moon_sleep150.gif
Cococubed.com


an r-process

Home

Astronomy research
  Software Infrastructure:
     MESA
     FLASH-X
     STARLIB
     MESA-Web
     starkiller-astro
     My instruments
  White dwarf supernova:
     Stable nickel production
     Remnant metallicities
     Colliding white dwarfs
     Merging white dwarfs
     Ignition conditions
     Metallicity effects
     Central density effects
     Detonation density effects
     Tracer particle burning
     Subsonic burning fronts
     Supersonic burning fronts
     W7 profiles
  Massive star supernova:
     Rotating progenitors
     3D evolution
     26Al & 60Fe
     44Ti, 60Co & 56Ni
     Yields of radionuclides
     Effects of 12C +12C
     SN 1987A light curve
     Constraints on Ni/Fe ratios
     An r-process
  Neutron Stars and Black Holes:
     Black Hole mass spectrum
     Compact object IMF
     He burn on neutron stars
  Stars:
     Variable white dwarfs
     Pop III with JWST
     Micronovae
     Neutrino HR diagram
     Monte Carlo massive stars
     Pre-supernova neutrinos
     Pre-supernova variations
     Monte Carlo white dwarfs
     SAGB stars
     Nugrid Yields I
     Classical novae
     He shell convection
     Presolar grains
     BBFH at 40 years
  Chemical Evolution:
     Iron Pseudocarbynes
     Radionuclides in the 2020s
     Hypatia catalog
     Zone models H to Zn
     Mixing ejecta
     γ-rays within 100 Mpc
  Thermodynamics & Networks
     Stellar EOS
     12C(α,γ)16O Rate
     Proton-rich NSE
     Reaction networks
     Bayesian reaction rates
  Verification Problems:
     Validating an astro code
     Su-Olson
     Cog8
     Mader
     RMTV
     Sedov
     Noh
Software instruments
Presentations
Illustrations
cococubed YouTube
Bicycle adventures
Public Outreach
Education materials
2022 ASU Solar Systems Astronomy
2022 ASU Energy in Everyday Life

AAS Journals
AAS YouTube
2022 Earendel, A Highly Magnified Star
2022 TV Columbae, Micronova
2022 White Dwarfs and 12C(α,γ)16O
2022 MESA VI
2022 MESA in Don't Look Up
2022 MESA Marketplace
2022 MESA Summer School
2022 MESA Classroom
2021 Bill Paxton, Tinsley Prize


Contact: F.X.Timmes
my one page vitae,
full vitae,
research statement, and
teaching statement.
Supernova fallback: a possible site for the r-process (2006)

In this article we investigate the mass ejected by fallback in a supernova explosion. Trans-iron element production beyond the second peak is made possible by a rapid (< 1 ms) freezeout of α-particles that leaves behind a large nucleon (including protons!) to r-process seed ratio. This rapid phase is followed by a relatively long (≤ 15 ms) simmering phase at < 2x109 K, which is a consequence of the hydrodynamic trajectory of the turbulent flows in the fallback outburst. During the slow phase, heavy elements beyond the second peak are first made through rapid capture of both protons and neutrons. The flow stays close to the valley of stability during this phase. After freezeout of protons the remaining neutrons cause a shift to short-lived isotopes, as is typical for the r-process. A low electron fraction is not required in this model; however, the detailed final distribution is sensitive to the electron fraction. Our simulations suggest that supernova fallback is a viable alternative scenario for the r-process.

Brad Meyer's article, is highly relevant in this scenario.


image
ejecta after fallback
image
abundance pattern of ejecta
image
n, p, α evolution
image
image image
image
meyer ratio (unpublished)