skip to main content


This content will become publicly available on June 21, 2019

Title: Consistent Modeling of GS 1826-24 X-Ray Bursts for Multiple Accretion Rates Demonstrates the Possibility of Constraining rp-process Reaction Rates

Type-I X-ray burst light curves encode unique information about the structure of accreting neutron stars and the nuclear reaction rates of the rp-process that powers bursts. Using the first model calculations of hydrogen/helium-burning bursts for a large range of astrophysical conditions performed with the code MESA, this work shows that simultaneous model–observation comparisons for bursts from several accretion rates $$\dot{M}$$ are required to remove degeneracies in astrophysical conditions that otherwise reproduce bursts for a single $$\dot{M}$$ and that such consistent multi-epoch modeling could possibly limit the 15O(α, γ) 19Ne reaction rate. Comparisons to the 1998, 2000, and 2007 bursting epochs of the neutron star GS 1826-24 show that $$\dot{M}$$ must be larger than previously inferred and that the shallow heating in this source must be below 0.5 MeV/u, providing a new method to constrain the shallow heating mechanism in the outer layers of accreting neutron stars. Lastly, features of the light curve rise are used to demonstrate that a lower limit could likely be placed on the 15O(α, γ) reaction rate, demonstrating the possibility of constraining nuclear reaction rates with X-ray burst light curves.
  1. Ohio Univ., Athens, OH (United States). Inst. of Nuclear & Particle Physics, Dept. of Physics & Astronomy
Publication Date:
Grant/Contract Number:
FG02-88ER40387; PHY-1430152
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 860; Journal Issue: 2; Journal ID: ISSN 1538-4357
Institute of Physics (IOP)
Research Org:
Ohio Univ., Athens, OH (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26); National Science Foundation (NSF)
Contributing Orgs:
Joint Institute for Nuclear Astrophysics
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; nuclear reactions; nucleosynthesis; abundances – stars: neutron – X-rays: bursts
OSTI Identifier: