{"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/determination-of-the-turbulent-parameter-in","title":"Determination of the turbulent parameter in the accretion disks: effects of self-irradiation in 4U 1543-47 during the 2002 outburst","arxiv_id":"1610.01399","date":"2016-10-05","proceeding":null,"authors":["G. V. Lipunova","K. L. Malanchev"],"abstract":"We investigate the viscous evolution of the accretion disk in 4U 1543-47, a black hole binary system, during the first 30 days after the peak of the 2002 burst by comparing the observed and theoretical accretion rate evolution $\\dot M(t)$. The observed $\\dot M(t)$ is obtained from spectral modelling of the archival RXTE/PCA data. Different scenarios of disk decay evolution are possible depending on a degree of self-irradiation of the disk by the emission from its centre. If the self-irradiation, which is parametrized by factor $C_\\mathrm{irr}$, had been as high as $\\sim 5\\times10^{-3}$, then the disk would have been completely ionized up to the tidal radius and the short time of the decay would have required the turbulent parameter $\\alpha\\sim 3$. We find that the shape of the $\\dot M(t)$ curve is much better explained in a model with a shrinking high-viscosity zone. If $C_\\mathrm{irr}\\approx(2-3)\\times 10^{-4}$, the resulting $\\alpha$ lie in the interval $0.5-1.5$ for the black hole masses in the range $6-10~\\mathrm{M}_\\odot$, while the radius of the ionized disk is variable and controlled by irradiation. For very weak irradiation, $C_\\mathrm{irr} < 1.5 \\times10^{-4}$, the burst decline develops as in normal outbursts of dwarf novae with $\\alpha \\sim 0.08-0.32$. The optical data indicate that $C_\\mathrm{irr}$ in 4U 1543-47 (2002) was not greater than approximately $(3-6)\\times10^{-4}$. Generally, modelling of an X-ray nova burst allows one to estimate $\\alpha$ that depends on the black hole parameters. We present the public 1-D code Freddi to model the viscous evolution of an accretion disk. Analytic approximations are derived to estimate $\\alpha$ in X-ray novae using $\\dot M(t)$.","url_abs":"https://arxiv.org/abs/1610.01399v3","url_pdf":"https://arxiv.org/pdf/1610.01399v3.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":"determination-of-the-turbulent-parameter-in","repo_url":"https://github.com/hombit/freddi","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}