A few years ago, a motivation for organizing one more IAU Symposium on star for­ mation in Grenoble, was the anticipated completion of the IRAM interferometer on the Plateau de Bures, close to Grenoble. This choice was also a sort of late celebration of the genius of Joseph Fourier, born in Grenoble, whose work is the very fondation of in­ terferometry. At the time when we finally announced the advent of this conference, the first reactions we got from the community were expressions of saturation and even reject, the Symposium being unfortunately scheduled almost simultaneously as two other major meetings on closely related topics, and sponsored by different organizations. A wave of disappointment then reached the organizers. Some of us were enthusiastic enough to help the others overcome their discouragement. Let them be thanked here. There was, indeed, a deeper motivation for organizing this conference. It was to trigger the meeting and communication of physicists and astrophysicists since many of the difficulties met now in understanding the physics of the interstellar medium and its evolution toward star formation are common to several, if not most, other fields of physics. They are assigned to one origin: complexity.

Inhalt

Large Scale Structure.- Characteristics of the diffuse interstellar medium.- On the structure and kinematics of molecular clouds from large scale mapping of mm-lines.- Observational manifestations of sequential star formation in giant star-gas complexes of the Galaxy.- A CS survey of massive stars embedded in molecular clouds.- Diffuse molecular clouds at high galactic latitude.- The atomic hydrogen/molecular cloud association: an unavoidable relationship.- Velocity Field and Magnetic Field.- Magnetic fields in dense regions.- Structure in the gas and magnetic field in S106.- The investigation of the hierarchical structure of the interstellar magnetic fields.- Loss of magnetic flux and angular momentum from molecular clouds.- Magnetic fields and the dynamics of molecular clouds.- Turbulence and magnetic fields in molecular clouds.- Dynamical conditions of dense clumps in dark clouds: a strategy forelucidation.- Numerical simulations of turbulent compressible flows.- Signatures of turbulence in the dense interstellar medium.- Chemistry.- Chemistry and small-scale structure of diffuse and translucent clouds.- Variations in the abundance of small particles.- Physical and chemical parameters in dense cores.- Abundance variations of tracers and their effects on our determination of molecular cloud structure.- Shocks and Instabilities.- Magneto-Hydrodynamic shock waves in molecular clouds.- Thermal processes in molecular gas.- On the origin of broad line wings in molecular cloud spectra.- The development of modes of thermal instability in a non-stationary medium.- Large-scale fragmentation of gas cloud rotating at the Galactic center.- Small Scale Structure.- Clouds, cores and stars in the nearest molecular complexes.- Dense core structure and fragmentation in the Rho Ophiuchi molecular cloud.- UV penetrated clumpy molecular cloud cores.- Dust emission from star forming clouds: a progress report.- Star Formation.- Some processes influencing the stellar initial mass function.- A comparative study of star formation efficiencies in nearby molecular cloud complexes.- Luminosity function, star density and star formation efficiency in regions of star formation.- Star formation in three nearby molecular cloud complexes.- Wave dynamics and star formation in Taurus.- Early Stages of Stellar Evolution.- Theoretical and observational aspects of young stars of intermediate mass.- A survey of circumstellar structure around young low mass stars.- Aperture synthesis CS and 98 GHz continuum observations of protostellar IRAS sources in Taurus.- Aperture synthesis observations of Orion-KL in CS lines and 3 mm continuum.- A 45 AU radius source around L1551-IRS5: a possible accretion disk.- Strong magnetic fields in bipolar outflows.- Poster Sessions.- Symposium summary.- High-velocity molecular bullets in bipolar outflows:L1448 and HH7-11.- The effects of ionizing radiation on star formation in molecular clouds.- Transfer of continuum UV radiation inside fragmented clouds.- Do random velocity fields inhibit or induce gravitational collapse and fragmentation ?.- Fragmentation in molecular clouds.- Velocity correlations in turbulent molecular clouds.- MHD instabilities and fragmentation of molecular clouds.- A multi-transition and multi-isotope study of CO in the giant molecular cloud Orion-A.- Processes controlling the initial mass function: interstellar turbulence and magnetic fields.- Effects of the UV radiation on the surrounding gas and dust.- High resolution infrared maps of IRAS galaxies.- Interpretation of low J 12CO and 13CO observations of Orion A by means of an onion-shell radiative transfer model.- Global properties of star formation in Taurus.- Polarization of background starlight and the structure of the interstellar magnetic field.- First detection of 661 GHz 13CO J=6-5: large amounts of warm molecular gas.- The mass distribution of the young stellar population in Chamaeleon I and in Rho Ophiuchus.- Dense cloud cores.- Gravitational instability induced by collisions between non-identical clouds.- CO multitransition observations of L 1228: A molecular outflow destructing its parent cloud ?.- Ammonia clumps in the Orion and Cepheus clouds.- Observational constraints on angular momentum transfer during gravitational collapse.- Megamasers as probes of galaxy mass spectrum evolution.- Magnetic fields in the Solar Nebula and the angular momentum transfer.- Physical conditions of star forming sites in the S247/252 molecular complex.- Hierarchical fragmented structure of molecular clouds produced by supersonic turbulence.- The bipolar flow phenomenon.- A hydrodynamical model for the fragmentation of the W49A star-forming region.- CO line broadening by saturation effect in molecular clouds.- The high latitude cloud Lynds 1642 is not breaking up.- Large scale interaction of the outflow and quiescent gas in Orion.- Physical parameters in extragalactic star forming regions.- An 8" resolution CO (J=3-2) map of IC 342.- A large scale survey of dense cores and molecular outflows in Ophiuchus.- A hydrodynamical study of fragmenting gas clouds.- New Sample of Young Stellar Objects.- Comparison of turbulence in HII regions and molecular clouds.- Fragmentary structure in the L1551 molecular outflow.- Observations of variability of H20 Maser sources associated with star formation regions.- A model of the distribution of ionised carbon in M17SW.- Estimates of magnetic fields in interstellar gas clouds from 18-cm OH satellite lines.- 15NH3 millimasers toward NGC 7538-IRS1.- A very straight and collimated outflow in the core of OMC-1.- Density and kinematics of the W49A cloud core.- Synthetic linemaps for hierarchical clouds.- Bright-rimmed clouds with IRAS point sources: candidates for star formation by radiation-driven implosion.- Density structure of dense cores in the Cepheus molecular cloud.- Turbulence in TMC1-C and Rho Oph core.- Radiative transfer of CO through clumpy molecular clouds with external UV heating.- Characterisation of spatial structure in molecular clouds.- Measuring the fractal structure of interstellar clouds.- The W75-Cygnus-X IRAS loop: OB "Bubble" or SNR?.- An extensive study of interstellar matter in the IC 1396 region using several molecular lines and transitions of CO and far-infrared maps from IRAS.- Gravitational virialization of molecular cloud fragments.- Turbulent amplification of interstellar magnetic fields.- Cloud-Cloud collisions and fragmentation.- A binary star formation mechanism through the fragmentation of prolate dense cores rotating end over end.- Color-Plates.- Indices.