Skip to content Skip to navigation
University of Warwick
  • Study
  • |
  • Research
  • |
  • Business
  • |
  • Alumni
  • |
  • News
  • |
  • About

University of Warwick
Publications service & WRAP

Highlight your research

  • WRAP
    • Home
    • Search WRAP
    • Browse by Warwick Author
    • Browse WRAP by Year
    • Browse WRAP by Subject
    • Browse WRAP by Department
    • Browse WRAP by Funder
    • Browse Theses by Department
  • Publications Service
    • Home
    • Search Publications Service
    • Browse by Warwick Author
    • Browse Publications service by Year
    • Browse Publications service by Subject
    • Browse Publications service by Department
    • Browse Publications service by Funder
  • Help & Advice
University of Warwick

The Library

  • Login
  • Admin

On the production and survival of carbon fuel for superbursts on accreting neutron stars : implications for mass donor evolution

Tools
- Tools
+ Tools

Cooper, Randall L., Mukhopadhyay, Banibrata, Steeghs, D. and Narayan, Ramesh (2006) On the production and survival of carbon fuel for superbursts on accreting neutron stars : implications for mass donor evolution. The Astrophysical Journal, Vol.642 (No.1). pp. 443-454. doi:10.1086/500922

[img]
Preview
Text
WRAP_steeghs_mass_donor_evolution_0508194v2.pdf - Accepted Version

Download (522Kb) | Preview
Official URL: http://dx.doi.org/10.1086/500922

Request Changes to record.

Abstract

We have investigated the physical conditions under which accreting neutron stars in low-mass X-ray binaries can both produce and preserve sufficient quantities of carbon fuel to trigger superbursts. Our theoretical models span the plausible ranges of neutron star thermal conductivities, core neutrino emission mechanisms, and areal radii, as well as the CNO abundances in the accreted material. We find that neutron stars that accrete hydrogen-rich material with CNO mass fractions ZCNO ZCNO,☉ will not exhibit superbursts under any circumstances. Neutron stars that accrete material with CNO mass fractions 4ZCNO,☉ will exhibit superbursts at accretion rates in the observed range. On this basis, we suggest that the mass donors of superburst systems must have enhanced CNO abundances. The accreted CNO acts only as a catalyst for hydrogen burning via the hot CNO cycle, and therefore it is the sum of the three elements' mass fractions, not the individual mass fractions themselves, that is important. Systems that exhibit superbursts are observed to differ from those that do not exhibit superbursts in the nature of their helium-triggered type I X-ray bursts: the bursts have shorter durations and much greater α-values. Increasing the CNO abundance of the accreted material in our models reproduces both of these observations, thus once again suggesting enhanced CNO abundances in the mass donors. Many compact binary systems have been observed in which the abundances of the accreting material are distinctly nonsolar. Although abundance analyses of the systems that exhibit superbursts currently do not exist, Bowen fluorescence blend profiles of 4U 1636-536 and Ser X-1 suggest that the mass donor stars may indeed have nonsolar CNO metallicities. More detailed abundance analyses of the accreting matter in systems that exhibit superbursts are needed to verify our assertion that the matter is rich in CNO elements.

Item Type: Journal Article
Subjects: Q Science > QB Astronomy
Divisions: Faculty of Science > Physics
Library of Congress Subject Headings (LCSH): X-ray binaries, Neutron stars, Accretion (Astrophysics)
Journal or Publication Title: The Astrophysical Journal
Publisher: Institute of Physics Publishing Ltd.
ISSN: 0004-637X
Official Date: 2006
Dates:
DateEvent
2006Published
Date of first compliant deposit: 22 December 2015
Volume: Vol.642
Number: No.1
Page Range: pp. 443-454
DOI: 10.1086/500922
Status: Peer Reviewed
Publication Status: Published
Access rights to Published version: Restricted or Subscription Access
Funder: United States. National Aeronautics and Space Administration (NASA), Smithsonian Astrophysical Observatory
Grant number: NNG04GL38G (NASA)

Request changes or add full text files to a record

Repository staff actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics

twitter

Email us: wrap@warwick.ac.uk
Contact Details
About Us