My presentation is divided into two parts: the first part retraces chronologically all the main achievements accomplished within the framework of this Thematic Initiative; the second provides key information regarding the nomination process.

Models of galaxy formation in a hierarchical universe predict substantial scatter in the halo-to-halo stellar properties, owing to stochasticity in galaxies’ merger histories. Currently, only few detailed observations of galaxy’s halos are available, mainly for the Milky Way and M31. The Galaxy Halos, Outer disks, Substructure, Thick disks and Star clusters (GHOSTS) HST survey is the largest study to date of the resolved stellar populations in the outskirts of disk galaxies and its observations offer a direct test of model predictions. Here we present the results we obtain for six highly inclined nearby Milky Way-mass spiral galaxies. We find a great diversity in the properties of their stellar halos.

Coronal quasi-periodic fast-propagating (QFP) magnetosonic waves are scare in previous studies due to the relative low temporal and spatial resolution of past telescopes. Recently, they are detected by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). Here, two cases of QFP waves are presented. The analysis results indicate that QFP waves are tightly associated with the associated flares. It is indicate that QFP waves and the associated flares are possibly driven by the same physic process such as quasi-periodic magnetic reconnection process in producing flares.

I review some steps in the conversion of molecular cloud gas into stars and planets, with an emphasis in this presentation on the early stage molecular cloud fragmentation that leads to elongated filaments/ribbons. Magnetic fields can play a crucial role in all stages and need to be invoked particularly for early stage fragmentation as well as in late core collapse where it may control disk formation. I also review some elements of hydrodynamic modeling of disk evolution.

The inner few hundred parsecs of the Milky Way, the Central Molecular Zone (CMZ), is our closest laboratory for understanding star formation in the extreme environments (hot, dense, turbulent gas) that once dominated the universe. We present an update on the first large-area survey to expose the sites of star formation across the CMZ at high-resolution in submillimeter wavelengths: the CMZoom survey with the Submillimeter Array (SMA). We identify the locations of dense cores and search for signatures of embedded star formation. CMZoom is a three-year survey in its final year and is mapping out the highest column density regions of the CMZ in dust continuum and a variety of spectral lines around 1.3 mm. CMZoom combines SMA compact and subcompact configurations with single-dish data from BGPS and the APEX telescope, achieving an angular resolution of about 4″ (0.2 pc) and good image fidelity up to large spatial scales.

We present initial results from our study of the outer halo of the Milky Way using a large sample of RR Lyr(ab) variables datamined from the archives of the Palomar Transient Facility. Of the 464 RR Lyr in our sample with distances exceeding 50 kpc, 62 have been observed spectroscopically at the Keck Observatory. vr and σ(vr) are given as a function of distance between 50 and 110 kpc, and a very preliminary rather low total mass for the Milky Way out to 110 kpc of ~7±1.5×1011M⊙ is derived from our data.

The UV escape fraction, fescUV, is a key parameter determining the apparent SED of star forming galaxies. However, it is not well known how fescUV depends on the global geometry of dust distribution, nor how it evolves with time, although several models are proposed (e.g., Calzetti (2001)). We use ~130 normal star-forming galaxies (114 at z ~ 0 from Cortese et al. (2012) and 15 at z ~ 1–3 from Magnelli et al. (2012) and Saintonge et al. (2013)), to find that the z ~ 0 galaxies show a relatively tight anti-correlation between fescUV and surface dust mass density, Σd (See Fig. 1(a)). This correlation can be reproduced by a dust geometry model that well-mixed stars and dust follow the same exponential profile (Fig. 1(b)) with an effective mass-absorption coefficient κ(1600 Å) = 7.6+5.3−3.0 × 104 cm2 g−1, similar to the Milky Way value including absorption and scatter. The z ~ 1–3 galaxies are not inconsistent with this model. Our model can be easily implemented in semi-analytic models and cosmological hydrodynamics simulations (CHSs) of galaxy formation. Initial results for Shimizu et al. (2014)'s CHSs are presented.

IAU Commission 40 for Radio Astronomy (hereafter C40) brought together scientists and engineers who carry out observational and theoretical research in radio astronomy and who develop and operate the ground and space-based radio astronomy facilities and instrumentation. As of June 2015, the Commission had approximately 1,100 members from 49 countries, corresponding to nearly 10 per cent of the total IAU membership.

The cosmic web is a complex spatial pattern of walls, filaments, cluster nodes and underdense void regions. It emerged through gravitational amplification from the Gaussian primordial density field. Here we infer analytical expressions for the spatial statistics of caustics in the evolving large-scale mass distribution. In our analysis, following the quasi-linear Zel'dovich formalism and confined to the 1D and 2D situation, we compute number density and correlation properties of caustics in cosmic density fields that evolve from Gaussian primordial conditions. The analysis can be straightforwardly extended to the 3D situation. We moreover, are currently extending the approach to the non-linear regime of structure formation by including higher order Lagrangian approximations and Lagrangian effective field theory.

We present a set of time dependent chemical evolution models (based on the UMIST† astrochemistry 2012 code, McElroy et al. (2013) for a range of initial physical cloud parameters: 10 K < T < 20 K; 103 cm−3 < n(H2) < 5 ⋅ 104 cm−3; 1 < AV < 10 and with estimated values of scaled interstellar ultraviolet radiation field. We compare our chemical model results with the relative abundances of: CO, CH, OH, HCO+, HCN, HNC, NH3, N2H+ and H2CO molecules. We find significant time dependent variations of the chemical ratios of: X(NH3/H2); X(HCO+/H2) and X(HCO+/NH3). The input physical conditions were taken from Fehér O. et al. (2015) at 16 positions along the TMC-1 dark cloud. The NH3 and HCO+ relative densities based on the observations of Fehér O. et al. (2015) help to find the “chemical age” of the given position in the evolution curves.

By examining Herschel images in the HerMES & H-ATLAS surveys at the position of Planck Catalog of Compact Source sources we are able to determine the nature of the Planck sources. Most are simply nearby, known, dusty galaxies, while others are foreground galactic ‘cirrus’ dust. About 11% of sources, though, appear to be groups or clumps of fainter Herschel objects. Followup of a number of these indicates that they are galaxy clusters or protoclusters at z ~1-3 that contain a number of galaxies undergoing contemporaneous massive starbursts. These sources present challenges for current galaxy & cluster formation/evolution models.

The star formation rate in the Central Molecular Zone is an order of magnitude lower than in the disk of the Galaxy, given the amount of dense gas there. Understanding why star formation is different in this region is crucial if we are to understand the environmental dependence of star formation. Here, we present the detection of high-mass cores in the CMZ’s ‘dust ridge’ that have been discovered with the Submillimeter Array. These cores range in mass from ~ 50 – 1800 M⊙ within radii of 0.1 – 0.25 pc. All are young (pre-UCHII), meaning that they are prime candidates for representing the initial conditions of high-mass stars and sub-clusters. We compare these with high-mass cores and clouds in the Galactic disk and find that they are very similar in terms of their masses and sizes, despite being subjected to external pressures that are several magnitudes greater (~ 108 K cm−3). The fact that > 80% of these cores do not show any signs of star-forming activity in such a high-pressure environment leads us to conclude that this is further evidence of the critical density for star formation being heightened in the CMZ due to turbulence.

Two cases of filament oscillations induced by large-scale coronal shock waves are presented. For the first case, a chain of transverse oscillating filaments are observed in a proper order after the passing of a shock wave, and it is found that the they were triggered by the surface component of the dome-shaped shock wave. For the second case, simultaneous transverse oscillation of a limb prominence and longitudinal oscillation in an on-disk filament are launched by a single shock wave. It is found that the interaction angle between the shock wave and the prominence axis is the key to launch transverse or longitudinal filament oscillations. In addition, filament magnetic fields are estimated, using the measured parameters.

We show data from the SCUBA2 camera on JCMT, of molecular clouds. We focus on starless cores within the clouds. We present data of the Taurus region and show how the environment is affecting some cores' appearance in this region. We compare the SCUBA2 data with Herschel data and discuss the sensitivity of SCUBA2 to surface brightness in the sub-millimetre. We show how this leads to its ability to pick out the densest cores at a given temperature. Hence SCUBA2 preferentially picks out gravitationally bound pre-stellar cores. We discuss the effects of the magnetic field, and how this lends support to a model for the formation and evolution of cores in filamentary molecular clouds.

Since 2008 the IAU has worked with UNESCO and its advisory bodies to help recognise, promote and protect all types of astronomical heritage and to encourage nominations for World Heritage Sites relating to astronomy. I review the main challenges and achievements so far, and indicate how the Astronomy and World Heritage Initiative is likely to develop in the future.

This will be the last triennial report from Commission 50 under that label, because of the reorganization of the IAU at the end of the triennial period. Fortunately, site protection was recognized as an important ongoing function of the IAU, and the work of the Commission is continuing as Commission C.B7. The Commission has its primary association with Division B because of the technical aspects of its work and association with ground-based facilities, while it has the support of Division C as an Inter-Division Commission because of the strong need for educating the public on the issues.

This is a “biased” review because I will show recent evidence on the contribution of globular clusters (GCs) to the halo of our Galaxy seen through the lens of the new paradigm of multiple populations in GCs. I will show a few examples where the chemistry of multiple populations helps to answer hot questions including whether and how much GCs did contribute to the halo population, if we have evidence of the GCs-halo link, what are the strengths and weak points concerning this contribution.

We report a recent result of the FUGIN project, a Galactic plane CO survey using the Nobeyama 45-m Telescope and the FOREST receiver. In the third galactic quadrant, 42 square degrees are observed and 4752 molecular clouds are detected. Among them, 12 clouds are located at R (distance from the Galactic center) > 16 kpc. Molecular clouds at R < 16 kpc trace the Local, Perseus, and Outer arms.

We investigate large scale structure formation of collisionless dark matter in the phase space description based on the Vlasov-Poisson equation. We present the Schrödinger method, originally proposed by \cite{WK93} as numerical technique based on the Schrödinger Poisson equation, as an analytical tool which is superior to the common standard pressureless fluid model. Whereas the dust model fails and develops singularities at shell crossing the Schrödinger method encompasses multi-streaming and even virialization.

At local, galaxy properties are well known to be clearly different in different environments. However, it is still an open question how this environment-dependent trend has been shaped. We present the results of our investigation about the evolution of star-formation properties of galaxies over a wide redshift range, from z ~ 2 to z ~ 0.5, focusing its dependence on their stellar mass and environment (Lee et al. 2015). In the UKIDSS/UDS region, covering ~2800 square arcmin, we estimated photometric redshifts and stellar population properties, such as stellar masses and star-formation rates, using the deep optical and near-infrared data available in this field. Then, we identified galaxy cluster candidates within the given redshift range. Through the analysis and comparison of star-formation (SF) properties of galaxies in clusters and in field, we found interesting results regarding the evolution of SF properties of galaxies: (1) regardless of redshifts, stellar mass is a key parameter controlling quenching of star formation in galaxies; (2) At z < 1, environmental effects become important at quenching star formation regardless of stellar mass of galaxies; and (3) However, the result of the environmental quenching is prominent only for low mass galaxies (M* < 1010 M⊙) since the star formation in most of high mass galaxies are already quenched at z > 1.