  Magnetars are neutron stars with exceptionally strong dipole magnetic fields
which are observed to display a range of x-ray flaring behavior, but the
flaring mechanism is not well understood. The third observing run of Advanced
LIGO and Virgo extended from April 1, 2019 to March 27, 2020, and contained
x-ray flares from known magnetar SGR 1935+2154, as well as the newly-discovered
magnetar, Swift J1818-1607. We search for gravitational waves coincident with
these magnetar flares with minimally modeled, coherent searches which
specifically target both short-duration gravitational waves produced by excited
f-modes in the magnetar's core, as well as long-duration gravitational waves
motivated by the Quasi-Periodic Oscillations observed in the tails of giant
flares. In this paper, we report on the methods and sensitivity estimates of
these searches, and the astrophysical implications.
