EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 426/1 Article
Free access article

Issue A&A
Volume 426, Number 1, October IV 2004
Page(s) 267 - 277
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20040455



A&A 426, 267-277 (2004)
DOI: 10.1051/0004-6361:20040455

Temperature distribution in magnetized neutron star crusts

U. Geppert1, M. Küker1 and D. Page2

1  Astrophysikalisches Institut Potsdam An der Sternwarte 16 14482 Potsdam, Germany
    e-mail: urme@aip.de
2  Instituto de Astronomía, UNAM, 04510 Mexico DF, Mexico

(Received 16 March 2004 / Accepted 2 July 2004)

Abstract
We investigate the influence of different magnetic field configurations on the temperature distribution in neutron star crusts. We consider axisymmetric dipolar fields which are either restricted to the stellar crust, "crustal fields", or allowed to penetrate the core, "core fields". By integrating the two-dimensional heat transport equation in the crust, taking into account the classical (Larmor) anisotropy of the heat conductivity, we obtain the crustal temperature distribution, assuming an isothermal core. Including classical and quantum magnetic field effects in the envelope as a boundary condition, we deduce the corresponding surface temperature distributions. We find that core fields result in practically isothermal crusts unless the surface field strength is well above 1015 G while for crustal fields with surface strength above a few times 1012 G significant deviations from crustal isothermality occur at core temperatures inferior or equal to 108 K. At the stellar surface, the cold equatorial region produced by the suppression of heat transport perpendicular to the field by the Larmor rotation of the electrons in the envelope, present for both core and crustal fields, is significantly extended by that classical suppression at higher densities in the case of crustal fields. This can result, for crustal fields, in two small warm polar regions which will have observational consequences: the neutron star has a small effective thermally emitting area and the X-ray pulse profiles are expected to have a distinctively different shape compared to the case of a neutron star with a core field. These features, when compared with X-ray data on thermal emission of young cooling neutron stars, would provide a first step toward a new way of studying the magnetic flux distribution within a neutron star.


Key words: stars: neutron -- stars: magnetic fields -- conduction -- dense matter -- X-rays: stars

SIMBAD Objects



© ESO 2004


What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.