  (abridged:) The Taurus Molecular Cloud (TMC) contains numerous prototypical
examples of deeply embedded protostars with massive disks and outflows,
classical and weak-lined T Tauri stars, jets and Herbig-Haro objects, and a
growing number of confirmed brown dwarfs. Star formation is ongoing, and the
cloud covers all stages of pre-main sequence stellar evolution. We have
initiated comprehensive surveys of the TMC, in particular including: (i) a deep
X-ray survey of about 5 sq. degrees with XMM-Newton; (ii) a
near-to-mid-infrared photometric survey of ~30 sq. degrees with the Spitzer
Space Telescope, mapping the entire cloud in all available photometric bands;
and (iii) a deep optical survey using the Canada-France-Hawaii Telescope. Each
wavelength regime contributes to the understanding of different aspects of
young stellar systems. XMM-Newton and Spitzer mapping of the central TMC is a
real breakthrough in disk characterization, offering the most detailed studies
of correlations between disk properties and high-energy magnetic processes in
any low-mass star-forming region, extending also to brown dwarfs in which disk
physics is largely unexplored. The optical data critically complements the
other two surveys by allowing clear source identification with 0.8 arcsec
resolution, identifying substellar candidates, and, when combined with NIR
data, providing the wavelength baseline to probe NIR excess emission. We report
results and correlation studies from these surveys. In particular, we address
the physical interpretation of our new X-ray data, discuss the entire young
stellar population from embedded protostars to weak-lined T Tau stars and their
environment, and present new results on the low-mass population of the TMC,
including young brown dwarfs.
