Nucleosynthesis in neutron-rich ejecta from Quark-Novae.

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Astron. Astrophys.

DOI:https://doi.org/10.1051/0004-6361:20066593· OSTI ID:941484

Jaikumar, P; Ouyed, R; Otsuki, K; Meyer, B S

We explore heavy-element nucleosynthesis by rapid neutron capture (r-process) in the decompressing ejecta from the surface of a neutron star. The decompression is triggered by a violent phase transition to strange quark matter (quark-nova scenario). The presence of neutron-rich large Z nuclei (40,95) < (Z,A) < (70,177), the large neutron-to-seed ratio, and the low electron fraction Y{sub e} {approx} 0.03 in the decompressing ejecta present favorable conditions for the r-process. We perform network calculations that are adapted to the quark-nova conditions, and which mimic usual (n-{gamma}) equilibrium r-process calculations during the initially cold decompression phase. They match to dynamical r-process calculations at densities below neutron drip (4 x 10{sup 11} g cm{sup -3}). We present results for the final element abundance distribution with and without heating from nuclear reactions, and compare to the solar abundance pattern of r-process elements. We highlight the distinguishing features of quark-novae by contrasting it with conventional nucleosynthetic sites such as type II supernovae and neutron star mergers, especially in the context of heavy-element compositions of extremely metal-deficient stars.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; FOR; NSF; NASA
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 941484
• Report Number(s): ANL/PHY/JA-57384
• Journal Information: Astron. Astrophys., Journal Name: Astron. Astrophys. Journal Issue: 2007 Vol. 471; ISSN AAEJAF; ISSN 0004-6361
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABUNDANCE
CAPTURE
ELECTRONS
ELEMENT ABUNDANCE
HEATING
NEUTRON REACTIONS
NEUTRON STARS
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
NUCLEOSYNTHESIS
QUARK MATTER
R PROCESS
STARS
SUPERNOVAE