In this review the present status of molecules in circumstellar envelopes of AGB stars is presented. Emphasis is put on the determination of abundances, and estimates of their uncertainties, from an observational point of view. Despite an impressive number of circumstellar species detected, about 60, there remains much work before general conclusions can be drawn. In particular, sophisticated radiative transfer modelling of circumstellar line emission must be done. This requires a detailed knowledge of the stellar and circumstellar properties, as well as basic molecular physics/chemistry data.

We present here the results of new XMM-Newton observations of the PSR B1259–63 system during the beginning of 2004, as the pulsar approaches the disc of the Be star. We combine these results with earlier X-ray data from BeppoSAX, XMM-Newton, and ASCA. The X-ray light curve looks similar to the radio light curve with a rapid increase in the flux around the time of the disc crossing. This supports a model in which the X-ray emission from the system is due to inverse Compton scattering of the pulsar wind relativistic particles with moderate Lorentz factor $\gamma \sim 10$–100 on the Be star soft photons.

We report on astrophysical aspects of fully innovative very wide–field X-ray telescopes with high sensitivity. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc.

The ESA observatory INTEGRAL (International Gamma-Ray Astrophysics Laboratory) is dedicated to fine imaging and spectroscopy in the energy range 15 keV to 10 Mev with concurrent X-ray (3-35 keV) and optical monitoring. It was launched on October 17, 2002 and has been succesfully operating ever since. Its two main instruments the spectrometer SPI – optimized for high resolution spectroscopy – and the imager IBIS – optimized for for high resolution imaging – are complemented by the X-ray monitor JEM-X and the optical monitor OMC. All the high energy instruments use coded mask techniques, allowing imaging in the gamma-ray range and combining wide fields of view with high spatial resolution. The presentation gives an overview of the unique properties of INTEGRAL.

Deep field observations are an essential tool to probe the cosmological evolution of galaxies. In this context, X-ray deep fields provide information about some of the most energetic cosmological objects: active galactic nuclei (AGN). Astronomers are interested in detecting sufficient numbers of AGN to probe the accretion history at high redshift. This talk gives an overview of the knowledge resulting from a highly complete soft X-ray selected sample collected with ROSAT, XMM–Newton and Chandra deep fields. The principal outcome based on X-ray luminosity functions and space density evolution studies is that low–luminosity AGN evolve in a dramatically different way from high–luminosity AGN: The most luminous quasars perform at significantly earlier cosmic times and are most numerous in a unit volume at cosmological redshift $z\sim2$. In contrast, low–luminosity AGN evolve later and their space density peaks at $z\sim 0.7$. This finding is also interpreted as an anti–hierarchical growth of supermassive black holes in the Universe. Comparing this with star formation rate history studies one concludes that supermassive black holes enter the cosmic stage before the bulk of the first stars. Therefore, first solutions of the so-called hen–egg problem are suggested. Finally, status developments and expectations of ongoing and future extended observations such as the XMM–COSMOS project are highlighted.

We present models for gamma-ray production in microquasars and we propose them as possible parent populations for different groups of EGRET unidentified sources. These models are developed for a variety of scenarios taking into account several possible combinations, i.e. black holes or neutron stars as the compact object, low mass or high mass stellar companions, as well as leptonic or hadronic gamma-ray production processes.

The role of high spectral and spatial resolution spectroscopy in understanding the evolution of the gaseous component of circumstellar accretion disks is described. Millimeter-wave emission lines from trace constituents such as CO, CN, HCO+, and HCN can be used to probe the kinematic and physico-chemical properties in the near-surface regions of disks beyond 50–100 AU, but, thanks to extensive depletion in the midplane, they are not a reliable proxy for the disk mass. For the special case of nearly edge-on circumstellar disks, the resulting ices can be directly observed through mid-infrared spectroscopy, using ground based facilities or spacecraft (cf. Najita, this volume). Emerging and planned millimeter-wave → THz arrays will possess sufficient sensitivity and resolution to probe much closer to the central star and to search for prebiotic compounds such as those detected in comets, meteorites and interplanetary dust particles.

While the physical characterization of near-Earth objects (NEOs) is progressing at a much slower rate than that of discovery, a substantial body of thermal-infrared data has been gathered over the past few years. A wide variety of taxonomic classes in the NEO population have now been sampled by means of thermal-infrared spectrophotometric observations. The resulting albedo information, together with the distribution of taxonomic types from spectroscopic investigations and the rapidly increasing catalog of orbits and absolute magnitudes derived from NEO search programs, such as LINEAR, facilitates more accurate estimates of the size distribution of the NEO population and the magnitude of the impact hazard. Despite our rapidly increasing knowledge of the NEO population, many questions and uncertainties remain, such as: How does the albedo distribution of NEOs compare with that of main-belt asteroids, and does space weathering play a role? How does the surface structure and regolith coverage of NEOs vary with size and taxonomic type? What fraction of NEOs are extinct comets? A property of particular interest is the surface thermal inertia of small asteroids, which is an indicator of the presence or lack of a thermally-insulating surface layer. Large asteroids can accumulate regolith, but can very small asteroids retain thermally-insulating collisional debris or at least a dust layer? Knowledge of thermal inertia is important for accurate calculations of the Yarkovsky effect, which can significantly influence the orbital evolution of potentially hazardous NEOs, and for the design of instruments for lander missions. Contrary to earlier expectations, evidence appears to be accumulating that even sub-kilometer asteroids often have a significant thermally-insulating surface layer. Recent results from thermal-infrared investigations of NEOs are reviewed and implications for the surface properties of small asteroids discussed.

I review here the current ideas regarding the origin, evolution, and physical nature of hot diffuse gas in normal, starburst, interacting and merging galaxies, using recent X-ray observations with XMM-Newton and Chandra. Many types of diffuse X-ray structures, including winds, bubbles, halos, chimneys and fountains, can be formed in galaxies, and can enrich the intergalactic medium with mass, energy and metals. This has profound implications as regards galactic formation and evolution, and the enrichment and evolution of galaxy groups and clusters.

The proliferation of X-ray astronomy missions over the last 10 years has had a major impact on our knowledge of Galactic X-ray binaries. More recently, Chandra and XMM-Newton have provided a dramatically improved census of extra-galactic X-ray binaries. In this talk I will provide an overview of the various populations and observational properties of X-ray binaries in our Galaxy, in an effort to “set the scene” for a comparison with their extra-galactic counterparts.

From October 1999 to the present Chandra has taken nearly monthly snap-shot observations of M31. The first 3 years of this dataset in combination with deeper but less frequent XMM observations has allowed the detection of 45 X-ray transients within M31. By analogy to our Galaxy, many of these transients are likely black hole candidates. We have indentified a few optical counterparts of these possible black holes via simultaneous HST imaging. The census allows a study of the endpoints of stellar evolution in our nearest neighbor galaxy. When stacked, the observations also allow a deep study of the M31 X-ray source population, which turns up a few surprises. The supermassive black hole in the center of M31 is the next nearest one after Sgr A*. Chandra and HST observations allow the detection of a weak X-ray source at the position of this SMBH. These observations provide some of the most secure and severe limitations on accretion in SMBH.

We present gamma–ray and X-ray analysis of GRB040223 observed by INTEGRAL and XMM-Newton. GRB 040223 has a peak flux of $(1.6 \pm 0.1) \times 10^{-8}$ ergs cm$^{-2}$ s$^{-1}$, a fluence of (4.4 $\pm$ 0.4) $\times$ 10$^{-7}$ ergs cm$^{-2}$ and a steep photon power law index of −2.3 $\pm$ 0.2, in the energy range 20–200 keV. The steep spectrum implies that it is an X-ray rich GRB with emission up to 200 keV and $E_{\rm peak}<20$ keV. The luminosity-lag relationship was used to obtain a redshift $z=0.10^{+0.04}_{-0.02}$. The isotropic energy radiated in $\gamma$-rays and X-ray luminosity after 10 hours are both orders of magnitude less than classical GRBs.

Several new multiply deuterated species have been detected over the past three years, including ND3 (van der Tak et al. 2002; Lis et al. 2002), CHD2OH, CD3OH (Parise et al. 2002, 2004), D2S (Vastel et al. 2003), HD2+ (Vastel et al. 2004) and D2CS (Marcelino et al. 2005). In addition, mono-deuterated species have been observed with abundances >10% of their un-deuterated analogues (e.g. CH2DOH observed by Parise et al. 2002; NH2D observed by Saito et al. 2000 and Hatchell 2003). These are remarkable results, given that the underlying abundance of deuterium in the local interstellar medium (ISM) is ∼10−5 times lower than that of hydrogen (Linsky 1998; Sonneborn et al. 2000).

Such large enhancements in the abundances of deuterium-bearing molecules can either be due to gas-phase or to grain-surface fractionation. Grain-surface reactions are undoubtedly important in producing saturated species such as methanol, water, ammonia, and hydrogen sulphide. Water ice is observed to be abundant and ubiquitous throughout the ISM, and enhanced abundances of gas-phase NH3, CH3OH, H2CO and H2S (among others) are observed in warmer regions around protostars where grain mantles have evaporated.

Recent observational and theoretical evidence suggests that the deuterium fractionation in star-forming regions is set by gas-phase and grain-surface reactions during the cold, dense pre-protostellar phase. For species which form on grain surfaces via H atom addition to CO, N, O and S, the deuterium fractionation on grains comes from the relative amounts of atomic D and H which are accreting from the gas. The observations of deuterated methanol and D2S require that the gas-phase atomic D/H ratio at the time the molecules formed was ≥ 0.1.

This paper presents results from chemical models of the prestellar core phase of star formation, showing how this high atomic D/H ratio can be produced, and discusses how models can also be used to look at deuterium fractionation in the protostellar stages of star formation.

We report on an XMM-Newton observation of the supernova remnant (SNR) DEM L241 in the Large Magellanic Cloud. In the soft band image, the emission shows an elongated structure, like a killifish (Head and Tail), with a central point source, named as XMMU J053559.3–673509 (Eye). The Eye's spectrum is well reproduced with a power-law model. The source has neither significant coherent pulsations nor time variabilities. Its luminosity and spectrum remind us that the source might be a pulsar and/or pulsar wind nebula in DEM L241. The spectra of Head and Tail are well reproduced by a non-equilibrium ionization plasma model with over-abundant Ne and under-abundant Fe, suggesting that the progenitor of DEM L241 is a very massive star.

We present the first results of our X-ray monitoring campaign using the X-ray satellites XMM-Newton and Chandra on the 1.7 square degree region centered on Sgr A*. The purpose of this campaign is to monitor the X-ray behavior of X-ray sources (both persistent and transient ones) which are too faint to be detected by monitoring instruments aboard other satellites currently in orbit (e.g., RXTE, Integral, Swift). Our first observations were obtained on June 5, 2005, using the HRC-I detector aboard Chandra. Here we briefly discuss our results on the very faint X-ray transients we detected during these observations. We detected new outbursts (with peak luminosities close to $10^{36}$ erg s$^{-1}$) of the two very faint transients GRS 1741.9–2853 and XMM J174457-2850.3, as well as a potential new very faint X-ray transient with an outburst luminosity of a few times $10^{34}$ erg s$^{-1}$.

Mathematical modelling of meteoroid streams formation and evolution is a very fruitfull method for obtaining not only cosmogonical knowledges, but information about the stream up-to-date structure as well. In this review we consider advances of the method, and applications to meteoroid streams of different schemes of formation. We also discuss the part played by observations, and feedback between models and observations. Attention is also drawn to some unresolved problems and promising areas of application.

Non-gravitational perturbations, regardless being many orders of magnitude weaker than gravity, hold keys to fully understand the evolution of small Solar System bodies. This is because individual bodies, or their entire groups, manifest traces of a long-term accumulated changes by these effects.

For meteoroids and small asteroids in the 10 cm–10 km size range, the principal non-gravitational force and torque arise from an anisotropic thermal emission of the absorbed solar radiation. Related perturbations of the orbital and rotational motion are called the Yarkovsky and YORP effects.

We review the most important Yarkovsky- and YORP-driven processes, in the Main Asteroid Belt. These include: steady and size-dependent semimajor axis drift, secular changes of rotational period and obliquity, efficient transport towards low-order resonances, interaction with weaker higher-order resonances, captures in secular and spin-orbit resonances.

Many independent observations can be naturally interpreted in the framework of Yarkov-sky/YORP models, like cosmic ray exposure ages of meteorites, current population and size-distribution of near-Earth objects, the existence of unstable resonant asteroids or the structure of asteroid families.

The branching ratios of the different reaction pathways and the overall rate of the dissociative recombination of CD$_{3}$OD$_{2}^{+}$ were measured at the CRYRING storage ring located at the Manne Siegbahn Laboratory in Stockholm, Sweden. A preliminary analysis of the data yielded that formation of methanol accounts for only 6 $\pm$ 2% of the total reaction rate. Largely, dissociative recombination of CD$_{3}$OD$_{2}^{+}$ involves fragmentation of the C–O bond, the major process being the three-body break-up forming CD$_{3}$, OD and D (branching ratio 0.59). A non-negligible formation of interstellar methanol by the previously proposed mechanism is therefore very unlikely.

The classical trajectory methodology for studying scattering of ions, atoms, or molecules from ice surfaces, and photodissociation of water at or in the surface of ice, is presented. The forces between the collider and the water molecules, or between the fragments of a dissociating molecule and the surrounding water molecules, are based on pair potentials taken either from ab initio calculations or derived empirically. Dynamical observables like sticking probabilities and kinetic energy distributions of desorbing photo-fragments are computed by solving Newton's equations of motion, starting from representative initial conditions. Four studies with relevance to astrochemistry are considered: the sticking of H atoms to ice Ih, the sticking of CO to ice Ih and ice Ia, the sticking of protons to ice Ih, and the photodissociation of water in ice Ih and ice Ia, also with a view to the subsequent chemistry of the H-and OH-products with co-adsorbed molecules. Where possible, the theoretical results are compared with experiments.

The present status of our knowledge of the composition of cometary nuclei is reviewed and compared with what we know on the composition of other Solar System minor bodies – interplanetary dust, meteorites, asteroids, trans-Neptunian objects. The current methods of investigations – by both in situ analysis and remote sensing – are described. Comets are active objects pouring their internal material to form a dusty atmosphere which can be investigated by remote sensing. This is not the case for minor planets and trans-Neptunian objects for which only the outer surface is accessible. Collected interplanetary dust particles and meteorites can be analysed at leisure in terrestrial laboratories, but we do not know for certain which are their parent bodies.

Considerable progresses have been made from spectroscopic observations of active comets, mainly at infrared and radio wavelengths. We probably know now most of the main components of cometary ices, but we still have a very partial view of the minor ones. The elemental composition of cometary dust particles is known from in situ investigations, but their chemical nature is only known for species like silicates which have observable spectral features. A crucial component, still ill-characterized, is the (semi-)refractory organic material of high molecular mass present in grains. This component is possibly responsible for distributed sources of molecules in the coma. A large diversity of composition from comet to comet is observed, so that no “typical comet” can be defined. No clear correlation between the composition and the region of formation of the comets and their subsequent dynamical history can yet be established.