Malcolm Walmsley Arcetri, Italy

Title: The Physical Structure of Star forming Regions

Star forming regions are first and foremost defined by the fact that gravitational energy is comparable to the sum of kineticenergy in turbulent or systematic motions (such as rotation) andthermal energy. We know that stars form in "cores" in molecularclouds satisfying the above condition. They may also satisfythe condition that the magnetic and gravitional energies arecomparable but this is disputed and I will discuss briefly thetwo sides of this discussion. It is in any case essential todetermine the run of temperature and density in these objects andI will discuss some ways of doing this. Gas and dust temperaturefor instance are likely coupled at high density but belowdensities of roughly 10^{5} cm-3, dust-gas collisions are nolonger fast enough and other processes take over. It is alsocritical in the case of a magnetic field dominated contraction todetermine the ionization degree of the gas and hence theambipolar diffusion timescale. Finally, a critical question isto what extent and how the dust grains grow in the "prestellar"phase before a protostar forms. I will discuss what one knowsabout these questions . Eventually, a protostar forms surrounded by a disk, heats the(presumably) infalling envelope, andproduces a bipolar flow. One of the most intriguing questionsis how the physical conditions in the envelope and the disk massevolve as a function of time. What is clear is that the result ofthis evolution is (for low mass stars, at higher mass the storyis different) a "Classical T Tau" or pre-main-sequence star surroundedby a disk of order 100 AU in radius. If there is time, I maybriefly discuss the physical conditions in this latter state.Again, grain growth (which eventually is thought to produceplanets) plays a key role in determining what we observe.

Paola Caselli Arcetri, Italy

Title: Chemical Processes in Star Forming Regions

In this talk I shall review the basic chemical processes in dense molecular clouds, where low mass and high mass stars form. First, the chemistry of cold pre-stellar cloud cores, where molecular freeze-out and deuterium fractionation dominate, will be presented. Then, following cloud evolution after protostellar birth, hot core and shock chemistry will be discussed in view of recent observations. A brief summary of the chemistry in protoplanetary disks will also be furnished. The aim is to identify important gas tracers in the various steps of the star formation process, pointing out the importance of the next generation telescopes.

Anthony Whitworth
Cardiff, UK

Title: Theory of star formation

I will discuss the basic theory of star formation, emphasizing the role of dynamical triggering and concentrating on basic physical processes. My talk will consider such questions as (i) the mechanisms which (we believe) determine the initial mass function and the efficiency of star formation, (ii) the formation of binaries and planets, and (iii) the origin of brown dwarves. I will illustrate my talk with numerical simulations.

Phil Myers Harvard-Smithsonian Center for Astrophysics, Cambridge,MA, USA

Title: Initial conditions of star formation

We review recent developments in molecular clouds and in the formation of stars in isolation and in clusters. Isolated stars tend to form in centrally condensed cores with “flat-top” density profiles. These profiles can be fit by detailed models of spherical isothermal equilibrium. However, models with significant roles for turbulence, magnetic fields, collapsing motions and asphericity may also match, especially in the outer parts of cores. “Infall asymmetry” seen in numerous spectral lines indicates subsonic inward motions, possibly increasing inward as expected from gravity-driven models. “Prestellar” cores like L1544 have high column densities, freeze-out on grains, high deuteration, high infall speeds, and appear to be the most evolved starless cores. Such cores may not be the only path to isolated star formation, since the Spitzer Space Telescope has revealed very low-mass protostars in much less dense cores such as L1014. Cores differ from isolated to cluster-forming regions, where they are more numerous, denser, warmer, more turbulent, more chemically diverse, and where their environment may have a flatter geometry. A flat geometry may account for the high proportion of dense gas and the high mass accretion rates in cluster-forming regions.

Mario Tafalla OAN, Madrid, Spain

Title: Starless Cores

Starless dense cores are the simplest sites of star formation, and their study is expected to reveal the basic physics of stellar birth. For a number of years, however, the study of dense cores has been plagued by conflicting results from observations made using different molecular tracers, and this has precluded achieving a consistent picture of their internal structure. The recent realization that dense cores have a highly differentiated chemical composition has resolved many of the old conflicts, and is permitting rapid progress in characterizing these systems. In this talk I will show how by modeling self-consistently the emission of dense cores we are starting to determine both their physical and chemical structure. By doing so we can study intrinsic differences between cores, and from there start to reconstruct their evolution from diffuse cloud material to the verge of gravitational instability.

Rafael Bachiller
Observatorio Astronomico Nacional (IGN), Spain

Title: The early evolution of bipolar outflows and prospects for outflow research with ALMA

Bipolar outflows from forming stars are particularly energetic at the earliest protostellar stages. In fact, soon after the "Class 0" phase the outflow mechanical power declines and the strong outflow-induced chemical anomalies dissipate. This evolution is very rapid and pooly understood so far. I will present some very recent results from an extensive survey aimed to study the rapid early evolution of protostellar bipolar outflows. >From homogeneous observations of a relatively large sample of outflows, we are able to reconstruct important aspects of the outflow evolution and of the associated chemical alterations. I will also provide some prospects for outflow research with the Atacama Large Millimeter Array (ALMA).

Francesca Bacciotti
Arcetri, Italy

Title: Protostellar Jets

In the last few years new investigation techniques have allowed us to study in deep the spectacular phenomenon of protostellar jets, and to test the validity of the proposed models for their launch and propagation. In this contribution I will review the current knowledge on the subject, with a special emphasis on the recent achievements obtained thanks to observations at high angular resolution, like those performed at subarcsecond scales with the Hubble Space Telescope and with Adaptive Optics techniques. These results have made us able to define more clearly the morphology, kinematics, excitation of the flows on small scales, and, in turn, to derive stringent constraints for the physical processes at work. This novel information, collected very recently, puts us in a very good position to plan rich and fruitful observative campaigns with the instruments being developed for astronomy at IR, submm amd mm wavelengths, in interferometric or single-telescope mode.

Leonardo Testi Arcetri, Italy

Title: Circumstellar disks and the dawn of planetary systems

I will discuss the properties of circumstellar disks across the stellar mass range as derived from millimeter interferometric observations. Millimeter observations also allow us to probe the evolution of circumstellar disks properties as a function of the age of the system setting the stage for the planets fromation process.

Michael R. Meyer
Department of Astronomy/Steward Observatory, The University of Arizona, USA

Title: Formation and Evolution of Planetary Systems: Placing Our Solar System in Context

Over the past 15 years abundant evidence has emerged that many (if not all) stars are born with circumstellar disks. While concensus is emerging concerning the the early evolution of accretion disks (tau < 10 Myr) and the characterization of older debris disks (tau > 1 Gyr) continues at a rapid pace, little is known about the transition between these two extremes thought to occur during the epoch of planet formation. The goals of our Spitzer Legacy Science Program are to trace the evolution of planetary systems from: (1) 3-10 Myr when stellar accretion from the disk terminates; through (2) 10-100 Myr when planets achieve their final masses via coalescence of solids and accretion of remnant molecular gas; to (3) 100-3000 Myr when the final architecture of solar systems takes form and collisions between remnant planetesimals produce observable quantities of dust. Our strategy is to use carefully calibrated spectral energy distributions and high- resolution spectra to infer the radial distribution of dust and gas surrounding a sample of 330 solar-like stars distributed uniformly in log- age over 3 Myr to 3 Gyr. This approach should provide insight into the diversity of planetary system architectures, contraining the range of possible outcomes of the planet formation process - thus helping to place our own solar system in context. We will report on the latest results from our program.

Riccardo Cesaroni Arcetri, Italy

Title: Disks around massive stars

Current evidence for the existence of rotating disks in high-mass (proto)stars will be reviewed and the implications on the formation mechanism of O-B stars will be discussed, illustrating how such disks may help discriminating between two proposed formation scenarios: accretion and coalescence.

Henrik Beuther
Harvard-Smithsonian Center for Astrophysics, Cambridge,MA, USA

Title: Outflows from massive young stars

Massive molecular outflows are known to be as ubiquitous in high-mass asin low-mass star formation. However, because of the cluster mode ofmassive star formation and the increased energetics of such regions,observations of high-mass outflows appear somehow different - at least atlow-spatial resolution. I will present the current state of massiveoutflow research with special focus on interferometrichigh-spatial-resolution observations. Similarities and differences totheir low-mass counterparts will be presented. Finally, I am going tooutline a tentative evolutionary scenario for massive molecular outflows.

Cathie Clarke
Institute for Astronomy, Cambridge, UK

Title: The Dispersal Of Discs around Young Stars

It is well known that discs around young stars have typicallifetimes in the range $1-10$ Myr and that they make the transitionbetween disc possessing status and discless status on a considerablyshorter timescale ($\sim 10^5$ years). In addition it is knownthat there is a large dispersion of disc lifetimes for discsin a given region, so that some aspect of the formation processendows discs with a survival clock that varies from star to star. The coming decade however heralds a number of observationalfacilities that will provide considerably more information onwhy and how discs disperse. Spitzer is extending the spectral energydistributions of T Tauri stars into the mid infrared regime andis providing important evidence of systems that have cleared theirinner discs but retain cooler material at larger radii. LikewiseALMA and optical interferometric arrays hold out the prospectof imaging the inner regions of T Tauri discs, whilst the spectroscopicdetection of {\it gas} in inner discs is beginning to allowdirect determinations of how the dust to gasratio evolves as discs disperse. The standard paradigm is that evidence of inner disc clearingis almost tantamount to the detection of planet formation. However,this is not a unique interpretation, as other dispersal mechanismsalso clear the disc from the inside out. I will describe howtheory and observation are developing in this area and whatwill be the key observations of the next few years that mayhelp to distinguish between various theoretical possibilities. Whatever the outcome, it is clear that the answer will have profound implications for planet formation scenarios - do planets self-limitthe lives of their parent discs or is planet formation a processthat occurs in competition with some independent dispersal mechanism?

Jonathan Tan
Dept of Astrophysical Sciences, Princeton, NJ, USA

Title: Clustered Star Formation: Overview of Theory

I review some of the important questions that must be answered before we can claim to have a comprehensive understanding of the formation of star clusters and the formation of stars within clusters. First I describe theoretical and observational progress in understanding how the initial high-density, high-pressure gas clumps, i.e. protoclusters, are formed in GMCs. Then I show how individual star formation in clusters can be understood using the traditional model of isolated star formation, but modified to account for high ambient pressures.

Anne-Katharina Jappsen Astrophysikalisches Institut Potsdam

Title: Mass Spectra from Gravoturbulent Fragmentation

One of the major uncertanties in identifying the processes that determine the initial mass function (IMF) of stars is the exact chemical state of the star forming gas and its influence on the dynamical evolution. We study the effects of a piecewise polytropic equation of state on the formation of stellar clusters in turbulent, self-gravitating molecular clouds using three-dimensional, smoothed particle hydrodynamics simulations.

Charles Lada Harvard-Smithsonian Center for Astrophysics, USA

Title: Measuring The Initial Mass Function in Embedded Clusters

Andre Moitinho
OAL, Lisboa, Portugal

Title: Pre-main-sequence evolution and brown dwarfs beyond the solar vicinity

Most of what is known about pre-main-sequence (PMS) evolution and brown dwarfs (BD) is based on results for nearby (up to a few hundreds of parsecs) star formation regions. Although close, observations of these regions are in general compromised by variable amounts of dust and nebular contamination which affect not only the derived properties of individual objects, but also bias the samples of members. Avoiding these problems forces us to look out to farther regions, something that is now becoming possible with the new generations of telescopes. In this contribution, I present new VLT observations in the V and I bands which uncover the low mass PMS stars and BDs of the 5 Myr open cluster NGC2362. This cluster is located at 1480 pc and is not affected by the problems mentioned above, which makes it a privileged target for studying not only PMS evolution and BDs but also offers a valuable opportunity to study the IMF well down into the substellar regime.

Rafael Rebolo
Instituto de Astrofisica de Canarias, Tenerife, Spain

Title: Brown dwarfs: facts and challenges

Brown dwarfs are possibly more numerous than stars. Discovered less than ten yers ago, these ubiquitous objects appear to be rather enigmatic. We will discuss the observational properties of brown dwarfs in star clusters, in the general field and around stars, possible formation mechanisms and basic aspects of their structure and evolution.

Ray Jayawardhana
University of Toronto, Canada

Title: Shedding Light on Brown Dwarf Origins

I will report on recent progress in investigating young brown dwarfs, and discuss the prospects for the next generation of telescopes to further our understanding of the origin and early evolution of sub-stellar objects.

Melvin Hoare
University of Leeds, UK

Title: High Resolution Views of Massive Young Stellar Objects

High resolution observations of several massive young stellar objects at a variety of wavelengths will be presented. In particular, maps of the radio continuum emission from the stellar winds reveal that some objects drive winds in a predominately equatorial direction, perpendicular to the large scale bipolar outflow. This suggests that an accretion disc is feeding the ionised flow. High resolution observations in the millimetre, mid-IR and near-IR will be shown with the aim of searching for evidence of discs and the expected surrounding flattened structure in the infalling material.

M. S. Nanda Kumar Centro de Astrofisica da Universidade do Porto

Title: Massive Protostars and Small Proto-Clusters

I will discuss a 2MASS study of 215 candidate massive protostars which include a sample of both pre-UCHII and UCHII phases. We have conducted a systematic study of clustering associated with these massive protostars which reveal 54 embedded clusters. The results indicate that massive star birth begins atleast about 0.5-1 million years after low mass star birth begins in these small groups/clusters. Color-color diagrams of near-infrared counterparts of millimeter peaks (associated with massive protostars) show color excess much more than that enclosed by the HAeBe curves. I will present recent multiwavelength observations that show H2 emission close to the stellar source in the form of rings and disks which support winds/shock activity in the equatorial plane of massive protostars. The (proto)clusters associated with massive protostars appear to be simple and neat laboratories to study the formation of such clusters. I will discuss the detailed infrared and molecular line observations of two peculiar ring shaped clusters discovered from this larger sample. These ring shaped clusters show striking similarities to the theoretical predictions of small cluster formation.