A. Parikh

The effects of variations in nuclear processes on type I X-ray burst nucleosynthesis

Type I X-ray bursts are violent stellar events that take place in the H/He-rich envelopes of accreting neutron stars. We have investigated the role played by uncertainties in nuclear processes on the nucleosynthesis accompanying these explosive phenomena. Two different approaches have been adopted, in the framework of postprocessing calculations. In the first one, nuclear rates are varied individually within uncertainties. Ten different models, covering the characteristic parameter space for these stellar events, have been considered. The second, somewhat complementary approach involves a Monte Carlo code in which all nuclear rates are randomly varied within uncertainty limits simultaneously. All in all, about 50,000 postprocessing calculations, with a network containing 606 nuclides (H to 113Xe) and more than 3500 nuclear processes, have been performed in this work. A brief comparison between both procedures is outlined together with an overall account of the key nuclear reactions whose uncertainties have the largest impact in our X-ray burst nucleosynthesis studies.

Nucleosynthesis in Type I X-ray Bursts

Abstract Type I X-ray bursts are thermonuclear explosions that occur in the envelopes of accreting neutron stars. Detailed observations of these phenomena have prompted numerous studies in theoretical astrophysics and experimental nuclear physics since their discovery over 35 years ago. In this review, we begin by discussing key observational features of these phenomena that may be sensitive to the particular patterns of nucleosynthesis from the associated thermonuclear burning. We then summarize efforts to model type I X-ray bursts, with emphasis on determining the nuclear physics processes involved throughout these bursts. We discuss and evaluate limitations in the models, particularly with regard to key uncertainties in the nuclear physics input. Finally, we examine recent, relevant experimental measurements and outline future prospects to improve our understanding of these unique environments from observational, theoretical and experimental perspectives.

Impact of uncertainties in reaction Q values on nucleosynthesis in type I x-ray bursts

Nucleosynthesis in type I X-ray bursts may involve up to several thousand nuclear processes. The majority of these processes have only been determined theoretically due to the lack of sufficient experimental information. Accurate reaction

Hydrodynamic Models of Type I X-ray Bursts: Metallicity Effects

Q

Classical novae and type I X-ray bursts: Challenges for the 21st century

-values are essential for reliable theoretical estimates of reaction rates. Those reactions with small

The effects of variations in nuclear interactions on nucleosynthesis in thermonuclear supernovae

Q

Constraints on the mass and radius of the accreting neutron star in the rapid burster

-values (

Non-extensive Statistics to the Cosmological Lithium Problem

l1

Constraining nova observables: direct measurements of resonance strengths in 33S(p,\gamma)34Cl

MeV) are of particular interest in these environments as they may represent waiting points for a continuous abundance flow toward heavier-mass nuclei. To explore the nature of these waiting points, we have performed a comprehensive series of post-processing calculations which examine the sensitivity of nucleosynthesis in type I X-ray bursts to uncertainties in reaction

Investigation of the thermonuclear 18 Ne(α, p) 21 Na reaction rate via resonant elastic scattering of 21 Na + p

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