The hot He-burning horizontal-branch (HB) stars and their progeny are most likely dominant ultraviolet (UV) sources in the old stellar population systems such as globular clusters (GCs). Integrated FUV flux can be an age indicator of GCs and allow us to investigate age distributions of GCs within a given galaxy or between galaxies. The unprecedented set of UV photometry for M31 by Galaxy Evolution Explorer (GALEX), coupled with most recent detailed population models enable to study detailed global UV properties of M31 GCs.

This report is a general introduction to Chinese major astronomical projects. It includes the ongoing project ‘Large Sky Area Multi-Object Fiber Spectroscopic Telescope’ (LAMOST), and three major projects which have finished their feasibility study and development of key technologies: Five-hundred-meter Aperture Spherical (radio) Telescope (FAST); Space Solar Telescope (SST); Hard X-ray Modulation Telescope (HXMT). Among them, FAST and HXMT have been approved by government in 2006, and SST is pending for the next five years plan. Besides these major projects, a site survey in the west of China, a plan for developing Antarctic Dome A for astronomy, and a preliminary study of Chinese future giant optical/infrared telescopes are also briefly introduced.

Radio galaxies are identified with the most massive host galaxies known out to z = 5 and can put strong constraints on galaxy evolution models, provided their space density is accurately determined. Here, I present the important role low-frequency radio surveys will have in this by selecting the highest redshift radio galaxies using the steepness of their radio spectra.

We explore the mass-assembly and chemical enrichment histories of star forming galaxies by applying a population synthesis method to a sample of nearly 70k galaxies culled from over 500k galaxies from the Sloan Digital Sky Survey Data Release 5. Our method decomposes the entire observed spectrum in terms of a sum of simple stellar populations spanning a wide range of ages and metallicities, thus allowing the reconstruction of galaxy histories. A comparative study of galaxy evolution is presented, where galaxies are grouped onto bins of nebular abundances or mass. We find that galaxies whose warm interstellar medium is poor in heavy elements are slow in forming stars. Their stellar metallicities also rise slowly with time, reaching their current values (Z⋆ ~ 1/4Z⊙) in the last ~100 Myr of evolution. Systems with metal rich nebulae, on the other hand, assembled most of their mass and completed their chemical evolution long ago, reaching Z⋆ ~ Z⊙ already at lookback times of a few Gyr. These same trends, which are ultimately a consequence of galaxy downsizing, appear when galaxies are grouped according to their stellar mass. The reconstruction of galaxy histories to this level of detail out of integrated spectra offers promising prospects in the field of galaxy evolution theories.

It has been established that massive stars form in dense clusters, when large molecular clouds collapse. However, the high obscuration and small spatial scales make it difficult to investigate the earliest stage of high–mass protostellar objects (HMPOs). Therefore methanol masers are of special interests as they are closely associated with HMPOs and offer high spatial resolution; they probe the massive star formation environment at the unique scale of a few AU (1 mas corresponds to 5 AU at 5 kpc).

We present VLBI observations of methanol masers discovered in an unbiased survey along the Galactic plane. We compare their positions with infrared surveys. In general, the masers do not coincide with infrared objects. That implies they are already present at a very early evolution stage of HMPOs when the dense surroundings still absorb other radiation. In addition we present maps of five methanol masers towards HMPOs with milliarcsecond resolution taken with the recently extended European VLBI Network. These sources show a wide variety of morphologies, indicating they arise in different events going on in close surroundings of HMPOs, i.e. outflows, discs or shocks. One source G23.657−00.127 displays a regularly shaped ring which appears as a great laboratory for further research of a single HMPO. Proper motion studies should reveal an expansion or rotation of the maser components in 2–3 years.

The hot molecular core, W3(H2O), contains a massive protobinary system that is cocooned by dense gas (n(H2) ~ 107 cm−3), with about 1 arcsec (~ 2000 AU) separation of the binary system. We investigate chemical properties of the gas components around this binary system using the mm-wave transitions of complex molecules, CH3CN, SiO, HNCO, and CH3CH2CN, observed with the BIMA array. The two protostellar objects, A and C in W3(H2O), can be distinguished using chemical properties, suggesting that the source A may be younger than the source C within the time scale of less than 104 years. The hot core around the source C, traced by CH3CH2CN and the K=6 component of CH3CN, seems to have more time for chemical evolution than the source A. The SiO emission in this region suggests that there was an influence from the outside of the W3(H2O) and W3(OH) hot cores. The nitrogen chemistry may be more active in the later stage than the oxygen chemistry, but the chemical evolution of the protostellar envelopes may not be monotonic as previously suggested.

The eccentricities of catalogued binaries show that tidal interactions extend to periods of at least 1000 days. The maximum periods for complete circularization probably depend on age, rather than mass. For the longest periods all eccentricities are equally probable. For shorter periods the highest eccentricities disappear first. For the same periods, the SB2's have larger mean eccentricities than the SB1's, in accord with Keplers Third Law.

It is known that most of stars are formed as clusters (Lada & Lada 2003, ARAA 41, L57) and clusters are formed by triggering. However, the relationships of molecular clouds' conditions and properties of formed stars by triggering is not well studied. To clarify differences between triggered and spontaneous star formation through physical properties of molecular clouds (e.g. mass, density, morphology), we observed the W5-East HII region. The W5-East HII region is located at 2 kpc and has a 10 pc extent of HII region. This region has 3 Bright Rimmed Clouds (BRCs; Sugitani et al. 1991, ApJS 77, S59), which are interface between HII regions and molecular clouds, and known as sites of triggered star formation. The molecular clouds surround the W5-East (Karr et al. 2003, ApJ, 595, 900), thus we expect molecular clouds morphology is affected by the HII region and the cloud evolution is supposed to be dominated by the expanding HII region.

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.