We discuss differences and similarities between jets powered by super-massive black holes in quasars and by stellar-mass black holes in microquasars. The comparison is based on multi-wavelength radio-to-infrared observations of the two active galactic nuclei 3C 273 and 3C 279, as well as the two galactic binaries GRS 1915+105 and Cyg X-3. The physical properties of the jet are derived by fitting the parameters of a shock-in-jet model simultaneously to all available observations. We show that the variable jet emission of galactic sources is, at least during some epochs, very similar to that of extragalactic jets. As for quasars, their observed variability pattern can be well reproduced by the emission of a series of self-similar shock waves propagating down the jet and producing synchrotron outbursts. This suggests that the physical properties of relativistic jets is independent of the mass of the black hole.

We calculate evolution, collapse, explosion, and nucleosynthesis of Population III very massive stars with 500 M⊙ and 1000 M⊙. It was found that both 500 M⊙ and 1000 M⊙ models enter the region of pair-instability but continue to undergo core collapse to black holes. For moderately aspherical explosions, the patterns of nucleosynthesis match the observational data of intergalactic and intercluster medium and hot gases in M82, better than models involving hypernovae and pair instability supernovae.

Our results suggest that explosions of Population III core-collapse very massive stars contribute significantly to the chemical evolution of gases in clusters of galaxies. The final black hole masses are about 500 M⊙ for our most massive 1000 M⊙ models. This result may support the view that Population III very massive stars are responsible for the origin of intermediate mass black holes which were recently reported to be discovered.

Accurate observational data are available for the eclipsing double-lined spectroscopic binary system RS Cha, composed of two stars in the pre-main sequence stage of evolution: masses, radii, luminosities and effective temperatures of each component and metallicity of the system. This allows to build pre-main sequence stellar models representing the components of RS Cha and to constrain them in terms of physical ingredients, initial chemical composition and age.

We present stellar models we have calculated using the CESAM stellar evolution code for different sets of physical inputs (opacities, nuclear reaction rates, etc.) and different initial parameters (global metallicity, helium abundance, individual abundances of heavy elements). We discuss their ability to reproduce the observational constraints simultaneously for the two components. We focus on the impact on the models of the chemical mixture adopted and we propose a calibration for the RS Cha system providing an estimate of its age and initial helium abundance.

Observed properties of spectroscopically confirmed galaxies at z≫5 and z≫6 based on selection from deep, multi-wavelength wide-field samples provide a picture of the current status of the properties of high-redshift galaxies and their evolution to yet higher redshifts.

In the current presentation, we use results of deep, wide-field spectroscopy with the multi-object Deimos spectrograph on Keck in combination with deep, wide-field multi-color imaging studies using the SuprimeCam CCD camera of Subaru for a number of fields, to evaluate the luminosity function of high-redshift galaxies and its evolution at z>6. High-redshift candidates are selected using both narrow-band Lyman alpha emission and broad-band colors with a high success-rate from a number of SuprimeCam (0.5 degree FOV) fields.

Luminosity functions and Lymanα emission line profiles and equivalent widths appear similar between samples at z≃5.7 and z≃6.5, and the galaxy distribution is structured both spatially and in redshift. A large amount of cosmic variance is seen in the distribution of z≫6 galaxies from field to field.

The observed properties are discussed in relationship to their impact on strategies for complementary optical surveys of high-redshift galaxies, and in relationship to surveys at very different wavelengths (X-ray, far-infrared, and submillimeter) that cover the same regions.

A near-infrared survey of the Magellanic Clouds has been carried out with IRSF/SIRIUS. As a part of the results, we present a study of triggered star formation in N11 in the LMC.

Red-sequence galaxies are known to obey well-defined scaling relations, such as the Fundamental Plane and the colour-magnitude relation, yet their star formation histories, which in part drive these relations, remain poorly understood. In this contribution, we summarize recent results from the NOAO Fundamental Plane Survey (NFPS). These results appear in more detail in Smith et al. (2006) and Nelan et al. (2005).

We present a multi-wavelength (NIR to radio) and multi-scale (1 AU to 10 pc) study of the S255–S257 complex of young high-mass (proto)stars. The complex consists of two evolved HII regions and a molecular gas filament in which new generations of high mass stars form. Four distinct regions are identified within this dusty filament: a young NIR/optical source cluster, a massive protostar binary, a (sub)millimetre continuum and molecular clump in global collapse and a reservoir of cold gas. Interestingly, the massive binary protostellar system is detected through methanol maser and mid-IR emission at the interface between the NIR cluster and the cold gas filament. The collapsing clump is located to the north of the NIR cluster and hosts a young high-mass star associated with an outflow that is observed in mid-IR, methanol maser and radio emission. We interpret this anatomy as the possible result of triggered star formation, starting with the formation of two HII regions, followed by the compression of a molecular gas filament in which a first generation of high-mass stars forms (the NIR cluster), which then triggers the formation of high mass protostars in its near environment (the massive protostellar binary). The global collapse of the northern clump might be due to both the expansion of the HII regions that squashes the filament. In conclusion, we witness the formation of four generations of clusters of high-mass stars in S255–S257.

Beginning with the winter season of 1995 and for the next ten years, the Antarctic Sub-mm Telescope and Remote Observatory (AST/RO, Stark et al. 1997; Stark et al. 2001; <http://www.cfa.harvard.edu/ASTRO/>), a 1.7m diameter, offset Gregorian telescope located at an altitude of 2847m at the Amundsen-Scott South Pole Station collected sub-mm and Terahertz data in the 1.3mm to 200μm wavelength bands. From its location just a few hundred meters away from the geophysical South Pole, AST/RO was the first sub-mm telescope to over-winter on the polar plateau, a location uniquely suited to high quality sub-mm observations due its very low humidity, high atmospheric stability and thin troposphere (Chamberlin et al. 1997).

Hydrodynamic and potentially also hydromagnetic instabilities play an important role in core-collapse supernovae. We report on simulations performed to investigate the effects of magnetic fields in simplified models. Furthermore, we present efforts to get rid of problems arising from the coordinate singularity at the symmetry axis and the associated boundary conditions.

Interstellar superbubbles generated by multiple supernova explosions are common in star-forming galaxies. They are the most obvious manifestation of mechanical feedback, and are largely responsible for transferring both thermal and kinetic energy to the interstellar medium from the massive star population. However, the details of this energy transfer remain surprisingly murky when individual objects are studied. I will summarize what we currently know about candidate dominant processes on these scales.

The Sun's magnetic field is produced throughout the solar interior; it emerges and is dispersed by surface and subsurface flows, and then expands above the surface to dominate the structure of the corona. To resolve the effects of the magnetic field it is necessary to image the interior and measure its rotation and flow systems; track the responses of the magnetic fields to flows in the surface; and to follow the evolution of structures in the corona. Because the Sun is dynamic both high spatial and temporal resolution are essential. Because the Sun's magnetic field effects encompass the entire spherical exterior, the entire surface and outer atmosphere must be mapped. And because the magnetic field is cyclic high-resolution observations must be maintained over multiple cycles.

We derive quantitative star formation histories (SFH) of the two dwarf spheroidal (KK 197 and ESO 269-066) and one dwarf irregular (ESO 381-018) galaxies in the nearby Centaurus A group. The data are part of our sample of about 50 nearby dwarf galaxies observed with the Advanced Camera for Surveys (ACS) at the Hubble Space Telescope (prog. 9771 & 10235, PI I.Karachentsev). Deep color-magnitude diagram (CMD) of KK 197 is shown in Fig.1.

We present preliminary analysis of an imaging survey of non-barred ringed galaxies (NBRGs). We have taken broadband, narrow band, and spectroscopic data for a sample of NBRGs selected from the Third Reference Catalogue of Bright Galaxies and the Catalogue of Southern Ringed Galaxies. These galaxies are the subject of a survey in order to (1) better understand the mode of ring formation in the absence of a strong bar and (2) delineate the general photometric and spectroscopic properties of this group as a whole.

We report new constraints on the local escape speed of our Galaxy. Our analysis is based on a sample of high velocity stars from the RAVE survey and two previously published datasets (the Geneva-Copenhagen survey and the Beers et al. catalogue of metal-poor stars). We use cosmological simulations of disk galaxy formation to motivate our assumptions on the shape of the velocity distribution, allowing for a significantly more precise measurement of the escape velocity compared to previous studies. We find that the escape velocity lies within the range 492 km s−1 < vesc <594 kms (90% confidence), with a median likelihood of 536 kms. The fact that v2esc is significantly greater than 2v2circ implies that there must be a significant amount of mass exterior to the Solar circle, i.e. this convincingly demonstrates the presence of a dark halo in the Galaxy. For a simple isothermal halo, one can calculate that the minimum radial extent is ~54 kpc. We use our constraints on vesc to determine the mass of the Milky Way halo for three halo profiles. For example, an adiabatically contracted NFW halo model results in a virial mass of 1.31+0.97−0.49 × 1012M⊙ and virial radius of 297+60−44 kpc (90% confidence). For this model the circular velocity at the virial radius is 141+27−19kms. Although our halo masses are model dependent, we find that they are in good agreement with each other.

We studied ~ 2 deg2 region in the Shapley Supercluster (SSC) core at z~0.05 in two bands (B and R). By studying the galaxy luminosity function (LF) and the colour distribution of galaxies we find that processes directly related to the supercluster environment are responsible for transforming faint galaxies, rather than galaxy merging.

Several (sub)millimeter-wave studies of nearby star-forming regions have revealed self-gravitating prestellar condensations that seem to be the direct progenitors of individual stars and whose mass distribution resembles the IMF. In a number of cases, small internal and relative motions have been measured for these condensations, indicating they are much less turbulent than their parent cloud and do not have time to interact before evolving into protostars and pre-main sequence stars. These findings suggest that the IMF is at least partly determined by pre-collapse cloud fragmentation and that one of the keys to understanding the origin of stellar masses lies in the physical mechanisms responsible for the formation and decoupling of prestellar cores within molecular clouds.

In a synthesis article (see ref. below), the double star expert Paul COUTEAU put the work of French pioneers of double stars observation in the perspective of the double star work carried in the world. After Antoine Yvon VILLARCEAU and Camille FLAMMARION, one prominent pioneer of double stars was Robert JONCKHEERE (1888–1974), an amateur before circumstances prompted him to become a professional astronomer, who devoted his life to double stars. Kenneth Glyn Jones wrote a biography and Charles Fehrenbach his obituary. Jean-Claude Thorel studied his life and career in double star observations (see Section 10 below). In the 1930s, another precursor of the Commission des Étoiles Doubles, Maurice DURUY (1894–1984) invented the micrometer with a comparison star, and applied the diffraction micrometer invented by Ejnar Hertzsprung to the measure of double stars, which he regularly observed at Nancy with a 275-mm telescope, at Lyon with a 162-mm telescope and in his observatory of Beaume-Mêle with a 40-cm and later a 60-cm telescope at Le Rouret (Alpes–Maritimes). He measured standard pairs of the list of Paul Muller and published his measures in the Journal des Observateurs; these measures requested by Paul Muller aimed at comparisons of between observers. He also collaborated with the Webb Society of Great Britain; Glyn Jones published his astronomical biography. Already in 1924, the pediatrician Paul BAIZE (1901–1995) had started the measurement of double stars as an amateur. He was granted permission to measure them with the 38-cm of the Paris Observatory and made an impressive number of measures during his long “career" (24044). He also made orbit calculations and established a formula for the calculation of dynamic parallaxes in 1946. He wrote articles explaining new observation techniques devoted to double stars in the magazine L'Astronomie and continued his astronomical activity until the beginning of the 1990s. Glyn Jones published an astronomical biography of Paul Baize. In the 1960s, Bernard CLOUET and the late Robert SAGOT (1910–2006) made double star observations for the book which was then in preparation under the title La revue des constellations. Their measures remained unpublished; but publication of the measures made by Robert SAGOT is in preparation. At about the same time, the neurology professor Jacques LE BEAU (1908–1998) made the acquaintance of renowned professional astronomer Paul COUTEAU and learned from him how to measure double stars. Each year, he stayed for two weeks at Nice and conducted his observations with the 50-cm refractor of the Nice Observatory. In 1978, Paul COUTEAU published the first book in French devoted to double stars: L'observation des étoiles doubles visuelles. That book triggered the interest of more amateur astronomers for double stars and indirectly influenced the creation of a group of double star observers which was transformed into the Commission des Étoiles Doubles

Planetary nebulae (PN) are favourite objects in the study of stellar populations both in the Galaxy and in other objects as well, due to their high brightness and the considerable range in their kinematic properties and chemical composition. In this work, we take into account available data samples of PN in Local Group galaxies and compare the derived information from different objects, particularly regarding their chemical composition, space distribution, kinematics, and the PN luminosity function.

Results of the Stardust mission to sample dust from comet Wild 2 are summarized.

We present two-dimensional (2D) gas kinematics and excitation of the inner 300 pc of the Seyfert galaxy ESO428-G14 at a sampling of 14 pc2, from near-infrared spectroscopic observations at R=5900 obtained with the Integral Field Unit of the Gemini Near-Infrared Spectrograph. Blue-shifts of up to 400 km s−1 and velocity dispersions of up to 150 km s−1, are observed in association with the radio jet running from SE to NW along position angle 129°. Both X-rays emitted by the active galactic nucleus and shocks produced by the radio jet can excite the H2 and [Fe ii] emission lines. We use the 2D velocity dispersion maps we estimate upper limits of 90% to the contribution of the radio jet to the excitation of [Fe ii]λ1.257μm, and of 80% to the excitation of H2λ2.121μm in the jet region.