| Description |
In the local universe, most of the observable matter is contained in
stellar objects shaping the morphology and dynamics of their parent
galaxy. In view of the dominance of stellar mass, a better
understanding of star formation and its consequences is mandatory and
forms a central topic of contemporary astrophysical research. There
exist a large number of high linear resolution studies related to
individual star forming regions of the Galaxy as well as of low linear
resolution studies of external galaxies. For a complete view onto the
physical and chemical processes driving star formation and galactic
evolution it is, however, essential to combine local conditions
affecting individual star formation with properties only becoming
apparent on global scales.
The optimal target providing such a complete view is
a galaxy that is actively forming stars, that is not
seen edge-on (like our Galaxy), that has been studied
at radio, optical and X-ray wavelengths, and that is
sufficiently nearby to also permit studies on small
scales. For our carefully chosen template galaxy, we
plan to use HIFI to obtain fully-sampled large-scale
CII (and H2O) maps. PACS will add important
interstellar cooling lines, OI, NII, NIII.
And SPIRE & PACS will be used to map the dust spectral
energy distribution over the entire galaxy.
Observing a deep, extended strip along the major
axis of our template galaxy M33, will allow us to
study the ionized, atomic, and molecular phases
of the interstellar medium, its life cycle and
thermal balance, tracing the formation
of molecular clouds and of stars. Aside of insights
related to the local processes in the galaxy itself,
the mapped source will set a standard, providing a
basis for the interpretation of phenomena encountered
in other targets of the Local Group and in more
distant galaxies. |
