3 2009 Fermi Symposium, Washington, D.C., Nov. 2-5 FIG. 2: Lightcurve of SGR J1550–5418 in various energy ranges; (a) 12 − 27 keV, (b) 27 − 50 keV, (c) 50 − 102 keV, and (d) 102 − 293 keV. The pulsations are most prominent between 50 − 102 keV (panel c, starting at ∼ 130 s). The bursts have not been removed here from the data. The dashed lines in panels (a) to (c) indicate the times of the pulse maxima. FIG. 3: Pulse profiles of SGR J1550–5418 in equal loga- rithmic energy intervals; (a) 10 − 14 keV, (b) 14 − 22 keV, (c) 22 − 33 keV, (d) 33 − 50 keV, (e) 50 − 74 keV, and (f) 74 − 110 keV. Two cycles are plotted for clarity. The ver- tical dotted and dashed lines are explained in § III B. ment. Finally, we searched for any other intervals ex- hibiting pulsed emission in the burst-free continuous CTIME data of 2009 January 22 and during the four subsequent days, using a sliding boxcar of 120 s with 10 s steps. We did not find any additional statistically- significant pulsed emission. For the entire search and for all the timing analysis reported here, we used more precise spin ephemeris obtained by contemporaneous Swift /XRT, Chandra, XMM-Newton and Suzaku ob- servations [19]. in six energy bands that have the same logarithmic width. The pulse profiles above 110 keV are consis- tent with random fluctuations, and thus not shown. B. Pulse Profiles To investigate the evolution of the pulse profiles with energy, we folded the burst-free TTE data span- ning 120 s (from T$_{0}$ +100 s to T$_{0}$ +220 s, which in- cludes the strongest pulsation period as found above) with the spin ephemeris of SGR J1550–5418. We es- timated the background level using the data segment between T$_{0}$ to T$_{0}$ +60 s. Figure 3 shows the source pulse profiles during the enhanced emission interval Figure 3 indicates that the SGR J1550–5418 pulse profiles in the three lowest energy bands are most likely complex (multi-peaked). While the two low- est energy band profiles are dominated by the struc- ture around phase 0.7-0.8 (indicated by the dotted lines in Figure 3), in the 14 − 22 keV band we see the emergence of another structure around phase 0.0 (in- dicated by the dashed lines in Figure 3). This pulse becomes equally prominent in the 22 − 33 keV range and then dominates in the 33 − 50 keV band. The pulse profile changes remarkably in the 50-74 keV band, which is the most statistically significant of all the energy bands investigated, and is distinguished by a broad structure that peaks at around phase 0.0. The 74 − 110 keV profile resembles the 50-74 keV one. As noted above, the pulse profile above 110 keV is consis- tent with random fluctuations. Therefore, our results set an observed upper energy bound of 110 keV for the hard X-ray pulsations in SGR J1550–5418 during this enhanced emission episode. eConf C091122