We have completed a kinematical analysis of 184 selected Planck Galactic Cold Clumps (PGCC) (Planck Collaboration, 2015) in order to understand better the stability of molecular clouds and the induced star formations. Most of our clumps are in the second quadrant of the Galaxy. For the investigation we used 12CO, 13CO, C18O line observations which covered the 184 PGCC fully or partially. The majority of the data were observed with the Osaka 1.85 m telescope in Japan (Nishimura et al. 2015) and we also have some observations with the KOSMA 3 m telescope, from Switzerland (Kramer et al. 2000) and with the IRAM 30 m telescope, Spain (www.iram-institute.org).

A science meeting is an opportunity to exchange ideas with colleagues, to hear of new results and to learn from comprehensive reviews of a topic. Much of it happens in the meeting room and much of it also happens in the corridors of the meeting venue and in restaurants and perhaps bars near the meeting location. Its a combination of people and of place that is a bit [hard to predict] but when it goes well, you know it.

All these elements came together for IAU Focus Meeting 6, X-ray Surveys of the Hot and Energetic Cosmos, in Honolulu last August. There are not many places more pleasant for an astronomical meeting than Hawaii, and the speakers did an outstanding job of reviewing the field and relaying the latest results.

X-ray surveys have been a staple of astrophysics for nearly 50 years. There are large surveys and small, deep surveys and shallow, soft X-ray energies and hard. The combination gives us invaluable information about the hottest and/or most relativistic environments known. Theory helps us interpret the data in terms of the underlying physics. The heady combination of all of the above shaken and mixed in Hawaiian paradise has given us all a deeper understanding of the Universe. Please read on to see why.

Recent advances in X-ray and microwave observations have provided unprecedented insights into the structure and evolution of the hot X-ray emitting plasma from their cores to the virialization region in outskirts of galaxy clusters. Recent Sunyaev-Zel'dovich (SZ) surveys (ACT, Planck, SPT) have provided new cluster catalogs, significantly expanding coverage of the mass-redshift plane, while Chandra and XMM-Newton X-ray follow-up programs have improved our understanding of cluster physics and evolution as well as the surveys themselves. However, the current cluster-based cosmological constraints are still limited by uncertainties in cluster astrophysics. In order to exploit the statistical power of the current and upcoming X-ray and microwave cluster surveys, it is critical to improve our understanding of the structure and evolution of the hot X-ray emitting intracluster medium (ICM). In this session, we discussed recent advances in observations and simulations of galaxy clusters, with highlights on (i) the evolution of ICM profiles and scaling relations, (ii) physical processes operating in the outskirts of galaxy clusters, and (iii) impact of mergers on the ICM structure in groups and clusters.

We discuss recent advances and prospects in our understanding of the formation of structures on cosmic scales based on surveys of galaxy clusters in the X-ray bands. We highlight the interaction between observations and numerical simulations of the X-ray sky. We show how future surveys will unveil the nature of the dark energy and study its evolution with time.

The combined catalogue of AGN selected from optical identifications of X-ray sources based on Hamburg–ROSAT and Byurakan–Hamburg–ROSAT catalogues is a homogeneous sample for statistical studies. Optically identified X-ray sources from ROSAT BSC and FSC are included, 4253 X-ray selected AGN in total. We carried out classification for 210 of these candidate sources based on available SDSS spectra and enlarged the sample of confirmed AGN. Statistical investigations of the sample were also carried out. Multiwavelength SEDs have also been constructed to link them to classifications.

We report recent investigations in the field of Early Black Holes. We summarize recent theoretical and observational efforts to understand how Black Holes formed and eventually evolved into Super Massive Black Holes at high-z. This paper makes use of state of the art computer simulations and multiwavelength surveys. Although non conclusive, we present results and hypothesis that pose exciting challenges to modern astrophysics and to future facilities.

Focus Meeting 6 of the IAU 2015 Symposium centered around the topic of “X-ray Surveys of the Hot and Energetic Universe.” Within this two-day meeting seven sessions (31 total talks) were presented, whose topics included galaxy cluster physics and evolution, cluster cosmological studies, AGN demographics and X-ray binary populations, first quasars, accretion and feedback, large-scale structures, and normal and starburst galaxies. Herein, I summarize the results presented during session #5, which focused on AGN accretion and feedback. Six authors contributed their work to our session: Laura Brenneman, Kazushi Iwasawa, Massimo Gaspari, Michaela Hirschmann, Franz Bauer and Yuan Liu. I provide a brief introduction below, followed by the details of the presentations of each author in the order in which the presentations were given.

Our understanding of the cosmic evolution of supermassive black holes (SMBHs) has been revolutionized by the advent of large multiwavelength extragalactic surveys, which have enabled detailed statistical studies of the host galaxies and large-scale structures of active galactic nuclei (AGN). We give an overview of some recent results on SMBH evolution, including the connection between AGN activity and star formation in galaxies, the role of galaxy mergers in fueling AGN activity, the nature of luminous obscured AGN, and the connection between AGN and their host dark matter halos. We conclude by looking to the future of large-scale extragalactic X-ray and spectroscopic surveys.

X-ray surveys of normal galaxies, i.e. those that do not host actively supermassive black holes, have revealed important information on the nature of accreting stellar-mass compact objects (neutron stars and black holes), constraints on populations of possible intermediate-mass black holes (102–5M⊙), and on the reservoir of materials in the hot interstellar medium of the most massive galaxies. Here we summarize briefly the results of Chandra and NuSTAR surveys of several samples of galaxies covered during the 2015 IAU General Assembly. This includes a comprehensive study of six nearby starburst galaxies by the NuSTAR mission, of high-redshift galaxies from the 6 Ms Chandra Deep Field South for which evolutionary trends in X-ray emission over cosmic time have been measured, of collisional ring galaxies which are excellent local environments for studying intermediate-mass black holes and of elliptical galaxies which are ideal for study of the hot gas reservoirs containing the effects of stellar and AGN feedback.

A 3-day Focus Meeting entitled “Stellar Physics in Galaxies throughout the Universe” was held during the IAU XXIX General Assembly. The meeting brought together astrophysicists from the stellar physics, extragalactic astrophysics and cosmology communities to discuss how current and future results can foster progress in these disjoint science areas. Areas covered include stellar evolution of single and binary stars from the zero-age main-sequence to the terminal stage, the feedback of stars to the interstellar medium via radiation, dust production and chemical enrichment, and the properties of the most massive stars and of cosmologically significant stellar phases such as AGB and Wolf-Rayet stars. The limitations of our understanding of the physics of local stars and their effects on, e.g., ages, chemical composition and the initial mass function of galaxies at low to high redshift were evaluated.

We discuss how the nuclear path of the CNO cycles in massive stars can be employed as a quality indicator for model atmosphere analyses and for the derivation of tight observational constraints for developing a better understanding of the evolution of rotating massive stars.

We present a new database of alpha enhanced evolutionary tracks and isochrones, computed with PARSEC (the PAdova & TRieste Stellar Evolution Code). The new isochrones are tested against Color-Magnitude Diagrams of well studied Globular Clusters, tacking into account multiple population effects. They are also compared with observations of dwarf stars in the Solar vicinity. After these preliminary computations, we will provide the full sets of isochrones with chemical compositions suitable for Globular Clusters and Bulge stars, that will be fully implemented into galaxy simulators. We will also provide new models suitable for the analysis of unresolved stellar populations in early type galaxies.

In this talk I present the latest results of the ESTER project that has taken up the challenge of building two dimensional (axisymmetric) models of stars rotating at any rotation rate. In particular, I focus on main sequence massive and intermediate mass stars. I show what should be expected in such stars as far as the differential rotation and the associated meridional circulation are concerned, notably the emergence of a Stewartson layer along the tangent cylinder of the core. I also indicate what may be inferred about the evolution of an intermediate-mass star at constant angular momentum and how Be stars may form. I finally give some comparisons between models and observations of the gravity darkening on some nearby fast rotators as it has been derived from interferometric observations. In passing, I also discuss how 2D models can help to recover the fundamental parameters of a star.

We present early results from a detailed analysis of the BSS population in Galactic GCs based on HST data. Using proper motion cleaning of the color-magnitude diagrams we construct a large catalog of BSSs and study some population properties. Stellar evolutionary models are used to find stellar mass and age estimates for the BSS populations in order to establish constraints related to the dynamical interactions in which they may have formed.

In this contribution, I present the results of a differential analysis of CH spectral lines for the determination of carbon abundances with three- and one-dimensional model atmospheres of late-type stars at various metallicities. 3D-1D abundance corrections are found to be significant particularly at low metallicities and for turn-off stars. The dependence of 3D-1D carbon abundance corrections on the stellar C/O ratio is also discussed.

Stellar convection is customarily described by the mixing-length theory, which makes use of the mixing-length scale to express the convective flux, velocity, and temperature gradients of the convective elements and stellar medium. The mixing-length scale is taken to be proportional to the local pressure scale height, and the proportionality factor (the mixing-length parameter) must be determined by comparing the stellar models to some calibrator, usually the Sun. No strong arguments exist to suggest that the mixing-length parameter is the same in all stars and all evolutionary phases. Because of this, all stellar models in the literature are hampered by this basic uncertainty.

In a recent paper (Pasetto et al. 2014) we presented a new theory that does not require the mixing length parameter. Our self-consistent analytical formulation of stellar convection determines all the properties of stellar convection as a function of the physical behavior of the convective elements themselves and the surrounding medium. The new theory of stellar convection is formulated starting from a conventional solution of the Navier-Stokes/Euler equations, i.e. the Bernoulli equation for a perfect fluid, but expressed in a non-inertial reference frame co-moving with the convective elements. In our formalism, the motion of stellar convective cells inside convective-unstable layers is fully determined by a new system of equations for convection in a non-local and time-dependent formalism.

We obtained an analytical, non-local, time-dependent solution for the convective energy transport that does not depend on any free parameter. The predictions of the new theory are compared with those from the standard mixing-length paradigm with positive results for atmosphere models of the Sun and all the stars in the Hertzsprung-Russell diagram.

Stellar evolution can nowadays be modelled with a high degree of accuracy and completeness up to the most advanced stages. However in spite of the progresses, complex physical processes exist that still suffer of large uncertainties even in the most placid evolutionary phases. The straightforward drawback is that models lose their predictive power and this is particularly critical for stellar population synthesis. Here I will focus on one of such processes, convective mixing, and briefly review potentially helpful observational tests to decipher its efficiency during the main nuclear burning phases of intermediate mass stars.

A large fraction of extremely metal-poor halo stars are strongly enriched in carbon (CEMP stars). The standard scenario for their origin is mass transfer in binary systems, but this assumes that they are binaries. If not, the C must have been implanted in their natal clouds from a distant production site(s) in the preceding - possibly first - generation of stars. The binary population of CEMP subgroups can shed light on these processes.

We compare in a systematic way spectrometric, photometric and mid-infrared (VLTI/MIDI) interferometric measurements with different types of model atmospheres. Self-consistent dynamic model atmospheres in particular were used to interpret in a consistent way the dynamic behavior of gas and dust. The results underline how the joint use of different kind of observations, as photometry, spectroscopy and interferometry, is essential to understand the atmospheres of pulsating C-rich AGB stars. The sample of C-rich stars discussed in this work provides crucial constraints for the atmospheric structure.

Stellar yields are an essential tool for studies of chemical evolution. For low and intermediate-mass stars (0.8 up to 8-10M⊙) the richest nucleosynthesis occurs when the stars are on the asymptotic giant branch (AGB) of stellar evolution. We discuss the main nucleosynthesis outcomes, along with the uncertainties that affect the theoretical calculations. The uncertainties in the physics can be improved by comparing theoretical models to observations, including chemically peculiar metal-poor stars, along with AGB stars and their progeny.