Molecular Content of Galaxies
2003 IRAM Summer School
by Françoise Combes
Observatoire de Paris
1. How to observe the H2 component?
why cold H2 molecule is invisible.
Infrared H2 lines, UV H2 absorption lines
CO tracer. Isotopes. Virial conditions.
CO/H2 conversion ratio
2. Molecular component of the Milky Way
Molecular surveys, distances, mapping
Spiral arms structure and contrast
Clumpiness of molecular clouds
3. H2 in external galaxies
Statistical properties, comparison with HI gas
and other tracers.
Relation to star formation
Dynamics: spiral structure, warps,
polar rings, shells, etc..
4. Molecules in absorption
in our MW, in intervening galaxies in front of QSO
Physics, chemistry, evolution as a function of z
Variation of fine-structure constant alpha
Absorption in front of PKS1830-211,
HCO+(2-1), H13CO+(2-1), (3-2),
and measurement of T(CMB) at z ~ 1