LogN-logS simulation

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General Information

This web tool allows you to calculate a population synthesis for cooling young isolated neutron stars in the solar vicinity.

A new test for cooling curves of compact objects was proposed by Popov et al. 2006, A&A 448, 327 based on the population synthesis of close-by isolated cooling neutron stars.
Further details can be found in
The web-tool is based on the latest version of the population synthesis code (Popov et al. 2010, MNRAS 401, 2675).
We calculate the evolution of young (typically ~1Myr) close-by (<3kpc) neutron stars. For details we refer the user to Boldin et al. 2010, AN.
 

Parameters

  • Number of stars:
  • Number of simulations. We suggest to use ~5000, typically enough to avoid statistical fluctuations. In any case, please use at least a value of 100.
  • Masses and cooling curves:
  • Properties of the equation of state
     
  • Mass:
  • This is a set of neutron star masses (in solar masses) for the respective cooling curves. Masses are gravitational.
     
  • Mass fraction:
  • The mass spectrum is normalized to unity.
    The mass fraction for each bin can be defined manually or the default mass fraction can be used. In the latter case, the mass fraction for each mass specified will be calculated by the program. The final mass spectrum is available together with the final results.
     
  • Radius:
  • This is a set of neutron star radii (in cm) corresponding to the masses defined. Radii are circumferential.
     
  • Cooling curves:
  • This section defines cooling curves by calculating the temperature for each timestep as a linear interpolation between two values of the uploaded tables.
    They need to be uploaded as ASCII tables including two columns with
  • Time in years

  • Temperature in Kelvin
  •  
     

    Information on output data

    Figures

  • agedist_0_1:
  • Age distribution for neutron stars with ROSAT count rates S > 1 cts/s.
  • agedist_1_0:
  • Age distribution for neutron stars with ROSAT count rates 0.1 cts/s < S < 1 cts/s.
  • agedist_2_1:
  • Age distribution for neutron stars with ROSAT count rates 0.01 cts/s < S < 0.1 cts/s.
  • logN-logS:
  • Log N - Log S distribution and ROSAT data points with poissonian errors.
  • masspdf:
  • Mass spectrum used in the calculations.
    If the mass spectrum is defined by the user, it is re-binned for the given number of masses (up to eight). Otherwise, the default spectrum is used.
  • rdist_0_1:
  • Distance distribution for neutron stars with ROSAT count rates S > 1 cts/s.
  • rdist_1_0:
  • Distance distribution for neutron stars with ROSAT count rates 0.1 cts/s < S < 1 cts/s.
  • rdist_2_1:
  • Distance distribution for neutron stars with ROSAT count rates 0.01 cts/s < S < 0.1 cts/s.

    Data files

  • agedist_0_1:
  • Age distribution for neutron stars with ROSAT count rates S > 1 cts/s (see also corresponding figure).
    First column - age in Myr,
    second column - number of sources with the count rate S > 1 cts/s per age bin.
  • agedist_1_0:
  • Age distribution for neutron stars with ROSAT count rates 0.1 cts/s < S < 1 cts/s (see also corresponding figure).
    First column - age in Myr,
    second column - number of sources with the count rate 0.1 cts/s < S < 1 cts/s per age bin.
  • agedist_2_1:
  • Age distribution for neutron stars with ROSAT count rates 0.01 cts/s < S < 0.1 (see also corresponding figure).
    First column - age in Myr,
    second column - number of sources with the count rate 0.01 cts/s < S < 0.1 per age bin.
  • cts_N:
  • Log N - Log S data normalised to the birthrate 270 neutron stars in a Myr inside 3 kpc.
    First column - count rate,
    second column - number of sources with the count rate larger than the given value.
  • cts_Nnot:
  • galac_map:
  • Expected source distribution in galactic coordinates.
    First column - galactic longitude l in degrees,
    second column - galactic latitude b in degrees,
    third column - ...,
    fourth column - ...,
    fifth column - ... .
  • logcts_N:
  • Log N - Log S data normalised to the birthrate 270 neutron stars in a Myr inside 3 kpc.
    First column - logarithmic count rate,
    second column - number of sources with the count rate larger than the given value.
  • population_params:
  • Summary of parameters as inserted by the user.
    First column - neutron star masses in solar masses corresponding to each cooling curve,
    second column - neutron star radii in cm corresponding to each cooling curve,
    third column - mass spectrum coefficient corresponding to each cooling curve,
    fourth column - ...,
    fifth column - name of cooling curve data file as uploaded by the user.
  • rdist_0_1:
  • Distance distribution for neutron stars with ROSAT count rates S > 1 cts/s (see also corresponding figure).
    First column - distance in pc,
    second column - number of sources with the count rate S > 1 cts/s per distance bin.
  • rdist_1_0:
  • Distance distribution for neutron stars with ROSAT count rates 0.1 cts/s < S < 1 cts/s (see also corresponding figure).
    First column - distance in pc,
    second column - number of sources with the count rate 0.1 cts/s < S < 1 cts/s per distance bin.
  • rdist_2_1:
  • Distance distribution for neutron stars with ROSAT count rates 0.01 cts/s < S < 0.1 cts/s (see also corresponding figure).
    First column - distance in pc,
    second column - number of sources with the count rate 0.01 cts/s < S < 0.1 cts/s per distance bin.
     
    Code: S. Popov (SAI MSU), P. Boldin (MEPhI), B. Posselt (CfA-Harvard)
    Created: N. Tetzlaff (AIU Jena), 2008-10-20 — Last mod.: N. Tetzlaff, 2011-02-23