Currently on sabbatical in Budapest, Hungary.

Observations of:
interstellar medium - the gas and dust between stars and galaxies, which consists of

primordial gas and stellar ejecta, and which in turn permits the creation of new stars
intergalactic medium - the gas and dust between galaxies, both in gas gravitationally

bound  in galactic haloes and in gas which is not bound to specific galaxies, but links

them  in the cosmic web       
star formation - the process by which dense parts of the interstellar medium collapse

and form stars and planets