The first stars are key to the formation of primeval galaxies, early cosmological reionization, and the assembly of supermassive black holes. Although Population III stars lie beyond the reach of direct observation, their chemical imprint on long-lived second generation stars may yield indirect measures of their masses. While numerical models of primordial SN nucleosynthetic yields have steadily improved in recent years, they have not accounted for the chemical abundances of ancient metal-poor stars in the Galactic halo. We present new two-dimensional models of 15 - 40 M⊙ primordial SNe that capture the effect of progenitor rotation, mass, metallicity, and explosion energy on elemental yields. Rotation dramatically alter the structure of zero-metallicity stars, expanding them to much larger radii. This promotes mixing between elemental shells by the SN shock and fallback onto the central remnant, both of which govern which elements escape the star. We find that a Salpeter IMF average of our yields for Z=0 models with explosion energies of 2.4 × 1051 ergs or less is in good agreement with the abundances measured in extremely metal-poor stars. Because these stars were likely enriched by early SNe from a well-defined IMF, our models indicate that the bulk of the metals in the early universe were synthesized by low-mass primordial stars.

The thermosphere is the transition region from the atmosphere to space. Both the solar ultraviolet radiation and the solar wind energy inputs have caused significant thermospheric variations from past to present. In order to understand thermospheric/ionospheric disturbances in association with changes in solar activity, observational and modelling efforts have been made by many researchers. Recent satellite observations, e.g., the satellite CHAMP, have revealed mass density variations in the upper thermosphere. The thermospheric temperature, wind, and composition variations have been also investigated with general/global circulation models (GCMs) which include forcings due to the solar wind energy inputs and the lower atmospheric effects. In particular, we have developed a GCM which covers all the atmospheric regions, troposphere, stratosphere, mesosphere, and thermosphere, to describe variations of the thermospheric temperature and density caused by both effects from the lower atmosphere and the magnetosphere. GCM simulations represent global and localized temperature and density structures, which vary from hour to hour, depending on forcings due to the lower atmosphere, solar and geomagnetic activities. This modelling attempt will enable us to describe the thermospheric weather influenced by solar activity in cooperation with ground-based and satellite observations.

Solar activity is a determining factor for space climate of the Solar system. Thus, predicting the magnetic activity of the Sun is very important. However, our incomplete knowledge about the dynamo processes of generation and transport of magnetic fields inside Sun does not allow us to make an accurate forecast. For predicting the solar cycle properties use the Ensemble Kalman Filter (EnKF) to assimilate the sunspot data into a simple dynamo model. This method takes into account uncertainties of both the dynamo model and the observed sunspot number series. The method has been tested by calculating predictions of the past cycles using the observed annual sunspot numbers only until the start of these cycles, and showed a reasonable agreement between the predicted and actual data. After this, we have calculated a prediction for the upcoming solar cycle 24, and found that it will be approximately 30% weaker than the previous one, confirming some previous expectations. In addition, we have investigated the properties of the dynamo model during the solar minima, and their relationship to the strength of the following solar cycles. The results show that prior the weak cycles, 20 and 23, and the upcoming cycle, 24, the vector-potential of the poloidal component of magnetic field and the magnetic helicity substantial decrease. The decrease of the poloidal field corresponds to the well-known correlation between the polar magnetic field strength at the minimum and the sunspot number at the maximum. However, the correlation between the magnetic helicity and the future cycle strength is new, and should be further investigated.

We obtained long-slit spectra of high S/N of the galaxy M32 with the GMOS Spectrograph at the Gemini-North telescope. We analysed the integrated spectra by means of spectral fitting in order to extract the mixture of stellar populations that best represents its composite nature. As our main result, we propose that an ancient and an intermediate-age population co-exist in M32, and that the balance between these two populations change between the nucleus and outside one effective radius (1reff) in the sense that the contribution from the intermediate population is larger at the nuclear region. We retrieve a smaller signal of a young population at all radii whose origin is unclear, and may be a contamination from horizontal branch stars, blue stragglers or a true young population previously unidentified (Monachesi et al., this volume). We compare our metallicity distribution function for a region 1 to 2 arcmin from the centre to the one obtained with photometric data by Grillmair et al. Both distributions are broad, but our spectroscopically derived distribution has a significant component with [Z/Z⊙] ≤ −1, which is not found by Grillmair et al.

We have examined in detail both the resolved and integrated stellar content of a representative sample of galaxies in the Virgo cluster to constrain plausible formation/evolution scenarios for them. Systematic variations in age and metallicity gradients along the Hubble sequence are found such that the gradients become more negative for later types. Combined with correlations of the above stellar properties with both structure and environment, these data highlight the significance of merging in the assembly of massive spheroids and environmental phenomena (gas removal/interactions) in the evolution of disks and dwarf systems. Our data also provide useful perspectives on a number of important topics in the recent literature.

Our knowledge about the chemical evolution of the more luminous dwarf spheroidal (dSph) galaxies is constantly growing. However, little is known about the enrichment of the ultrafaint systems recently discovered in large numbers in large Sky Surveys. Low-resolution spectroscopy and photometric data indicate that these galaxies are predominantly metal-poor. On the other hand, the most recent high-resolution abundance analyses indicate that some of these galaxies experienced highly inhomogenous chemical enrichment, where star formation proceeds locally on the smallest scales. Furthermore, these galaxy-contenders appear to contain very metal-poor stars with [Fe/H]< −3 dex and could be the sites of the first stars. Here, we consider the presently available chemical abundance information of the (ultra-) faint Milky Way satellite dSphs. In this context, some of the most peculiar element and inhomogeneous enrichment patterns will be discussed and related to the question of to what extent the faintest dSph candidates and outer halo globular clusters could have contributed to the metal-poor Galactic halo.

This brief paper summarizes a “key general review” with the same title given at the IAU meeting in Rio de Janeiro. The intent of the review talk was to give a broad and well-illustrated overview of recent work on the icy middle and outer Solar system, in a style interesting for those astronomers whose gaze is otherwise drawn to more distant realms. The intent of this written review is the same.

Understanding the details of how the red sequence is built is a key question in galaxy evolution. What are the relative roles of gas-rich vs. dry mergers, major vs. minor mergers or galaxy mergers vs. gas accretion? In a recent paper (Wild et al. 2009), we compare hydrodynamic simulations with observations to show how gas-rich major mergers result in galaxies with strong post-starburst spectral features, a population of galaxies easily identified in the real Universe using optical spectra. Using spectra from the VVDS deep survey with <z> = 0.7, and a principal component analysis technique to provide indices with high enough SNR, we find that 40% of the mass flux onto the red-sequence could enter through a strong post-starburst phase, and thus through gas-rich major mergers. The deeper samples provided by next generation galaxy redshift surveys will allow us to observe the primary physical processes responsible for the shut-down in starformation and build-up of the red sequence.

In March 2004 the European Space Agency launched its Planetary Cornerstone Mission Rosetta to rendezvous with Jupiter-family comet 67P/Churyumov-Gerasimenko. The Rosetta mission represents the next step into the improvement of our understanding of comet nuclei naturally following the four successful comet nucleus fly-by missions carried out in the past. It will however not perform a simple fly-by at its target comet, but combines an Orbiter and a Lander Mission. The Rosetta spacecraft will go in orbit around the comet nucleus when it is still far away from the Sun, and escort the comet for more than a year along its pre- and post-perihelion orbit while monitoring the evolution of the nucleus and the coma as a function of increasing and decreasing solar flux input. Different instrumentations will be used in parallel, from multi-wavelength spectrometry to in-situ measurements of coma and nucleus composition and physical properties. In addition the Rosetta Lander Philae will land on the nucleus surface, before the comet is too active to permit such a landing (i.e. at around r = 3 AU) and examine the surface and subsurface composition as well as its physical properties. Two fly-bys at main belt asteroids have been scheduled for the Rosetta spacecraft during its journey to the comet. The first fly-by at E-type asteroid (2867) Steins was already successfully executed in September 2008. The second and main fly-by at asteroid (21) Lutetia is scheduled for July 2010.

Integrated optical spectra of star clusters in the Magellanic Clouds and a few Galactic globular clusters are fitted using high-resolution spectral models for single stellar populations. The goal is to estimate the age, metallicity and extinction of the clusters, and evaluate the degeneracies among these parameters. Several sets of evolutionary models that were computed with recent high-spectral-resolution stellar libraries (MILES, GRANADA, STELIB), are used as inputs to the starlight code to perform the fits. The comparison of the results derived from this method and previous estimates available in the literature allow us to evaluate the pros and cons of each set of models to determine star cluster properties. In addition, we quantify the uncertainties associated with the age, metallicity and extinction determinations resulting from variance in the ingredients for the analysis.

The value of different forms of energy contained in TDC region as well as the structure and physical characteristics of star formation in the Taurus Dark Clouds are analyzed.

Recent detailed studies of narrow absorption line (NAL) systems in QSO spectra have revealed that at least 50% of QSOs have NALs associated with the central engine, and in most cases they are found to be outflowing. Will studies of NALs provide the much sought-after evidence for ubiquitous QSO feedback that can halt the formation of stars in galaxies? I present new results on the distribution of line-of-sight velocity offsets between Mg ii absorbers and their background QSOs, based on a large catalogue of absorbers from SDSS DR6 and greatly improved QSO redshift estimates. The analysis reveals high velocity Mg ii NALs out to at least 6000 km s−1 from the QSO, which cannot be ascribed to the clustering of local galaxies, similar to that observed for C iv absorbers. The existence of such low-ionization, high-velocity gas clouds in the intense ionixing field of the QSO suggests that we may indeed be witnessing the mechanical expulsion of gas, alongside the heating previously observed. We also find an excess of low-velocity Mg ii NALs in radio-loud QSOs compared to radio-quiet QSOs, consistent with their different clustering amplitudes.

Accretion onto the massive black hole at the centre of a galaxy can feed energy and momentum into its surroundings via radiation, winds, and jets. Feedback due to radiation pressure can lock the mass of the black hole onto the MBH–σ relation, and shape the final stellar bulge of the galaxy. Feedback due to the kinetic power of jets can prevent massive galaxies greatly increasing their stellar mass by heating gas, which would otherwise cool radiatively. The mechanisms involved in cosmic feedback are discussed and illustrated with observations.

We have developed a new procedure to search for Carbon-Enhanced Metal-Poor (CEMP) stars from the Hamburg/ESO (HES) prism-survey plates. This method uses an extended line index for the CH G-band, which we demonstrate to have superior behavior when compared to the narrower G-band index formerly employed for these spectra.

A first subsample, biased towards brighter stars (B<15.5), has been extracted from the scanned HES plates. After visual inspection (to eliminate spectra compromised by plate defects, overlapping spectra, etc., and to carry out rough spectral classifications), a list of 669 previously unidentified candidate CEMP stars was compiled. Follow-up spectroscopy for a pilot sample of 132 candidates was obtained on the SOAR 4.1m telescope. Our results show that most of the stars observed lie in the targetted metallicity range, and possess prominent carbon absorption features at 4300Å. The success rate for the identification of new CEMP stars is ~50% for [Fe/H]< −2.0. For stars with [Fe/H]< −2.5, the ratio increases to 100%.

The atmospheric response to the 11-year solar cycle is studied using the fully interactive 3-D coupled chemistry-general circulation model LMDz-REPROBUS with a complete seasonal cycle. We will show results concerning a comparison between two series of 20-year runs, one in maximum of activity and the other in minimum. The stratosphere-troposphere system shows partly significant response to a solar cycle enhancement of UV radiation. We show how the changes in stratospheric ozone, temperature and zonal wind are connected.

We have studied Hubble Space Telescope archive imagery of the central region of the Seyfert 2 galaxy NGC 5427. The images were taken with F606W (V-band) and F160W (H-band) filters with the Wide Field and Planetary Camera 2 and the Near Infrared Camera and Multi-Object Spectrometer, respectively.

The UV upturn phenomenon found in giant elliptical galaxies through space observations has been a mystery. Recent GALEX observations have revealed new facts. The most notable is the rarity of UV upturn galaxies. Unlike previous beliefs, UV upturn is found only in less than 10 percent of giant ellitpical galaxies. Another notable finding is that the UV flux has been increasing for the last couple of billion years. This is consistent with the theoretical predictions that suggest hot horizontal branch stars are the main UV sources. Remaining theoretical and observational issues on this topic can be found in another recent review of mine (Yi 2008).

During this last decade our knowledge of the evolutionary properties of stars has significantly improved. This result has been achieved thanks to our improved understanding of the physical behavior of stellar matter in the thermal regimes characteristic of the different stellar mass ranges and/or evolutionary stages.

This notwithstanding, the current generation of stellar models is still affected by several, not negligible, uncertainties related to our poor knowledge of some thermodynamical processes and nuclear reaction rates, as well as the efficiency of mixing processes. These drawbacks have to be properly taken into account when comparing theory with observations, to derive evolutionary properties of both resolved and unresolved stellar populations.

In this paper we review the major sources of uncertainty along the main evolutionary stages, and emphasize their impact on population synthesis techniques.

Recent numerical relativity simulations predict that coalescing supermassive black holes (SMBHs) can receive kick velocities up to several thousands of kilometers per second due to anisotropic emission of gravitational waves, leading to long-lived oscillations of the SMBHs in galaxy cores and even SMBH ejections from their host galaxies. Observationally, accreting recoiling SMBHs would appear as quasars spatially and/or kinematically offset from their host galaxies. The presence of these “kicks” and “superkicks” has a wide range of exciting astrophysical implications which only now are beginning to be explored, including consequences for black hole and galaxy growth at the epoch of structure formation, modes of feedback, unified models of AGN, and the number of obscured AGN. SMBH recoil oscillations beyond the torus scale can be on the order of a quasar lifetime, thus potentially affecting a large fraction of the quasar population. We discuss how this might explain the long-standing puzzle of a deficiency of obscured type 2 quasars at high luminosities. Observational signatures of recoiling SMBHs are discussed and results from follow-up studies of the candidate recoiling SMBH SDSSJ0927+2943 are presented.

Several authors have studied the dependence of galaxy properties on environment in order to understand which mechanisms operate in the galaxy evolution. Recently, some of them have proposed that intermediate densities could be sites where local environment influences the transition of galaxies onto the red-sequence, as opposed to mechanisms that operate on cluster scales. Based on the evidence that interacting and merging systems are frequent at intermediate densities, we use the SDSS-DR4 data to analyse the role of close galaxy interactions as an environmental process which could contribute to lead evolutionary transformations. We explore the properties of galaxy pairs at different local and global density environments, comparing them with those of isolate galaxies in an unbiased control sample (CS).