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XMM-Newton Science Analysis System


ssclib (ssclib-3.29) [xmmsas_20060628_1801-7.0.0]

Meta Index / Home Page / A module which contains / Black Body routines

Per unit frequency

The precision at low frequencies f is limited by the calculation of exp(x)-1, where x = hfk/T. At low values of x, exp(x) is close to 1 and thus the difference between exp(x) and 1 is a number of low precision. Thus for x values less than 0.1, a series expansion of (exp(x)-1)/x is used instead. The minimum precision occurs at x = 0.1 and is approximately equal to precision(1d0)-1.

  subroutine getBBfluxPerHertz(hertzValues, kelvin, powerValues)
    real(double), intent(in)  :: hertzValues(:), kelvin
    real(double), intent(out) :: powerValues(size(hertzValues))
  end subroutine getBBfluxPerHertz

  function bbFluxPerHertz(hertz, kelvin) result(power)
    real(double), intent(in) :: hertz, kelvin
    real(double)             :: power
  end function bbFluxPerHertz