Astronomy is in a golden age of discovery of the new, with a growingappreciation from astrophysics that physics has studied so far analmost insignificant fraction of reality. This golden age is enabledby technology, with next generation technologies approaching theGiga-euro/dollar investment level. This forces a strategic view of relativestrengths in the past, and strategies for future developments. Some ofthese may transcend traditional wavelength classifications.


We review the evolution of the interstellar medium in disk galaxies, and show, both analytically and by numerical 3D hydrodynamic simulations, that the disk-halo connection is an essential ingredient in understanding the evolution of star forming galaxies. Depending on the star formation rate of the underlying gaseous disk, a galactic fountain is established. If the star formation rate is sufficiently high and/or cosmic rays are well coupled to the thermal plasma, a galactic wind will be formed and lead to a secular mass loss of the galaxy. Such a wind leaves a unique imprint on the soft X-ray spectra in edge-on galaxies, with delayed recombination being one of its distinctive features. We argue that synthetic spectra, obtained from self-consistent dynamical and thermal modeling of a galactic outflow, should be treated on an equal footing as observed spectra. We show that it is thus possible to successfully fit the spectrum of the starburst galaxy NGC 3079

The accuracy with which it is possible to calculate theoretically the positions ofenergy levels and the low density (in frequency) of the grid on which opacity sampling is calculated bothlimit the accuracy with which the effect ofblends can be determined. For species such as Fe for which a large number of transitionsare involved in calculations, this leads to a small effect since, statistically, cancellations occur. However the effect can be large for an element such as Li with only a few transitions contributing to its radiative acceleration, grad(Li), at any given stellar radius. In particular, the Fe lines are shown to modify grad(Li) in and below the Fe convection zone but the modification depends on Fe level positions.This is analyzed quantitatively here using the OPAL data base. The grad(Li) are found to be uncertain by a factor of 2 in Pop I stars but of 1.03 in Pop II stars.

The wealth of data in the past decades, and especially in the past 15 years has transformed our picture of the gas around the Milky Way and other spiral galaxies. There is good evidence for extraplanar gas that is a few kpc in height and is seen in all gaseous phases: neutral; warm atomic; and hot, X-ray emitting gas. This medium is seen not only around the Milky Way, but other spiral galaxies and it is related to the star formation rate, so it is likely produced by the activity in the disk through a galactic fountain. More extended examples of halo gas are seen, such as the HVC around the Milky Way and around M 31. This gas is typically 10–20 kpc from the galaxy and is not seen beyond 50 kpc. This gas is most likely being accreted. A hot dilute halo (106 K) is present with a similar size, although its size is poorly determined.

An ongoing controversy surrounds the relative amounts of outflow from the disk and accretion onto galaxies such as the Milky Way. There is good evidence for accretion of cold material onto the Milky Way and other galaxies, but it is not clear if there is enough to modify the gas content and star formation properties in the disk. The reservoir of accretion material is as yet unidentified. Some of these findings may be related to the issue that galaxies are baryon-poor: their baryon to dark matter ratio is well below the cosmological value. The absence of baryons may be due to extremely violent outflow events in the early stages of galaxy formation. We may be able to understand this stage of galaxy evolution by applying our deepening understanding of our local disk-halo environment.

Due to the recent interest shown by astronomers towards the Antarctic Plateauas a potential site for large astronomical facilities, we assistedin the last years to a strengthening of site testing activities in this region, particularly at Dome C. Most of the results collected so far concern meteorologic parameters and optical turbulence measurements based on different principles using different instruments. At present we have several elements indicating that, above the first $20{-}30$ m, the quality of the optical turbulence above Dome C is better than above whatever other site in the world. The challenging question, crucial to know which kind of facilities to build on, is to establish how much better the Dome C is than a mid-latitude site. In this contribution we will provide some complementary elements and strategies of analysis aiming to answer to this question. We will try to concentrate the attention on critical points, i.e. open questions that still require explanation/attention.

During its mission Gaia will give access to a so far never reached astrometric accuracy of a large number of Solar System objects. Nevertheless some of these Gaia observations could be efficiently completed by ground-based observations. This will allow us to get a better understanding of the dynamical and physical properties of these objects. We present a general overview of these cases.

Magnetic fields have been detected at the surface of many stars, where they are responsible for various activity phenomena, and presumably they are present also in their deep interior. They channel stellar winds to large distance, thus increasing the loss of angular momentum. In stably stratified radiation zones, they tend to impose uniform rotation, and may thus interfere with the rotational mixing operating in these regions and influence the evolution of the host star. Moreover, certain magnetic configurations are known to be unstable, and they could produce some mixing of their own. We shall discuss these problems in the light of the latest developments.

A new analitycally approximated interior metric for a stationary compact perfect fluid withequation of state µ+(1–n)p = µ0 is presented. Also, it is concluded that an object of this kindcan be a source of Wahlquist's metric.

We review the main results of our previous works, in which we have investigated the development of the Kelvin-Helmholtz (KH) instability in the transitional regime from sub-magnetosonic to super-magnetosonic by varying the solar wind velocity, in conditions typical of those observed at the Earth’s magnetopause flanks. In super-magnetosonic regimes, we show that the vortices produced by the development of the KH instability act as an obstacle in the plasma flow and may generate quasi-perpendicular magnetosonic shock structures extending well outside the region of velocity shear.

Modeling of molecular emission from interstellar clouds requires the calculation of rate coefficients for excitation by collision with the most abundant species. Based on new highly correlated potential energy surfaces, rotational excitation of C2H and C2H− radicals in collision with He are investigated. C2H fine and hyperfine structure is taken into account. As already found for other systems, rate coefficients for the C2H− ion are larger by a factor up to 3 compared to the neutral species.

This paper gives an overview of the potential of and developments on Transition Edge Sensors for astronomical research from Space. This type of sensor is under development for imaging X-ray spectrometers as well as for very sensitive InfraRed and sub-mm imaging detectors. This paper describes developments in Europe for the International X-ray Observatory IXO (ESA, JAXA, NASA) and for the SAFARI instrument on the Japanese IR-mission SPICA. 
The micro-calorimeter array for the IXO-mission will have an imaging array of at least 1024 pixels with high quantum efficiency in the 0.1–10 keV energy range and an energy resolution as small as 2 eV for each detected photon. The SAFARI instrument requires three imaging arrays with an optical Noise Equivalent Power (NEP) as low as ≤ 5 × 10-19 W/√Hz with a total amount of 5940 pixels to read a Fourier Transform Spectrometer. The paper is written to be read together with the presentation given at the Astrophysics Detector Workshop 2008, Nice 17–20 November 2008, France.

The origin of ultra-high energy cosmic rays (UHECR) has been widely regarded as one ofthe major questions in the frontiers of particle astrophysics. Gamma ray bursts (GRB), themost violent explosions in the universe second only to the Big Bang, have been a popularcandidate site for UHECR productions. The recent IceCube report on the non-observation ofGRB induced neutrinos therefore attracts wide attention. This dilemma requires aresolution: either the assumption of GRB as UHECR accelerator is to be abandoned or theexpected GRB induced neutrino yield was wrong. It has been pointed out that IceCube hasoverestimated the neutrino flux at GRB site by a factor of ~5. In this paper we pointout that, in addition to the issue of neutrino production at source, the neutrinooscillation and the possible neutrino decay during their flight from GRB to Earth shouldfurther reduce the detectability of IceCube, which is most sensitive to the muon-neutrinoflavor as far as point-source identification is concerned. Specifically, neutrinooscillation will reduce the muon-neutrino flavor ratio from 2/3 per neutrino at GRB sourceto 1/3 on Earth, while neutrino decay, if exists and under the assumption of normalhierarchy of mass eigenstates, would result in a further reduction of muon-neutrino ratioto 1/8. With these in mind, we note that there have been efforts in recent years inpursuing other type of neutrino telescopes based on Askaryan effect, which can inprinciple observe and distinguish all three flavors with comparable sensitivities. Suchnew approach may therefore be complementary to IceCube in shedding more lights on thiscosmic accelerator question.

We have chosen the name of GYES, one of the mythological giants with one hundred arms,offspring of Gaia and Uranus, for our instrument study of a multifibre spectrograph forthe prime focus of the Canada-France-Hawaii Telescope. Such an instrument could provide anexcellent ground-based complement for the Gaia mission and a northern complement to theHERMES project on the AAT. The CFHT is well known for providing a stable prime focusenvironment, with a large field of view, which has hosted several imaging instruments, buthas never hosted a multifibre spectrograph. Building upon the experience gained at GÉPIwith FLAMES-Giraffe and X-Shooter, we are investigating the feasibility of a highmultiplex spectrograph (about 500 fibres) over a field of view one degree in diameter. Weare investigating an instrument with resolution in the range 15 000 to 30 000, whichshould provide accurate chemical abundances for stars down to 16th magnitude and radialvelocities, accurate to 1 km s-1 for fainter stars. The study is led byGÉPI-Observatoire de Paris with a contribution from Oxford for the study of thepositioner. The financing for the study comes from INSU CSAA and Observatoire de Paris.The conceptual study will be delivered to CFHT for review by October 1st 2010.

Irradiation by cosmic ions plays a relevant role in the “space weathering” of solid materials in the airless bodies (rocky and/or icy objects) in the Solar System. Here, I discuss about some of the effects that have been studied in “simulation” experiments with a view to their astrophysical relevance. In particular I review some experimental results obtained so far after irradiation of relevant materials, namely: sputtering, ion implantation, and chemical synthesis of molecular species different from the original ones. All of those effects are accomplished by changes in the optical properties of irradiated layers and then of the color of the surfaces of the airless bodies. Some specific examples of the application of the experimental results to the physics and chemistry of planetary surfaces are discussed as well.

Observations of the interstellar medium (ISM) reveal its fractalstructure over a large range of scales. The quantitative description shows that the ISM consists mainly of surfaces, so that the stellar UV-radiation can deeply penetrate intothe ISM and in consequence dominates its physical and chemical conditions. Thus, the bulk of the ISM can be identified as photon dominated regions (PDRs). A simple model with the proper fractal characteristics is that of an ensemble of spherical clumps with a power-law mass spectrum and a power-law mass-size relation. Hence, we model the FIR line emission of the molecular gasby the integrated emission of such an ensemble, calculating the emission of individual clumps with the KOSMA-τ PDR code. This clumpy PDR-model, with observationally constrained parameters, is fitted to the CO, [C i], and [O i] emission along the Galactic plane as observed by the FIRAS instrument abord the COBE satellite. The FIR line intensity distribution with Galactic longitude is reproduced within factors of about 2. The predicted [C ii] 158 μm line intensity and FIR continuum emission also coincide with the observations.

There is a strong connection between the formation of a disk galaxy and the properties of the interstellar medium (ISM). Theoretical work has typically either focused on the cosmological buildup of a galaxy with a relatively crude model for the gas physics, or examined local processes in the ISM and ignored the global evolution of the galaxy itself. Here, I briefly review what has been learned from both of these approaches, and what can be done to bridge the gap between them. I argue that cosmological simulations need to learn from observational and theoretical work on local ISM properties and adopt more sophisticated models for the processes that they cannot resolve. Since the ISM is still incompletely understood, there are a number of reasonable approaches for these “subgrid" models, and I will discuss the strengths and limitations of each.

The dust in protoplanetary disks is influenced by many different processes. Among others, heating processes are the most important ones: they change not only the physical and chemical properties of dust particles, but also their emission spectra. In order to compare observed infrared spectra of young stellar systems with laboratory data of hot (up to 655°C) circumstellar dust analogues, we investigate materials, which are important constituents of dust in protoplanetary disks. We calculated the optical constants by means of a simple Lorentzian oscillator fit and applied them to simulations of small-particle emission spectra in order to compare our results with real astronomical spectra of AGB-stars and protoplanetary disks.

The Antarctic plateau has superb astronomical seeing above aturbulent boundary layer. This layer has a thickness of between tensof metres and a few hundred metres, depending on the site. We aredeveloping a sonic radar, SNODAR, to measure the turbulence in theboundary layer from 10 to 50 m, and, in particular, to measurethe height of the boundary layer to an accuracy of 1 m.Commercial sonic radars typically have a lower limit of about 10 m, and have 10 m range bins. The results from SNODAR shouldallow a confident assessment of the height at which one must mount atelescope in order to realise the superb free atmosphere seeing fromthe Antarctic plateau, which has been measured at Dome C to be 0.27arcsecs on average, and better than 0.15 arcsecs for 25% of thetime.


I present a personal summary of the first ARENA conference on the prospects of building large astronomical infrastructures at the Concordia station in Antarctica, and my view on our progress to date in achieving this goal. Inparticular, I discuss the basic scientific, technical, and political conditions which I believe must be satisfied in order to develop a world-classinternational astronomical facility at Concordia.