Swift discovered GRB 050713A and slewed promptly to begin observing with its
narrow field instruments 72.6 seconds after the burst onset, while the prompt
gamma-ray emission was still detectable in the BAT. Simultaneous emission from
two flares is detected in the BAT and XRT. This burst marks just the second
time that the BAT and XRT have simultaneously detected emission from a burst
and the first time that both instruments have produced a well sampled,
simultaneous dataset covering multiple X-ray flares. The temporal rise and
decay parameters of the flares are consistent with the internal shock
mechanism. In addition to the Swift coverage of GRB 050713A, we report on the
Konus-Wind (K-W) detection of the prompt emission in the energy range 18-1150
keV, an upper limiting GeV measurement of the prompt emission made by the MAGIC
imaging atmospheric Cherenkov telescope and XMM-Newton observations of the
afterglow. Simultaneous observation between Swift XRT and XMM-Newton produce
consistent results, showing a break in the lightcurve at T+~15ks. Together,
these four observatories provide unusually broad spectral coverage of the
prompt emission and detailed X-ray follow-up of the afterglow for two weeks
after the burst trigger. Simultaneous spectral fits of K-W with BAT and BAT
with XRT data indicate that an absorbed broken powerlaw is often a better fit
to GRB flares than a simple absorbed powerlaw. These spectral results together
with the rapid temporal rise and decay of the flares suggest that flares are
produced in internal shocks due to late time central engine activity.Comment: 22 pages, 6 tables, 10 figures; Submitted to the Astrophysical
Journa