inspection. We then folded all the peaks and the valleys into two different 401 Hz pulse profiles at the spin frequency of the neutron star (see @har08 for the ephemeris used to fold the data), and repeated the procedure for each observation where the 1 Hz QPO was detected.

The pulse phases are always consistent with being the same for peaks and valleys, within the pulse phase uncertainty of down to 0.01 cycles. The absolute pulse amplitude is higher in the peaks than in the valleys but by a smaller fraction than the mean flux, so that the pulse fractional amplitude is *always* higher in the valleys by a factor varying between 1.2 and 6 (with a typical error on the amplitude ratios of $\sim0.1$). The pulse amplitudes of peaks and valleys follow a similar evolution in time: when the pulse amplitude of peaks rises (or drops) in an observation, the same is seen for the pulse amplitude of valleys.

The valleys fractional rms amplitudes span a range between a few % rms up to more than 10 % rms, with values much larger than the average pulsed fractions of the persistent pulsation observed during the outbursts before the reflares 