The population of HMXBs in the MCs and the Galaxy is investigated. The SMC has an over-abundant population of HMXBs. This provides the clues that the SMC should be more active in massive star formation. The pulse periods in the SMC are slightly shorter than those in the Galaxy, implying that most of the pulsars in Be/X-ray binaries are not spin-up.

The direct detection of light emitted or reflected by extrasolar planets will soon allow studies of the physical properties of their surfaces and atmospheres. This article gives an overview of the scientific perspectives and the techniques that are currently being developed for observations of gas giants and terrestrial planets from the ground and in space.

Before the discovery of the first member of the Kuiper belt in 1992, the trans-Neptunian population was supposed to lie on a flat disk and each member would follow a barely eccentric orbit. While less conventional orbits for the trans-Neptunian objects were being discovered, our understanding of its orbital structure and origin was continually changed. A basic classification of the trans-Neptunian population as to their orbits identifies a classical low inclination Kuiper belt population, a resonant population, a high inclination Kuiper belt population, a scattered population and an extended population. Several mechanisms have been proposed to explain the orbital architecture of the Kuiper belt population. Presently, the most plausible scenarios are unequivocally related with the primordial planetary migration induced by a planetesimal disk. Low inclination orbits in the Kuiper belt may have been moderately pushed out from a dynamically cold primordial disk by the resonance sweeping mechanism. The origin of high inclination objects in the classical Kuiper belt is however to be found in a primordial Neptune scattered population, through a perihelion increasing mechanism based on secular resonances. Another push-out mechanism based on the sweeping of the 1:2 resonance with Neptune has also been invoked to explain the low inclination orbits in the classical Kuiper belt. Assuming these last two mechanisms, Kuiper belt objects do not need to have been formed in situ. This kind of formation process would demand a quite large original mass in the Kuiper belt region, which would have brought Neptune beyond its present position at 30 AU. Thus with the exception of the low inclination classical Kuiper belt objects and a few resonant ones, all other trans-Neptunian objects are present or past scattered objects. This notion also includes the case for Sedna, so far the only certain member of the extended population. In its most plausible formation scenario, it was a primordial scattered object by Neptune whose perihelion was increased by the close passage of a star.

It is shown that there is no underlying basic theory which will lead to the idea that the lightest isotopes were produced in an early universe. Everything depends on the choice of the initial ratio of the energy density of photons to baryons that is chosen (originally by Gamow and his colleagues). There is a clear alternative for the origin of the light isotopes. This is that they were generated by hydrogen burning in stars which produces the helium directly while $^{2}D$ and $^{7}Li$ are produced by flare activity in stellar atmospheres. All of this activity takes place in the centers of active galaxies where matter is being created in a cyclic (quasi-steady) state universe.

We discuss issues concerning the physical nature of intervening MgII quasar absorption systems in light of results from our recent surveys using SDSS EDR QSO spectra and data obtained at the MMT. These surveys indicate an excess of weak ($W_0^{\lambda2796} \lesssim 0.3$Å) systems relative to the exponential $\partial N/\partial W_0$ distribution of stronger systems. The incidence of intermediate-strength lines shows remarkably little evolution with redshift, thereby constraining models for the nature of the clouds comprising these absorbers. The total distribution does evolve, with the incidence decreasing with decreasing redshift in a $W_0^{\lambda2796}$-dependent rate (the strongest systems evolve the fastest). This suggests that multiple populations that evolve at different rates contribute to the incidence in a $W_0^{\lambda2796}$-dependent manner. We also present two images of fields containing unprecedented “ultra-strong” ($W_0^{\lambda2796} \ge 4.0$Å) MgII absorbers.

Superjupiters are much brigther when they are young and still contracting, and the contrast with the harboring stars is significantly more favorable for their detection. Within the JOVIAN (Jupiter-like Objects in the Visible and the Infrared: Astrophysical Nature) project, a search has been performed for superjupiters around nearby young stars using 4 m class telescopes. Here we summarize the results and present prospects for a future search around young and also relatively older nearby stars with the 10 m Gran Telescopio Canarias and the mid-infrared camera CanariCam.

The paper focuses on collisional excitation rates of molecules by He and H2 relevant to the interstellar medium. It discusses currently available data, presents very recent work and outlines new work being carried out by various teams.

Recent results on the kinematics of the Draco and Ursa Minor dwarf spheroidals are reviewed.

The WG has conferred via email on the topics of providing a precession theory dynamically consistent with the IAU 2000A nutation theory and updating the expressions defining the ecliptic. The consensus of the WG is to recommend:

(a) The terms lunisolar precession and planetary precession be replaced by precession of the equator and precession of the ecliptic, respectively.

(b) The IAU adopt the P03 precession theory, of Capitaine et al (2003a, A& A 412, 567–586) for the precession of the equator (Eqs. 37) and the precession of the ecliptic (Eqs. 38); the same paper provides the polynomial developments for the P03 primary angles and a number of derived quantities for use in both the equinox based and celestial intermediate origin based paradigms.

(c) The choice of precession parameters be left to the user.

(d) The recommended polynomial coefficients for a number of precession angles are given in Table 1 of the WG report, including the P03 expressions set out in Tables 3–;5 of Capitaine et al (2005, A& A 432, 355–;367), and those of the alternative Fukushima (2003, AJ 126, 494–;534) parameterization; the corresponding matrix representations are given in equations 1, 6, 11, and 22 of the WG report.

(e) The ecliptic pole should be explicitly defined by the mean orbital angular momentum vector of the Earth-Moon barycenter in an inertial reference frame, and this definition should be explicitly stated to avoid confusion with older definitions. The formal WG report will be submitted, shortly to Celest. Mech. for publication and their recommendations will be submitted at the next General Assembly for adoption by the IAU.

We found that in regions of high mass star formation the CS emission correlates well with the dust continuum emission and is therefore a good tracer of the total mass while the N$_2$H$^+$ distribution is frequently very different. This is opposite to their typical behavior in low-mass cores. The behavior of other high density tracers varies from source to source but most of them are closer to CS. Radial density profiles in massive cores are fitted by power laws with indices about −1.6, as derived from the dust continuum emission. The radial temperature dependence on intermediate scales is close to the theoretically expected one for a centrally heated optically thin cloud. The velocity dispersion either remains constant or decreases from the core center to the edge. Several cores including those without known embedded IR sources show signs of infall motions. They can represent the earliest phases of massive protostars. There are implicit arguments in favor of small-scale clumpiness in the cores.

Magnetic fields may be observed via the Zeeman effect, linear polarization of dust emission, and linear polarization of spectral-line emission. Useful parameters that can be inferred from observations are the mass-to-flux ratio $M/\Phi$ and the scaling of field strength with density. The former tells us whether magnetic fields exert sufficient pressure to provide support against gravitational contraction; the latter tells whether or not magnetic fields are sufficiently strong to determine the nature (spherical or disk geometry) of the contraction. Examples of massive star formation regions for which detailed observations have been made of magnetic field strengths and morphologies include DR21OH, OMC1, and S106; observational results for these regions and relevant results for the diffuse ISM and masers will be reviewed. Results are that the strength of interstellar magnetic fields remains invariant at $B {\sim} 6\mu$G between 0.1 cm$^{-3} < n(H) < 10^3$ cm$^{-3}$, but increases as $B \propto \rho^{0.4-0.5}$ for $10^3$ cm$^{-3} < n(H_2) < 10^{8}$ cm$^{-3}$. Moreover, $M/\Phi$ is significantly subcritical (strong $B$ with respect to gravity) in diffuse H I clouds that are not self-gravitating, but becomes approximately critical in high-density molecular cloud cores. This suggests that GMCs form primarily by accumulation of matter along magnetic field lines, a process that will increase density but not magnetic field strength. How clumps in GMCs evolve will then depend critically on the $M/\Phi$ ratio in each clump.

Understanding the energy and matter content of the Universe and its evolution are key goals for the international astronomical community and all extremely large telescope projects. ELTs will bring a wide range of tools to bear on questions relating to the nature of dark energy and the formation and early evolution of galaxies. Natural seeing and ground-layer corrected instruments on ELTs will quantify the assembly of galaxies at modest redshifts, while near-IR diffraction-limited instruments will probe the internal structure of early galaxies and the epoch of first light and reionization.

We present here a software for simulations of observations made with an Integral Field Spectrograph attached to an extreme adaptive optics system, with the main goal of simulating direct detection of extrasolar planets and to test the capabilities in detecting planets of an instrument based on IFS on large telescopes. This code, written for IDL, has been conceived within the CHEOPS project, a second generation “Planet Finder” instrument for ESO's VLT; but it has been extended to the case of various ELTs. Here we describe in detail the procedure adopted in order to simulate realistic values of speckle noise, Adaptive Optics corrections, specific instrumental features and the efficiency of a Simultaneous Differential Imaging technique to increase the signal of the planet.

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.

We consider the feasibility of detecting neutron star companions to High Mass X-ray Binaries (HMXBs) using astrometric techniques, specifically for accuracies expected for the upcoming Gaia satellite. The direct determination of orbital parameters of HMXBs will increase the census of measured neutron star masses.

Within the near-Earth object population, one finds asteroids, comets, and meteorites thereby placing the NEO population at the center of the ACM conference. The longstanding gulf between the spectral properties of S-type asteroids and ordinary chondrite meteorites appears to be bridged, where the observational data are consistent with a space weathering type process. As much as 30% of the entire NEO population may reside in orbits having a Jovian Tisserand parameter <30, and among these roughly half are observed to have comet-like physical properties in terms of their albedos and spectra (taxonomy). Thus 15±5% of the entire NEO population may be comprised by extinct or dormant comets.

With the COLLISA foil experiment onboard the Mir space station we have collected samples of interstellar helium, which have been returned to the Earth and investigated by mass spectrometric analysis. Recently, we have been able to reduce the experimental uncertainties as given earlier (Salerno et al. 2003). Our improved estimate of the helium isotopic ratio in the local interstellar medium is now ($^3$He/$^4$He)$_{LISM}$=(1.62 $\pm$ 0.29)$\,{\times}\,$10$^{-4}$ (Busemann et al. 2005).

We present the results of optical stellar rotation curves of 16 dwarf elliptical galaxies in the Virgo Cluster. Approximately half of this sample have significant velocity gradients along their optical major axis, with typical rotation amplitudes of 20—30 km s$^{-1}$. Evidence for a relationship between the rotation amplitude and galaxy luminosity is found and agrees well with the Tully-Fisher relation. The similarity in the scaling relations of dIs and dEs implies that it is unlikely that dEs evolve from significantly more luminous galaxies. These observations reaffirm the possibility that some cluster dwarf elliptical galaxies may be formed when the neutral gaseous medium is stripped from dwarf irregular galaxies in the cluster environment.

We present results from two projects in which we have used the HI 21cm emission line as a tracer of gas-rich galaxy populations in the vicinity of Lyman-$\alpha$ absorbers. In the first case, we examine the HI environment of SBS 1543+593, the nearest damped Lyman-$\alpha$ absorber. We use a VLA map of the region around this LSB galaxy which itself shows an extended HI disk to identify 3 gas-rich neighbours within 185 kpc. While it is not clear whether we should expect local damped Lyman-$\alpha$ systems to reside in such gas-rich regions, we would expect this kind of environment to be more prevalent at higher redshifts where less of the gas is in the dense inner regions of galaxies or has been consumed by star formation. This local galaxy is the only system in which we can study the gaseous environment in this kind of detail. In the second case, we examine the HI environment surrounding 16 Lyman-$\alpha$ forest absorbers along 4 QSO sight-lines. We do not detect any gas-rich galaxies at the absorber positions indicating that, at least down to our sensitivity limits, these absorption lines do not seem to be associated with galaxy halos. For half of the Lyman-$\alpha$ absorption systems there is a galaxy within 500 kpc, but for the other half there is not. In two cases there is no galaxy within 2 Mpc of the Lyman-$\alpha$ absorption systems indicating that absorbers do, in some cases, reside in voids.

Division II of the IAU provides a forum for astronomers studying a wide range of phenomena related to the structure, radiation and activity of the Sun, and its interaction with the Earth and the rest of the solar system. Division II encompasses three Commissions, 10, 12 and 49, and four working groups. During the last triennia the activities of the division involved some reorganization of the division and its working groups, developing new procedures for election of division and commission officers, promoting annual meetings from within the division and evaluating all the proposed meetings, evaluating the division's representatives for the IAU to international scientific organizations, and participating in general IAU business.