The South Pole Telescope survey of 2500 deg^2 in the southern sky has enabled the selection of a large sample of massive galaxy clusters extending to z~1.5 through their Sunyaev-Zel'dovich effect. Dark Energy Survey deep, optical multiband imaging is enabling studies of the galaxy populations within those clusters and constraints on the masses of the systems through weak lensing. Analyses of the population of SZE selected clusters from SPT indicates cosmological constraints that are in good agreement with other cosmological probes and that together with other probes provide among the most precise constraints yet on the growth rate of cosmic structure and the equation of state of the dark energy. Improved mass constraints from weak lensing and new cluster finding experiments in the X-ray through eROSITA promise to open the window on new studies of cosmology and structure evolution.

Neutrinos are surely the most enigmatic fundamental particles in Nature. Wolfgang Pauli postulated the neutrino as an undetectable particle, however nowadays neutrinos can be detected routinely thanks to very large advanced detectors. Many of the developments in the neutrino field were triggered by the pioneering experiment of Ray Davis observing too few neutrinos from the Sun compared to expectations. Surprisingly the solar neutrino problem was caused by our incomplete understanding of the particle physics. The solution was: Neutrinos have mass and oscillate, changing from one flavor to another. It was for these findings that the Nobel Prize in Physics 2015 was awarded to Takaaki Kajita (from Super-Kamiokande Experiment) and Arthur B. McDonald (from SNO Experiment). Sudbury Neutrino Observatory Collaborations. The talk will retrace the history of the neutrino and discoveries in the neutrino field. A particular focus will be on the discovery of neutrino oscillations. Future efforts in neutrino oscillation physics and neutrino astronomy will be discussed and their potential for more discoveries evaluated.

Gaia is an ESA satellite project launched at Dec. 2013. It will map our Galaxy in 3D by measuring six astrometric parameters (i.e. two positions, two proper motions, parallax, and radial velocity) of one billion stars over the whole sky. Astrometric accuracy of Gaia for G type star is 5-16 μas for bright stars, 24 μas at V = 15 mag and 540 μas at V = 20 mag, which is the highest accuracy that has ever been achieved. Gaia simultaneously obtains low-resolution spectrum of each star using Blue and Red Photometer (BP and RP: 330-680nm and 640-1000nm, respectively). By the nature of Gaia, it will produce enormous amount of complex data. Analyzing Gaia data is thus a challenging and huge task requiring big-data experts and dedicated computing powers as well. In this talk, I will give an overview of the Gaia mission and efforts for Gaia data analysis in DPAC (Data Processing and Analysis Consortium).

The early phases of supernovae (SNe) reveal very important characteristics of their stellar progenitors and their explosion mechanisms. On the one hand, the shock breakout, which is the first electromagnetic signature occuring when the shock emerges at the surface, carries key information on the structure of the exploding star. Secondly, for core-collapse SNe the rise behaviour is directly related to the properties of the collapsing star while for thermonuclear SNe the unknown companion of the exploding white dwarf can leave an imprint in the first hours to days of the light-curve. We present past and current results of early light-curve studies of different SN types and lay out the exciting landscape that the new high-cadence surveys like the KMTNet Supernova Project (KSP) and the High-cadence Transient Survey (HiTS) will bring along.

Brown dwarfs are the objects that bridge the realms of stars and planets, making them important benchmarks for testing star and planet formation theories. In particular, studies of brown dwarfs at young ages are crucial for understanding the mass dependence in the formation and early evolution of stars. Star forming regions and young clusters harbour large populations of these substellar objects, including some with masses comparable to those of giant planets. Our deep survey SONYC (Substellar Objects in Nearby Young Clusters) was designed to provide a census of the substellar population in nearby star forming regions, and characterize their Initial Mass Functions down to unprecedented masses below 10 MJup. In this talk I will present the current status of the studies of the low-mass IMF, discuss the effects of environment, and outline the impact on our understanding of star formation.

Galaxies are the end product of the hierarchical universe. Understanding them thus requires reliable physics on all scales, from individual stellar populations to structure formation. As an ab-initio approach, semi-analytic models (SAMs) for galaxy formation and evolution are widely used to investigate galaxy properties. In this talk, I will give a brief introduction of a new SAM, ySAM, which has been developed by utilising halo merger trees extracted from N-body simulations and up-to-date physical prescriptions. Since halo merger trees are the essential backbones of SAMs, the impact of different halo merger tree building algorithms on ySAM will be presented. Galaxy mergers and in-situ star formation are considered to be two main channels for galaxy mass growth. I will show the contribution of mergers to stellar mass assembly histories according to the wide range of halo and galaxy mass. Finally, I will briefly report some issues on galaxy chemical evolution in ySAM.

Materials exposed to the harsh space environment are altered over time in both physical and compositional properties. The general definition of space weathering simply refers to this alteration. There are multiple processes, however, that can and do alter materials on the surface of an airless body: comminution, melting, vaporization by energetic impacts; gardening of a particulate soil and mixing with local and foreign materials by repeated impacts; sputtering at the atomic/molecular scale by solar wind; crystal damaging by UV radiation and energetic particles; structural fatigue from diurnal thermal cycling; mobility or loss of volatile species by radiant heating and sublimation; etc. Thus, space weathering takes many forms and its alteration products are a direct function of a) location in the solar system, b) composition and texture of the surface, c) mass and magmatic evolution of the body, and d) length of time exposed. The regolith of only two extraterrestrial bodies has been directly sampled (The Moon and Itokawa). These samples and the ongoing detailed analyses in Earth-based laboratories provide a cornerstone for recognizing and understanding some aspects of space weathering effects. A handful of additional bodies have been visited by spacecraft and studied in detail for extended periods with remote sensors (Mercury, Eros, Vesta, and most recently the dwarf planet Ceres and comet Churyumov-Gerasimenko). Seven additional asteroids have been observed with instruments during a spacecraft flyby, while the satellites of Mars, Jupiter, and Saturn, have been studied to different degrees through multiple flybys. A few of the various forms of space weathering that are now recognized (or hypothesized) will be discussed and illustrated.

Prior to the year 2005, the number of known “classical” Milky Way (MW) dwarf satellite galaxies (?8 mag > Mv > ?18 mag) remained twelve. However from 2005 to the present, thanks to the high quality photometric data from extremely well designed systematic surveys such as Sloan Digital Sky Survey (SDSS; York et al. 2000) or Dark Energy Survey (DES; Abbot et al. 2005), the number of newly discovered faint dwarf satellites has dramatically increased: Now we have almost forty dwarf satellite galaxies in the halo of the Milky Way (e.g., 15 ultra-faint dwarfs from SDSS; 17 dwarf galaxy candidates from the first two-year data set of DES), and there might be more than tens of faint dwarf satellites still waiting to be discovered in the near future (Koposov et al. 2007; Tollerud et al. 2008). In this talk, I will give a quick guided tour on these near-field dwarf galaxy populations. For in-depth review, we will take a look at several specific case studies on the properties of dwarf satellite galaxies in the Local Group and nearby Sculptor filament. Finally I will close my talk by introducing the usage of “RR Lyrae variable stars” as a versatile probe to “old stellar halos” of nearby galaxies.

The World Space Observatory Ultraviolet (WSO-UV) is the space mission that will grant access to the UV range in the post Hubble epoch. WSO-UV is equipped with instrumentation for imaging and spectroscopy and it is fully devoted to UV astronomy. In this talk, we outline the WSO-UV mission model and present the current status of the project. Also, the NEO observing mission SODA (System of Observation of Day-time Asteroids) is also presented.

The ASIAA is leading an effort to deploy the 12m ALMA-NA prototype telescope to the Summit of Greenland. We have been retrofitting this telescope for operations at polar conditions, and we will ship the telescope to Thule in Greenland in 2016. The scientific target is to image the shadow of the supermassive black hole in the nucleus of the M87 galaxy. Although at a distance of 18Mpc, the M87 SMBH is almost as large in apparent size as the SgrA* SMBH in the Milky Way. The shadow is expected to be on the order of 40 micro arsec. By using the GLT as the northern station of a VLBI experiment which will include ALMA, the SMA, and the JCMT, we aim to achieve 20 micro arsec resolution at 350GHz. The GLT will be the first astronomical observatory in the Arctic region. In this talk, we will report on the current status of this project.

Gamma-Ray Bursts (GRBs) are the most energetic explosions in the universe. We have already known the most distant GRBs at the redshift z=8.26 (spectroscopic) and z=9.4 (photometric), so we can use GRBs as the cosmological probing tool. However we could obtain little knowledge of physical conditions in the early universe from these high-z GRBs while their redshifts were measured. We hope to perform the high dispersion spectroscopy with the large area telescopes during the afterglows are still bright. Then we can challenge to reveal the reionization epoch and the origins, early metal enrichment, star formation history as well as to detect GRBs from first stars (population-III stars). Japanese GRB community has organized a working group of a future small satellite mission, named "HiZ-GUNDAM" (High-z Gamma-Ray Bursts for Unraveling the Dark Ages Mission), to pioneer the observation of early universe with high-z GRBs. This mission consists of two instruments, the X-ray imaging system with coded aperture mask and the optical/near infrared telescope with 30cm diameter. Once GRBs are detected and localized, HiZ-GUNDAM rapidly perform the follow-up observation like the Swift satellite, and determine the rough redshift with the photometric observation with the optical/NIR telescope. The onboard measurement of redshift and the redshift alert system will play an important role in leading the follow-up observation for the early afterglows by large area telescope. The X-ray imaging system continuously monitors a large field of view of ~1 steradian in the energy range of 1-20 keV with the effective area of 500-1,000 cm2. We are developing 1-dimensional silicon strip sensor with the size of 19.2mm x 16mm (~3 cm2), and which has 64ch strip-type electrode with the width of 0.3mm. We are also developing the 64ch specific ASICs which is modified version of ones developed by Prof. Takahashi and Prof. Ikeda group in ISAS/JAXA. According to the current simulations by T-SPICE electric circuit simulator, they have enough gain to readout the small charges from 1 keV X-ray photon, and we can integrate appropriate trigger system. Using the coded aperture mask with the same pitch of 0.3mm at the distance of 30cm from the detector plane, we can determine the position of GRBs with ~10 arcmin accuracy in geometrically and ~5 arcmin for bright GRBs. Since the high-z GRBs have low brightness with long time duration because of the cosmological time dilation, we will enhance so-called imaging trigger system. The optical/NIR telescope has the primary mirror with 30cm in diameter, and we consider the offset Gregorian optics to avoid the stray light from the sun and the earth. We will divide the optical ray of 0.5--1.7 um into 4 bands with dichroic mirror, and perform the photometric observations and select the candidates of high-z GRBs. A reflection baffle (aperture shade) in front of the telescope gives us the wide visibility larger than the field of view of X-ray imaging system. Therefore we effectively perform the follow-up observations for GRBs detected by the X-ray detector. In this talk, we introduce the concept of HiZ-GUNDAM mission and the developing/planning instrumentations.

Despite the fact that the APOGEE project is focused on the structure of the galaxy, it also offers a lot to explore for stellar astrophysicists. In this colloquium, I will talk about two projects which are using the dwarf M (dM) stars in APOGEE. The first project is searching for HW Vir type (subdwarf B (sdB) + dM / brown-dwarf) systems, which are believed to compose a high percentage of subdwarfs despite not proven yet. The aim is to look at the IR spectra of dM stars in order to find a trace of an sdB companion. The results would reveal the binarity nature of sdB stars and common-envelope evolution, and contribute to the theoretical and evolutionary studies of sdBs through dM stars. The second project is to to define a chromospheric activity indicator in IR region by using active and inactive dwarf M stars' spectra and determine candidates for a 'Chromospherically Active Cool Stars Survey'.

The planet crossing asteroids in the inner solar system have strongly chaotic orbits and the distributions of their angular elements are often regarded as uniform random. We quantified the level of intrinsic non-uniformities of the angular elements for the dynamical subgroups of Near Earth Objects (NEOs) and Mars Crossing Objects (MCOs). Using the methods of angular statistics, we found several statistically significant departures from uniform random angular distributions. These non-uniform distributions of the angular elements may affect the asteroidal impact fluxes on the planets. We developed a new approach that accounts for the non-uniform angular elements of planet crossing asteroids to investigate the impact flux and its seasonal variation on the Earth, the Moon, and Mars. The impact flux of NEOs on the Earth-Moon system is found to be not affected significantly by the non-uniform distribution of angular elements of NEOs. The impact flux on Mars, however, is found to be reduced by a factor of about 2 compared to the flux that would obtain from the assumption of uniform random distributions of the angular elements of MCOs. Moreover, the impact flux on Mars has a strong seasonal variation, with a peak when the planet is near aphelion. We found that the amplitude of this seasonal variation is a factor of 4-5 times smaller compared to what would be obtained with a uniform random distribution of the angular elements of MCOs. We calculate that the aphelion impact flux on Mars is about three times larger than its perihelion impact flux.

The European Southern Observatory (ESO) is an intergovernmental astronomy organisation that provides state-of-the-art research facilities in Chile to astronomers in Europe and all over the world. Engineers, administrative staff, astronomers, scientists and many more, based in Chile and Germany, work together to keep ESO one of the world's most productive astronomical observatories. ESO astronomers are also very active in their own research fields, covering topics from exoplanets to high-redshift cosmology. I will give a brief introduction about the current activities of ESO and will highlight how ESO astronomers manage to combine their functional work with conducting forefront science. In the second part of my presentation, I will focus on my own scientific work. More than 16 years ago, so-called 'Ultra-Compact Dwarf galaxies' (UCDs) have been discovered in spectroscopic surveys of the Fornax galaxy cluster by our team. UCDs have a special place in the fundamental plane of pressure supported stellar systems. They are located at the high mass end of the globular cluster (GC) distribution, reaching ~10^8 M_sun and obey a mass-size relation unlike 'classical' GCs, but connecting to compact ellipticals. Nowadays, dozens, if not hundreds, of UCDs and their fellow `dwarf galaxy transition objects' (DGTOs), `giant globular clusters' (GGCs) and `extended clusters' (ECs) have been identified in various environments, filling the space in the fundamental plane between star clusters and dwarf galaxies. I will review the knowledge we obtained over the last 16 years of these sometimes still puzzling objects. I will present the occurence, spatial distribution, dynamics and mass spectrum of UCDs in different environments. For some of the bright UCDs, internal properties (metallicity, ages, [alpha/Fe] abundances, internal kinematics, clues to their IMF, etc.) are available, which I will highlight. Finally, I will summarize our current ideas about their formation and will conclude that the majority of UCDs belong to the 'star cluster family'.

Circumstellar disks of young stellar objects (YSOs) at a later stage are often called protoplanetary disks, as they are the natal place of protoplanets. In this talk, we present continuum observations at λ = 1.3 and 2.7 mm using the Combined Array for Research in Millimeter-wave Astronomy toward six protoplanetary disks in the Taurus molecular cloud: CI Tau, DL Tau, DO Tau, FT Tau, Haro 6-13, and HL Tau. We constrain physical properties of the disks with Bayesian inference using two disk models: the flared power-law disk model and flared accretion disk model. Comparing the physical properties, we find that the more extended disks are less flared and that the dust opacity spectral index (β) is smaller in the less massive disks. In addition, disks with a steeper mid-plane density gradient have a smaller β, which suggests that grains grow and radially move. We also discuss the possibilities of substructures on three extended protoplanetary disks. Furthermore, the HL Tau disk images taken by the Atacama Large Millimeter/submillimeter Array (ALMA) are shown and discussed. If time is allowed, disk formation at earlier stages of YSOs would be addressed as well.

We have explored GALEX UV properties of optical red sequence galaxies in 4 rich Abell clusters at z ? 0.1. Inparticular we tried to find a hint of merger-induced recent star formation (RSF) in the red sequence galaxies. RSF fractions are calculated with various criteria for post-merger galaxies and normal red sequence galaxies based on their NUV - r’ colors. In this study it turned out that only 30% of the RSF red sequence galaxies involve tidally-disturbed features in cluster environment. It is possible that we are missing minor merger features with the deep optical images from the less massive regime (-21 < Mr' < -20) of our volume-limited sample. However, considering the timescale difference for the fading out of morphological merger features (~ 4 Gyr) and young stellar populations (~ 1 Gyr), the fraction of RSF red sequence galaxies without disturbed features is still significantly large. We also confirmed that those featureless RSF galaxies are mostly bulge-dominated. This result may imply that gas accretion in early-type galaxies plays a significant role in residual star formation of the early-type galaxies.

A number of different scenarios have been proposed to explain the formation of massive stars. These include formation through the merger of less massive stars (coalescence model) or through the accretion of unbound gas from the molecular cloud (competitive accretion model). In the third scenario, the core accretion model, massive stars form through gravitational collapse, which involves disc-assisted accretion to overcome radiation pressure. This scenario is similar to the favored picture of low-mass star formation. Despite the likely importance of magnetic fields in the formation of low-mass stars, there are still only a few observations around massive stars, and theoretical simulations match the observations as long as the magnetic field is taken into consideration. Therefore, providing new measurements of magnetic fields orientation and strength at milliarcsecond resolution is fundamental to understand the formation process of high-mass stars. The best probes of magnetic fields in the high density regions close to massive protostars currently available are masers. In particular 6.7-GHz methanol and 22-GHz water masers. In the last six years we have studied the magnetic field around several massive young stellar objects by observing the polarized emission of water and, mainly, methanol masers. In my colloquium I will go through the results that we have achieved so far by emphasizing the most interesting cases.

Ghana has been enjoying space products for its socio-economic development for decades. Therefore, the idea of Ghana Space Science and Technology Center was conceived in 20008 but it was not until 2011 that the Centre was officially launched. The Centre has subsequently been upgraded into an Institute with three (3) research Centers, namely Radio Astronomy and Astrophysics, Remote Sensing and Climate Change, and Satellite Communication and Engineering. The Institute‘s mandate is to exploit the capabilities of Space Science and Technology for socio-economic development and to coordinate all Space related activities in Ghana. The Institute is engaged in joint projects and collaborations with partners globally. This presentation is to give an overview of activities at the Institute and also to showcase the opportunities for joint projects, capacity building and partnerships.

The Kepler space mission has discovered many planets around other stars, some of which are in the so-called habitable zone. In order for these planets to harbour terrestrial-type life, it is imperative that they experience a stable climate on long time scales. Earth experiences regular ice ages caused by perburbations from the other planets that cause the so-called Milankovic cycles. Such climate changes induced by the dynamics of the planetary system must be kept to a minimum. Here we report a case study of long-term climate cycles on the super-Earth HD 40307 g and extend this methodology to other systems.