European Workshop 2004 on Astronomical Molecules: 
Dense Molecular Gas around Protostars and in Galactic Nuclei

17-20 February 2004
The Conference Building, Zwolle, The Netherlands

SUMMARY OF THE WORKSHOP

From February 17-20, 2004, over 50 astronomers from 13 countries got together
in Zwolle in Netherlands. Most of them are attending from European Institutes, 
but we recognized several delegations from Australia and South Africa. The 
workshop programme included only oral presentations without any posters. Almost 
everybody had a talk or joined discussions within a moderate number of 
participants. The atmosphere of the workshop was so friendly that young scientists 
could ask questions very frankly. We also noticed that a number of university 
staff participated the Workshop and so the workshop must be a good place for 
interaction between observatories and telescope-user communities. 

The aim of the Workshop was to discuss dense molecular gas and
masers as diagnosing tools for understanding the activity of protostars and
the central regions of active galaxies. We expected that astronomical phenomena 
observed around protostars and in galactic nuclei can be commonly explained by 
fundamental physical or chemical process. Emphasis was put on the interpretations 
and modeling of those phenomena, based on the high angular resolution and 
long-term monitoring observations. The Workshop was a meeting place of Galactic-, 
extragalactic-observers and theorists, and discussions were lively done after 
each talk, and continued during tea or lunch break. 

Overview of the potential of observing magnetic fields, the complexities, and 
what one can learn from them was made by R.Cohen. On the other hand, theoretical 
considerations for the role of magnetic fields in star formation and anticipated 
B-field structures and the evolution of the fields were made by D.Galli.
R.Cesaroni presented a number of phenomena in YSOs traced by H2O masers or 
thermal molecular lines, discriminating and testing models of inflow-outflow-disks.
Some numerical calculations on masers presented by M.Gray and J.Conway were very 
impressive. They tried to explain the observing results such as variability, 
distribution, and excitation of the masers in general. There has been some 
speculation concerning OH Megamaser (W.Baan and Y.Pihlstroem) and, in particular, 
the presence of a circumnuclear torus/ring around a nucleus. New observations and 
simulations appear to present a more realistic interpretation of what is possible 
and what is not in OHMM. 

Introductions to the complexity of chemistry and diagnostics of dense gas were 
presented by M.Hogerheijde and M.Spaans. The understanding of UV and X-ray 
radiation physics is a key to reveal the mechanism of maser excitation in 
circumnuclear regions of active galaxies. The applicability of some sub-mm lines 
for diagnostics was suggested by J.Cernicharo.
  
Monitoring methanol masers made by (S.Goedhart & M.Gaylard) increases the 
understanding of the properties of the pumping sources. Methanol maser is a new 
tool as signposts to identify spatial structures and pumping geometries 
(M.Pestalozzi and C.Phillips). Searches for new transitions and testing the 
predictive power and accuracy of a unified theory are necessary (A.Sobolev and 
M.Voronkov).

It is  recognized that observations of 22 GHz H2O masers, coupled with radio 
interferometric observations, work very well as diagnostic tools of both 
starforming regions and circumnuclear regions of active galaxies (e.g. 
J.Torrelles and L.Humphreys). 

Interpreting thermal emission of dense gas in nuclei and comparison with 
neutrals CI & CII (F.Israel) are also important to diagnose molecular 
environments. S.Aalto pointed out dangers and pitfalls of extragalactic 
molecular lines. 

The workshop participants tried to figure out of what has been observed by dense 
gas molecules, that are frequently found in the vicinity of protostars and
around galactic nuclei. Within the limitations of available observing facilities, 
it is difficult to distinguish the observed phenomena with help of numerical 
simulations. It is, however, a very important to explain what we have observed 
so far before going to the next step using ALMA and SKA.

LIST OF PARTICIPANTS SUPPORTED BY RADIONET:
                      
1.   Allard, Emma	                University of Hertfordshire,   UK
2.   de Gregorio-Monsalvo, Itziar	LAEFF-INTA,	SPAIN
3.   Knapen, Johan	                University of Hertfordshire,	UK
4.   Sobolev, Andrei	                Ural State University/MPIfR,   Russia/Germany
5.   Niezurawska, Anna	                Torun Centre for Astronomy,      Poland