{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/a-bayesian-approach-to-matching-thermonuclear","title":"A Bayesian Approach to Matching Thermonuclear X-ray Burst Observations with Models","arxiv_id":"1907.00996","date":"2019-07-01","proceeding":null,"authors":["A. J. Goodwin","D. K. Galloway","A. Heger","A. Cumming","Z. Johnston"],"abstract":"We present a new method of matching observations of Type I (thermonuclear) X-ray bursts with models, comparing the predictions of a semi-analytic ignition model with X-ray observations of the accretion-powered millisecond pulsar SAX J1808.4--3658 in outburst. We used a Bayesian analysis approach to marginalise over the parameters of interest and determine parameters such as fuel composition, distance/anisotropy factors, neutron star mass and neutron star radius. Our study includes a treatment of the system inclination effects, inferring that the rotation axis of the system is inclined $\\left(69^{+4}_{-2}\\right)^\\circ$ from the observers line of sight, assuming a flat disc model. This method can be applied to any accreting source that exhibits Type I X-ray bursts. We find a hydrogen mass fraction of $0.57^{+0.13}_{-0.14}$ and CNO metallicity of $0.013^{+0.006}_{-0.004}$ for the accreted fuel is required by the model to match the observed burst energies, for a distance to the source of $3.3^{+0.3}_{-0.2}\\,\\mathrm{kpc}$. We infer a neutron star mass of $1.5^{+0.6}_{-0.3}\\,\\mathrm{M}_{\\odot}$ and radius of $11.8^{+1.3}_{-0.9}\\,\\mathrm{km}$ for a surface gravity of $1.9^{+0.7}_{-0.4}\\times10^{14}\\,\\mathrm{cm}\\,\\mathrm{s}^{-2}$ for SAX J1808.4--3658.","url_abs":"https://arxiv.org/abs/1907.00996v2","url_pdf":"https://arxiv.org/pdf/1907.00996v2.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"a-bayesian-approach-to-matching-thermonuclear","repo_url":"https://github.com/adellej/beans","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}