsolved mysteries of astrophysics. The present paper emphasizes some important future challenges faced by…

Astrophysics · Physics 2009-11-10 S. Goriely , P. Demetriou , H. -Th. Janka , J. M. Pearson , M. Samyn

Diffuse neutrino fluxes attributed to two different physical processes in core collapse of massive stars are visited with their potentiality of exploring stellar physics more deeply being stressed. In this work, available models of thermal…

High Energy Astrophysical Phenomena · Physics 2026-02-24 Yosuke Ashida

A few topics concerning the early chemical evolution of the Milky Way are critically discussed. In particular, it is argued that: 1) Observed abundance patterns of extremely metal poor stars (of Pop. II) do not constrain the mass range of…

Astrophysics · Physics 2007-05-23 Nikos Prantzos

About half of the heavy elements beyond iron are known to be produced by the rapid neutron capture process, known as r-process. However, the astrophysical site producing the r-process is still uncertain. Chemical abundances observed in…

Motivated by the recently improved knowledge on the kinematic and chemical properties of the Galactic metal-poor stars, we present the numerical simulation for the formation of the Galactic stellar halo to interpret the observational…

Astrophysics · Physics 2009-10-31 Kenji Bekki , Masashi Chiba

It is unclear if neutron star mergers can explain the observed r-process abundances of metal-poor stars. Collapsars, defined here as rotating massive stars whose collapse results in a rapidly accreting disk around a black hole that can…

High Energy Astrophysical Phenomena · Physics 2021-07-21 Kaley Brauer , Alexander P. Ji , Maria R. Drout , Anna Frebel

The chemical abundances of metal-poor stars provide important clues to explore stellar formation history and set significant constraints on models of the r-process. In this work, we find that the abundance patterns of the light and iron…

Solar and Stellar Astrophysics · Physics 2014-07-21 Hongjie Li , Wenjuan Ma , Wenyuan Cui , Bo Zhang

We perform numerical simulations for the formation of the Galactic stellar halo, based on the currently favored cold dark matter (CDM) theory of galaxy formation. Our numerical models, taking into account both dynamical and chemical…

Astrophysics · Physics 2009-11-06 Kenji Bekki , Masashi Chiba

The production of the heavy stable proton-rich isotopes between 74Se and 196Hg -- the p nuclides -- is due to the contribution from different nucleosynthesis processes, activated in different types of stars. Whereas these processes have…

Solar and Stellar Astrophysics · Physics 2018-02-09 C. Travaglio , T. Rauscher , A. Heger , M. Pignatari , C. West

In star forming regions, we can observe different evolutionary stages of various objects and phenomena such as molecular clouds, protostellar jets and outflows, circumstellar disks, and protostars. However, it is difficult to directly…

Solar and Stellar Astrophysics · Physics 2015-05-19 Masahiro N. Machida

The theory of how low mass stars form from the collapse of a dense molecular cloud core has been well-established for decades. Thanks to significant progress in computing and numerical modelling, more physical models have been developed and…

Solar and Stellar Astrophysics · Physics 2024-01-05 Alison K. Young

The detailed chemical composition of most metal-poor halo stars has been found to be highly uniform, but a minority of stars exhibit dramatic enhancements in their abundances of heavy neutron-capture elements and/or of carbon. The key…

Solar and Stellar Astrophysics · Physics 2015-11-04 T. T. Hansen , J. Andersen , B. Nordstrøm , T. C. Beers , J. Yoon , L. A. Buchhave

The nucleosynthetic site of the rapid ($r$) neutron-capture process is currently being debated. The direct detection of the neutron star merger GW170817, through gravitational waves and electromagnetic radiation, has confirmed such events…

Astrophysics of Galaxies · Physics 2020-02-05 Ása Skúladóttir , Stefania Salvadori

Neutron star mergers have been long considered as promising sites of heavy $r$-process nucleosynthesis. We overview observational evidence supporting this scenario including: the total amount of $r$-process elements in the Galaxy, extreme…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Kenta Hotokezaka , Paz Beniamini , Tsvi Piran