Barred Galaxies: Laboratories for studies of
diffuse gas
Starburst Systems: Extreme cases
Dwarf Galaxies: Small but typical
Tidal Tails: Galactic rebirth
M51: Exceedingly orderly
Our Galactic center: almost normal
A topic of special interest right now:
Intermediate Luminosity Mergers
A few details:
Infrared luminous (L(IR) > 10^11 L(sun)) and ultraluminous galaxies (ULIRGS,
L(IR) > 10^12 L(sun)) are believed to mergers of massive, gas-rich galaxies.
They are spectacular systems, related to super-starburst and Active Galactic
Nuclei (AGN) activity, attracting the attention of a large number of
researchers. Their molecular gas distribution is almost always found to be
concentrated into a few 100 pcs within the center, often in rotating disk ar
tori, while the atomic gas extends into enormous tidal tails. In the tails, tidal
dwarfs galaxies can form, and the formation of elliptical galaxies may be tied to
these cosmic fireworks.
Still, galaxies will collide and merge which do not have the necessary properties to produce spectacular ULIRGs and AGNs, either because the masses of the two progenitors are too small are unequal, or because they simply are not gas-rich enough, or because the orbital and/or internal properties of the galaxies do not allow am efficient funneling of the gas to the very heart of the merger.
These intermediate mergers and interactions also represent an ongoing change and development of the galaxies in the universe - even if the change appears more modest, it may well be the normal, more likely (and posisbly more important?) mechanism of galaxy evolution. Since the ULIRGs have captured the imagination of the majority of the researchers, these galaxy interactions remain to a large degree unexplored. Their contribution to the evolution of galaxies is not well understood - in particular not the relation to the major mergers and ULIRGs.
Knowledge of the parameters that govern the extent and efficiency of a starburst
resulting from a merger and its connection to the progenitors can onlt be gained if
the moderate luminosity mergers are investigated along with the high luminosity
counterparts. If galaxy formation at high z happened through mergers, it is essential
to understand the different types of mergers in the local unioverse, where the
systems can be resolved with present techniques.
Currently active Projects
(quite a few!)
and current collaborators, plus the telescopes we use!
A very high resolution CO map of M51
Susanne Aalto, Nick Scoville, Pat Thaddeus - OVRO interferometer
UGC 2855: The second longest gaseous bar
ever seen
Susanne Aalto, Bill Wall - OVRO interferometer, upcoming:
Calar Alto
More barred galaxies: NGC 7479 and NGC 5218
Susanne Aalto, Mousoumi Das, Bill Wall - OVRO interferometer
High density tracers in the starburst galaxy
NGC 253
Susanne Aalto, Per Bergman, Rainer Mauersberger- OVRO interferometer
IMC 0953 - a nearby tidal protogalaxy?
Sven Kohle, Christian Henkel, Jonathan Braine - IRAM
interferometer
Mrk 297: A non-central starburst in a
merger
Uli Klein, Albert Greve - IRAM interferometer
NGC 1569: molecular gas in a
post-starburst dwarf galaxy
Chris Taylor, Albert Greve, Uli Klein - IRAM interferometer
The dynamics of the molecular gas in the
Galactic center region
Wolfgang Duschl, Susanne v. Linden, Gereon Dahmen (now at
Fernbach Software S.A.)
theory, based on 1.2m CTIO and SEST
The excitation of HNCO in the Galactic
center region
Davide Rizzo, Gereon Dahmen
- SEST
The silicon isotope ratio in the
galaxy
Claudia Lemme - SEST
The oxygen isotope ratio in the Galaxy
Tom Wilson, Bill Langer, Gereon Dahmen - SEST
Highly excitad ammonia - whereever it can
be found
Christian Henkel - Effelsberg
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