  A novel method for analyzing the intermittent behavior of linear response
data in aging systems is presented and applied to spin-glass thermoremanent
magnetization (TRM) (Rodriguez et al. Phys. Rev. Lett. 91, 037203, 2003).
  The probability density function (PDF) of magnetic fluctuations is shown to
have an asymmetric exponential tail, demonstrating that the demagnetization
process is carried by intermittent, significant, spin rearrangements or
\emph{quakes}. These quakes are most pronounced shortly after the field
removal, $t/t_w \approx 1$ and in the non-equilibrium aging regime $t/t_w >>1$.
For a broad temperature range, we study the dependence of the TRM decay rate on
$t$, the time since the initial quench and on $t_w$, the time at which the
magnetic field is cut. The $t$ and $t_w$ dependence of the rate is extracted
numerically from the data and described analytically using the assumption that
the linear response is subordinated to the intermittent process which
spasmodically release the initial imbalances created by the quench.
