IDEAS home Printed from https://ideas.repec.org/a/nat/nature/v420y2002i6911d10.1038_nature01159.html
   My bibliography  Save this article

Gravitationally redshifted absorption lines in the X-ray burst spectra of a neutron star

Author

Listed:
  • J. Cottam

    (NASA Goddard Space Flight Center, Laboratory for High Energy Astrophysics)

  • F. Paerels

    (Columbia University)

  • M. Mendez

    (SRON National Institute for Space Research)

Abstract

The fundamental properties of neutron stars provide a direct test of the equation of state of cold nuclear matter, a relationship between pressure and density that is determined by the physics of the strong interactions between the particles that constitute the star. The most straightforward method of determining these properties is by measuring the gravitational redshift of spectral lines produced in the neutron star photosphere1. The equation of state implies a mass–radius relation, while a measurement of the gravitational redshift at the surface of a neutron star provides a direct constraint on the mass-to-radius ratio. Here we report the discovery of significant absorption lines in the spectra of 28 bursts of the low-mass X-ray binary EXO0748-676. We identify the most significant features with the Fe xxvi and xxv n = 2–3 and O viii n = 1–2 transitions, all with a redshift of z = 0.35, identical within small uncertainties for the respective transitions. For an astrophysically plausible range of masses (M ≈ 1.3–2.0 solar masses; refs 2–5), this value is completely consistent with models of neutron stars composed of normal nuclear matter, while it excludes some models6,7 in which the neutron stars are made of more exotic matter.

Suggested Citation

  • J. Cottam & F. Paerels & M. Mendez, 2002. "Gravitationally redshifted absorption lines in the X-ray burst spectra of a neutron star," Nature, Nature, vol. 420(6911), pages 51-54, November.
    • Handle: RePEc:nat:nature:v:420:y:2002:i:6911:d:10.1038_nature01159
    DOI: 10.1038/nature01159
    as

    Download full text from publisher

    File URL: https://www.nature.com/articles/nature01159
    File Function: Abstract
    Download Restriction: Access to the full text of the articles in this series is restricted.
    File URL: https://libkey.io/10.1038/nature01159?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:nat:nature:v:420:y:2002:i:6911:d:10.1038_nature01159. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    We have no bibliographic references for this item. You can help adding them by using this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Sonal Shukla or Springer Nature Abstracting and Indexing (email available below). General contact details of provider: http://www.nature.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.