Where, oh where has the r-process gone?

Details Where, oh where has the r-process gone? Where, oh where has the r-process gone?

2007-08-13

arxiv.org/abs/0708.1767v1

Phys.Rept.442:237-268,2007

Astronomy and Astrophysics

Astrophysics

52 pages including figures

Scientific paper

10.1016/j.physrep.2007.02.006

We present a review of the possible sources for r-process nuclei. It is known that there is as yet no self-consistent mechanism to provide abundant neutrons for a robust r-process in the neutrino-driven winds from nascent neutron stars. We consider that the heavy r-nuclei with mass numbers A>130 (Ba and above) cannot be produced in the neutrino-driven winds. Nonetheless, the r-process and the neutrino-driven winds may be directly or indirectly related by some unknown additional mechanism, which, for example, could provide ejecta with very short dynamic timescales of <0.004 s. This undetermined mechanism must supply a neutron source within the same general stellar sites that undergo core collapse to produce the neutron star. Observational data on low-metallicity stars in the Galactic halo show that sites producing the heavy r-nuclei do not produce Fe or any other elements between N and Ge. Insofar as a forming neutron star is key to producing the heavy r-nuclei, then the only possible sources are supernovae resulting from collapse of O-Ne-Mg cores or accretion-induced collapse of white dwarfs, neither of which produce the elements of the Fe group or those of intermediate mass (above C and N). Using a template star with high enrichments of heavy r-nuclei and another with low enrichments we develop a two-component model based on the abundances of Eu (from sources for heavy r-nuclei) and Fe (from Fe core-collapse supernovae). This model gives very good quantitative predictions for the abundances of all the other elements in those metal-poor stars with [Fe/H]<-1.5 for which the Eu and Fe abundances are known. (Abridged)

Affiliated with

Also associated with

No associations

Rating

Where, oh where has the r-process gone? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Where, oh where has the r-process gone?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Where, oh where has the r-process gone? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-388418