Letter to the Editor

The cooling neutron star in 3C 58

¹ Ioffe Physical Technical Institute, Politekhnicheskaya 26, 194021 St. Petersburg, Russia e-mail: kam@astro.ioffe.rssi.ru
² N. Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw, Poland e-mail: haensel@camk.edu.pl
³ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA e-mail: ognedin@stsci.edu

Corresponding author: D. G. Yakovlev, yak@astro.ioffe.rssi.ru

Received: 15 April 2002
Accepted: 13 May 2002

Abstract

The upper limit on the effective surface temperature of the neutron star (NS) PSR J0205+6449 in the supernova remnant 3C 58 obtained recently by Slane et al. ([CITE]) is analyzed using a modern theory of NS cooling (Kaminker et al. [CITE]). The observations can be explained by cooling of a superfluid NS with the core composed of neutrons, protons, and electrons, where direct Urca process is forbidden. However, combined with the data on the surface temperatures of other isolated NSs, it gives evidence (emphasized by Slane et al.) that direct Urca process is open in the inner cores of massive NSs. This evidence turns out to be less stringent than that provided by the well known observations of Vela and Geminga.