Computational Models of X-Ray Burst Quenching Times and 12C Nucleosynthesis Following a Superburst

Fisker, J L

关键词: DECAY;    IGNITION;    NEUTRON STARS;    NUCLEOSYNTHESIS;    PHYSICS;    QUENCHING;    THERMONUCLEAR EXPLOSIONS;   

DOI  :  10.2172/989344
RP-ID  :  LLNL-TR-412521
PID  :  OSTI ID: 989344
Others  :  TRN: US1007095

美国|英语

来源: SciTech Connect

【 摘 要 】

Superbursts are energetic events on neutron stars that are a thousand times more powerful than ordinary type I X-ray bursts. They are believed to be powered by a thermonuclear explosion of accumulated {sup 12}C. However, the source of this {sup 12}C remains elusive to theoretical calculations and its concentration and ignition depth are both unknown. Here we present the first computational simulations of the nucleosynthesis during the thermal decay of a superbust, where X-ray bursts are quenched. Our calculations of the quenching time verify previous analytical calculations and shed new light on the physics of stable burning at low accretion rates. We show that concentrated (X{sub {sup 12}C} {approx}> 0.40), although insufficient, amounts of {sup 12}C are generated during the several weeks following the superburst where the decaying thermal flux of the superburst stabilizes the burning of the accreted material.