Research ArticleASTRONOMY

Pinning down the superfluid and measuring masses using pulsar glitches

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Science Advances  02 Oct 2015:
Vol. 1, no. 9, e1500578
DOI: 10.1126/sciadv.1500578

Figures

  • Fig. 1 Cumulative fractional change of pulsar spin frequency at glitches over time.

    (A) Vela. (B) PSR J0537−6910. Glitch data for Vela are from (12), whereas data for PSR J0537−6910 are from Middleditch et al. (43) plus 22 new events found by Antonopoulou et al. (14). Straight lines are least-squares fit, with the average activity parameter 〈A〉 as the slope.

  • Fig. 2 Temperature dependence of neutron superfluid models as a function of baryon number density for the BSk20 nuclear equation of state.

    Thick curved lines are the superfluid critical temperature for the (labeled) models from (23). The vertical solid line indicates the separation between the crust (shaded region) and the core. Vertical dotted lines denote the density at which the superfluid moment of inertia (using the SFB superfluid model) is 1.6% of the total stellar moment of inertia for neutron stars of different mass (labeled in units of solar mass). The (nearly horizontal) dashed line is the temperature of a 1.4 MSun neutron star at an age of 11,000 years.

  • Fig. 3 Neutron star mass from pulsar observables G and interior temperature T.

    Data points are for pulsars with measured G from glitches and T from an age or surface temperature observation (see Table 1). Lines (labeled by neutron star mass, in units of solar mass) are the theoretical prediction for G and T using the BSk20 nuclear equation of state and SFB neutron superfluid models.

Tables

  • Table 1 Characteristics of glitching pulsars.
    PSRτc (103 y)A〉 (10−9 d−1)G (%)Age (103 y)Ref.Embedded Image(106 K)Ref.T (108 K)
    J0537−69104.932.43 ± 0.010.875 ± 0.0051–5(29, 30)1.9 ± 0.4
    B0833−4511.31.96 ± 0.041.62 ± 0.035.4–16(26, 27)0.93a(28)1.2 ± 0.15
    B1046−5820.41.1 ± 0.21.6 ± 0.2<1.4b(44)< 1.1
    B1338−6212.11.7 ± 0.11.5 ± 0.13–30(45)1.5 ± 0.4
    B1706−4417.81.1 ± 0.21.4 ± 0.35–18(46)0.5–0.8a(47)0.7 ± 0.2
    B1757−2415.51.5 ± 0.21.7 ± 0.3> 10(48, 49)(50)< 1.3
    B1800−2115.81.5 ± 0.21.8 ± 0.31–3b(51)Embedded Image
    B1823−1321.50.8 ± 0.11.3 ± 0.2<2b(52)< 2.2
    1E 1841−454.574 ± 11.2 ± 0.20.75–2.1(53)3b(28)2 ± 0.3

    aFrom an atmosphere spectral model.

    bFrom a blackbody spectral model.

    • Table 2 Mass, radius, and total moment of inertia of glitching pulsars for three nuclear equation of state models.
      PSRM (MSun)R (km)I (MSun km2)
      BSk20 EOS
      J0537−6910Embedded ImageEmbedded ImageEmbedded Image
      B0833−45Embedded ImageEmbedded ImageEmbedded Image
      B1046−58Embedded ImageEmbedded ImageEmbedded Image
      B1338−62Embedded ImageEmbedded ImageEmbedded Image
      B1706−44Embedded ImageEmbedded ImageEmbedded Image
      B1757−24Embedded ImageEmbedded ImageEmbedded Image
      B1800−21Embedded ImageEmbedded ImageEmbedded Image
      B1823−13Embedded ImageEmbedded ImageEmbedded Image
      1E 1841−045Embedded ImageEmbedded ImageEmbedded Image
      BSk21 EOS
      J0537−6910Embedded ImageEmbedded ImageEmbedded Image
      B0833−45Embedded ImageEmbedded ImageEmbedded Image
      B1046−58Embedded ImageEmbedded ImageEmbedded Image
      B1338−62Embedded ImageEmbedded ImageEmbedded Image
      B1706−44Embedded ImageEmbedded ImageEmbedded Image
      B1757−24Embedded ImageEmbedded ImageEmbedded Image
      B1800−21Embedded ImageEmbedded ImageEmbedded Image
      B1823−13≥ 1.71≤ 12.6≥ 88.9
      1E 1841−045Embedded ImageEmbedded ImageEmbedded Image
      APR EOS
      J0537−6910Embedded ImageEmbedded ImageEmbedded Image
      B0833−45Embedded ImageEmbedded ImageEmbedded Image
      B1046−58Embedded ImageEmbedded ImageEmbedded Image
      B1338−62Embedded ImageEmbedded ImageEmbedded Image
      B1706−44Embedded ImageEmbedded ImageEmbedded Image
      B1757−24Embedded ImageEmbedded ImageEmbedded Image
      B1800−21Embedded ImageEmbedded ImageEmbedded Image
      B1823−13Embedded ImageEmbedded ImageEmbedded Image
      1E 1841−045Embedded ImageEmbedded ImageEmbedded Image

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