gas.py 文件源码

def column_density(self, rho, eph=None):
        from .core import rho_as_length

        assert isinstance(rho, u.Quantity)

        r = rho_as_length(rho, eph=eph)
        x = 0 if self.parent is None else (r / self.parent).decompose()
        y = 0 if self.daughter is None else (r / self.daughter).decompose()
        sigma = self.Q / 2 / np.pi / r / self.v
        if self.daughter is None or self.daughter == 0:
            sigma *= np.pi / 2 - self._iK0(x)
        elif self.parent is None or self.parent == 0:
            sigma *= np.pi / 2 - self._iK0(y)
        else:
            sigma *= (self.daughter / (self.parent - self.daughter)
                      * (self._iK0(y) - self._iK0(x)))

        return sigma.decompose()