  In this study, we employed broadband X-rays ($6-2000$ eV) to irradiate the
frozen acetone CH$_3$COCH$_3$, at the temperature of 12 K, with different
photon fluences up to $2.7\times 10^{18}$ photons cm$^{-2}$. Here, we consider
acetone as a representative complex organic molecule (COM) present on
interstellar ice grains. The experiments were conduced at the Brazilian
synchrotron facility (LNLS/CNPEN) employing infrared spectroscopy (FTIR) to
monitor chemical changes induced by radiation in the ice sample. We determined
the effective destruction cross-section of the acetone molecule and the
effective formation cross-section for daughter species. Chemical equilibrium,
obtained for fluence $2\times 10^{18}$ photons cm$^{-2}$, and molecular
abundances at this stage were determined, which also includes the estimates for
the abundance of unknown molecules, produced but not detected, in the ice.
Timescales for ices, at hypothetical snow line distances, to reach chemical
equilibrium around several compact and main-sequence X-ray sources are given.
We estimate timescales of 18 days, 3.6 and 1.8 months, $1.4\times 10^9-6\times
10^{11}$ years, 600 and $1.2\times 10^7$ years, and $10^7$ years, for the Sun
at 5 AU, for O/B stars at 5 AU, for white dwarfs at 1 LY, for the Crab pulsar
at 2.25 LY, for Vela pulsar at 2.25 LY, and for Sagittarius A* at 3 LY,
respectively. This study improves our current understanding about radiation
effects on the chemistry of frozen material, in particular, focusing for the
first time, the effects of X-rays produced by compact objects in their eventual
surrounding ices.
