We ask if Earth-like planets (terrestrial mass and habitable-zone orbit) can be detected in multi-planet systems, using astrometric and radial velocity observations. We report here the preliminary results of double-blind calculations designed to answer this question.


The infrared (IR) spectra of many galactic and extragalactic objects are dominated byemission features at 3.3, 6.2, 7.7, 8.6 and 11.2 μm, generally attributedto the IR fluorescence of Polycyclic Aromatic Hydrocarbon molecules (PAHs). These PAHbands have been found in a wide variety of environments throughout theUniverse and containup to 10% of the total power output of star-forming galaxies.

Ground-based telescopes, the Infrared Space Observatory (ISO) and the Spitzer SpaceTelescope revealed a plethora of weaker PAH bands and provided extensive evidence forsignificant variability in the PAH spectrum from source to source and spatially withinsources. Here we review the spectral characteristics of astronomical PAHs, theirdependence on the local physical conditions and the implications for the physical andchemical characteristics of the carriers.

We find that deviation from the virial equilibrium of the Abell Cluster A586 yields evidence of the interaction between dark matter and dark energy. We argue that this interaction might imply a violation of the Equivalence Principle. These evidences are found in the context of two different models of dark energy-dark matter interaction.

During the five years of the mission, the Gaia spectrograph, the Radial VelocitySpectrometer (RVS) will repeatedly survey the celestial sphere down to magnitudeV ~ 17–18. This talk presents: (i) the system which is currently developed withinthe Gaia Data Processing and Analysis Consortium (DPAC) to reduce and calibrate thespectra and to derive the radial and rotational velocities, (ii) the RVS expectedperformances and (iii) scientific returns.

This review describes five categories of the reactions of polycyclic aromatichydrocarbons, including photochemistry, electron attachment/detachment, recombinationprocesses, radical reactions, and ion-neutral chemistry. For each class of reaction, anoverview of the studies and their general results are presented, as well as references tothe literature. The thermochemistry of PAHs and relevant species is described, includingbond dissociation energies, ionization energies, electron affinities, basicities,acidities, and the interrelationships of these quantities. Modeling of the chemistry ofPAHs and their ions is discussed for both diffuse and dark clouds. The role of PAH cationsin the catalytic formation of molecular hydrogen is considered. Finally, this reviewconcludes with a discussion of current challenges in the chemical characterization ofPAHs, and a perspective for future studies.

The new astrochemistry experiment PIRENEA is presented.The set-up was designed to approach the physical conditionsthat prevail in the interstellar medium. It enables to performoriginal studies in particular when large molecules andnano-sized particles are involved. The experiment is nowoperational for science.

Over the past forty years, investigations of radio recombinationlines have become an effective way of studying the interstellarmedium. The electron temperatures, densities, emission measures,kinematics parameters, elemental abundances and other physicalcharacteristics of emission processes in planetary nebulae,distributed ionized gas, stellar winds, the partially-ionizedinterstellar medium and external galaxies are determined with thelines of hydrogen, helium, carbon, etc. This astrophysicalphenomenon is unique because of the large (>1000) number ofpossible quantum transitions and because of the wide observablefrequency range (from ~150 GHz to ~10 MHz). In thisshort review the main results from recombination radio lineinvestigations are discussed. Special attention is given to theareas which have been given least attention in the literature suchas the radio recombination lines of very excited carbon atoms atthe extremely low-frequency (v < 30 MHz) end of the decameterwavelength range. This is important to stress in the 70-th jubileeof radio astronomy because cosmic radio emission was discovered byKarl Jansky at decameter wavelengths. Investigations of theextremely low-frequency radio recombination lines are also veryinteresting for the prospective LOFAR system.

In the past years a wealth of observations has unraveled the structural properties of the Dark and Luminous mass distribution in spirals. These have pointed out to an intriguing scenario not easily explained by present theories of galaxy formation. The investigation of individual and coadded objects has shown that the spiral rotation curves follow, from their centers out to their virial radii, a Universal profile (URC) that arises from the tuned combination of a stellar disk and of a dark halo. The importance of the latter component decreases with galaxy mass. Individual objects, on the other hand, have clearly revealed that the dark halos encompassing the luminous discs have a constant density core. This resulting observational scenario poses important challenges to presently favored theoretical ΛCDM Cosmology.

The Pioneer 10/11 spacecraft yielded the most precise navigation in deepspace to date. However, their radio-metric tracking data has consistentlyindicated the presence of a small, anomalous, Doppler frequency drift. Thedrift is a blue-shift, uniformly changing with a rate of ~6 × 10-9 Hz/s and can be interpreted as a constant sunward acceleration ofeach particular spacecraft of aP = (8.74 ± 1.33) × 10-10 m/s2. The nature of this anomaly remains unexplained. Here wesummarize our current knowledge of the discovered effect and review some ofthe mechanisms proposed for its explanation. Currently we are preparing forthe analysis of the entire set of the available Pioneer 10/11 Doppler datawhich may shed a new light on the origin of the anomaly. We present apreliminary assessment of such an intriguing possibility.


Polycyclic Aromatic Hydrocarbons (PAHs) are the most likely carriers proposed to account for the Aromatic Infrared Bands observed in emission between 3.3 and 12.7 μm, fulfilling both the chemical (presence of CC and CH aromatic bonds) and excitation constraints. We explain here how the emission spectrum of such species in astronomical environments can be modelled, to obtain for each infrared band both its intensity and its detailed profile.
The PAH model suffers from the lack of identification of individual species. Two strategies are described here that are currently being used to progress in this identification process. The first idea is that features in the far IR are much more specific to the exact molecular identity. Therefore their search with the coming Herschel Space Observatory will provide an unambiguous way to identify these molecules through their IR emission. Second, a reflection on where interstellar PAHs come from and how they evolve due to environmental conditions (UV irradiation, gas and dust interactions) is also necessary to get more insights into the nature of interstellar PAH candidates. In particular, recent studies have emphasized a chemical link between PAHs and very small grains in photodissociation regions.
Finally, we illustrate in this paper how progress in this field can only be attained by a synergy between astronomical observations, fundamental studies, both theoretical and experimental, and models.

Theoretical models of the equation of state (EOS)of neutron-star matter (starting with the crustand ending at the densest region of the stellar core) are reviewed. Apart froma broad set of baryonic EOSs, strange quark matter, and even more exotic (abnormaland Q-matter) EOSs are considered. Results of calculations of Mmaxfor non-rotating neutron stars and exotic compact stars are reviewed, withparticular emphasis on the dependence on the dense-matter EOS. Rapid rotationincreases Mmax, and this effect is studied for both neutron stars and exoticstars. Theoretical results are then confronted with measurements of masses of neutronstars in binaries, and the consequences of such a confrontation and their possible impacton the theory of dense matter are discussed.

The prospects of using extreme relativistic laser-matter interactions for laboratoryastrophysics are discussed. Laser-driven process simulation of matterdynamics at ultra-high energy density is proposed for the studies of astrophysical compactobjects and the early universe.

We review the significant role played by red supergiants (RSGs) in stellar populations,and some challenges and questions they raise for theoretical stellar evolution. We presenthow metallicity and rotation modify the way stars go to the red part of theHertzsprung-Russell diagram or come back from it, and how RSGs might keep a trace of theirmain-sequence evolution. We compare theoretical population ratios with observed ones.

Herschel opens the possibility to detect the low-frequency vibrationalbands of individual polycyclic aromatic hydrocarbon (PAH) molecules and therefore toprogress in our understanding of the nature of these species and the properties of theenvironments from which they emit. However, unless one individual molecule dominates thePAH family, this detection will not be straightforward and it is necessary to optimise theobservational search with an educated guess of the band profiles and intensities. Sucheducated guess can be obtained from models that include a detailed description of themolecular properties (anharmonicity, rotation...) in the modelling of the cooling cascadeof the emitting species. First results are expected soon from the observation of the OrionBar as part of the HEXOS Herschel key program.

The status of kinematic observations in Local Group dwarf spheroidalgalaxies (dSphs) is reviewed. Various approaches to the dynamicalmodelling of these data are discussed and some general features ofdSph dark matter haloes based on simple mass models are presented.

After a brief introduction into the asteroseismic modelling of stars, we provide a compilation of the current seismic estimates of the core overshooting parameter and of the rotational frequency of single and binary massive stars. These important stellar parameters have meanwhile become available for eleven OB-type stars, among which three spectroscopic pulsating binaries and one magnetic pulsator. We highlight the potential of ongoing and future analyses of eclipsing binary pulsators as essential laboraties to test stellar structure and evolution models of single and binary stars.

The IR emission cascade from the pyrene cation due to a broad band optical excitation issimulated using kinetic Monte Carlo. Anharmonicities of the ground electronic statepotential energy surface are taken into account in the transition energies, themicrocanonical densities of states, and the rate of hydrogen loss through variousstatistical theories. The emission spectral features of the “3.3”, “6.2” and “11.2”μm bands are computed for different blackbody temperatures.

We present a new multi-fluid, grid-based magnetohydrodynamics (MHD) code PIERNIK, which is based on theRelaxing Total Variation Diminishing (RTVD) scheme. The original scheme has been extended by an addition ofdynamically independent, but interacting fluids: dust and a diffusive cosmic ray (CR)gas, described within the fluid approximation, with an option to add otherfluids in an easy way. The code has been equipped with shearing-box boundaryconditions, a selfgravity module, an Ohmic resistivity module, as well as otherfacilities which are useful in astrophysical fluid-dynamical simulations. Thecode is parallelized by means of an MPI library. In this paper we brieflyintroduce the basic elements of the RTVD MHD algorithm, following Trac & Pen (2003) and Pen et al.  (2003), and then focus on a conservativeimplementation of the shearing-box model, constructed with the aid of Masset's (2000) method. We present the results of a test example of the formation of a gravitationally bound object (a planet) in a self-gravitating and differentially rotating fluid.

Binarity is often invoked to explain peculiarities that can not be explained by the standard theory of stellar evolution. Detecting orbital motion via the Doppler effect is the best method to test binarity when direct imaging is not possible. However, when the orbital period exceeds length of a typical observing run, monitoring often becomes problematic. Placing a high-throughput spectrograph on a small semi-robotic telescope allowed us to carry out a radial velocity survey of various types of peculiar evolved stars. In this review we highlight some findings after the first four years of observations. Thus, we detect eccentric binaries among hot subdwarfs, barium, S stars, and post-AGB stars with disks, which are not predicted by the standard binary interaction theory. In disk objects, in addition, we find signs of the on-going mass transfer to the companion, and an intriguing line splitting, which we attribute to the scattered light of the primary.

Stellar evolution theory has been extraordinarily successful at explaining the different phases under which stars form, evolve and die. While the strongest constraints have traditionally come from binary stars, the advent of asteroseismology is bringing unique measures in well-characterised stars. For stellar populations in general, however, only photometric measures are usually available, and the comparison with the predictions of stellar evolution theory have mostly been qualitative. For instance, the geometrical shapes of isochrones have been used to infer ages of coeval populations, but without any proper statistical basis. In this chapter we provide a pedagogical review on a Bayesian formalism to make quantitative inferences on the properties of single, binary and small ensembles of stars, including unresolved populations. As an example, we show how stellar evolution theory can be used in a rigorous way as a prior information to measure the ages of stars between the Zero Age Main Sequence and the Helium flash, and their uncertainties, using photometric data only.