  With each passing decade, we gain new appreciation for the dynamic,
connected, and often violent nature of the Universe. This reality necessarily
places the study of high-energy processes at the very heart of modern
astrophysics. This White Paper illustrates the central role of high-energy
astrophysics to some of the most pressing astrophysical problems of our time,
the formation/evolution of galaxies, the origin of the heavy elements, star and
planet formation, the emergence of life on exoplanets, and the search for new
physics. We also highlight the new connections that are growing between
astrophysicists and plasma physicists. We end with a discussion of the
challenges that must be addressed to realize the potential of these
connections, including the need for integrated planning across physics and
astronomy programs in multiple agencies, and the need to foster the creativity
and career aspirations of individual scientists in this era of large projects.
