The standard paradigm of structure formation in the universe, the cold dark matter cosmology, contains several crucial unsolved problems such as “cusp-core problem” and “too-big-to-fail problem”. To solve these problems, we study about the dynamical response of a virialized system with a central cusp to the energy feedback driven by periodic supernova feedback using collisionless N-body simulations with the Nested-Particle-Mesh code. The resonance between dark matter particles and the density wave excited by the oscillating potential plays a significant role in the cusp-core transition of dark matter halos. Furthermore, we show that the cusp-core transition with periodic supernova feedback can solve the too-big-to-fail problem.

We investigate the sputtering and thermal desorption of various grain-surface species in one dimensional steady-state shock models motivated by the recent detection of SO emission towards class 0-I protostars. We find that the thermal desorption is more efficient at higher densities, while the efficiency of sputtering is independent of density. SO is completely desorbed, if the accretion velocity is higher than ~ 2 km s−1 and ~ 4 km s−1, with the pre-shock density of 109 cm−3 and 108 cm−3, respectively. The column density of warm post-shock gas is found to be N ~ 1021 cm−2. If the abundance of SO ice is ~ 10−7 relative to hydrogen in the pre-shock material, SO emission around L1527 can be explained by the sublimation at the accretion shock.

The construction of viable and physically-realistic interstellar dust models is only possible if the constraints imposed by laboratory data on interstellar dust analogue materials are respected and used within a meaningful theoretical framework. These “physical” dust models can then be directly compared to observations without the need for any tuning to fit the observations. Such models will generally fail to achieve the excellent fits to observations that “empirical” models are able to achieve. However, the physically-realistic approach will necessarily lead to a deeper insight and a fuller understanding of the nature and evolution of interstellar dust. The THEMIS modelling approach, based on (hydrogenated) amorphous carbons and amorphous silicates with metallic Fe and/or FeS nano-inclusions appears to be a promising move in this direction.

To better understand the differences between coronal cloud prominences and channel prominences, we systematically identified and analyzed coronal cloud prominences recorded in SDO/AIA images at 304 Å from 2010 May 20 through 2012 April 28. For the 225 cases identified, their numbers vary directly with the sunspot number. Their durations are typically less than 3 days. Their most frequent maximum height is 90,000 + and - 10,000 km. We offer our hypothesis that many coronal cloud prominences originate from some of the mass of previously erupted filaments ejected high out of their filament channels; subsequently part of this mass falls and collects in leaky magnetic troughs among coronal magnetic fields which constrain the leaked mass to slowly drain downward along curved trajectories where it appears as coronal rain. Currently there is inadequate evidence for a convincing correspondence between either coronal cloud prominences or channel prominences with stellar prominences detected to date.

The number of confirmed, high-redshift galaxy clusters is very low compared to the number of well-studied clusters nearby. Bent, double-lobed radio sources are frequently found in galaxy clusters, and thus can be used as tracers for efficiently locating high-redshift clusters. Using our Spitzer Snapshot Survey, we have identified approximately 300 potential new clusters with redshifts 0.7 < z < 3. These objects make up the high-redshift portion of the Cluster Occupied by Bent Radio AGN (COBRA) survey. We have created color-magnitude diagrams using infrared and optical data. Using the colors of the radio source host and the red sequence we can estimate redshifts for our clusters, as well as examine the evolution of the cluster galaxies over a large range of cosmic time.

Colliding plasmas are ubiquitous in astrophysical environments and allow conversion of kinetic energy into heat and, most importantly, the acceleration of particles to extremely high energies to form the cosmic ray spectrum. In collisionless astrophysical plasmas, kinetic plasma processes govern the interaction and particle acceleration processes, including shock formation, self-generation of magnetic fields by kinetic plasma instabilities, and magnetic field compression and reconnection. How each of these contribute to the observed spectra of cosmic rays is not fully understood, in particular both shock acceleration processes and magnetic reconnection have been proposed. We will review recent results of laboratory astrophysics experiments conducted at high-power, inertial-fusion-class laser facilities, which have uncovered significant results relevant to these processes. Recent experiments have now observed the long-sought Weibel instability between two interpenetrating high temperature plasma plumes, which has been proposed to generate the magnetic field necessary for shock formation in unmagnetized regimes. Secondly, magnetic reconnection has been studied in systems of colliding plasmas using either self-generated magnetic fields or externally applied magnetic fields, and show extremely fast reconnection rates, indicating fast destruction of magnetic energy and further possibilities to accelerate particles. Finally, we highlight kinetic plasma simulations, which have proven to be essential tools in the design and interpretation of these experiments.

Commission 45 is solidly anchored in the beginnings of the IAU. It evolved out of Commission 29, which was one of the original commissions and whose title and emphasis was the Spectral Classification of Stars (Transactions of the IAU, Volume I, 1922). C29 was formed with W.S. Adams (Pasadena) as president. Its first members were Miss Cannon, R.H. Curtiss, A. Fowler, A. de Gramont, M. Hamy, H.F. Newall, J.S. Plaskett, H.N. Russell, all very much part of the history of stellar spectroscopy. In the 1922 Transactions report it was recognized the Harvard System of spectral classification “has already been adopted by international agreement. . .”

Asteroseismology is among the most powerful observational tools to determine fundamental properties of stars. Space-based photometry has recently enabled the systematic detection of oscillations in exoplanet host stars, allowing a combination of asteroseismology with transit and radial-velocity measurements to characterize planetary systems. In this contribution I will review the key synergies between asteroseismology and exoplanet science such as the precise determination of radii and ages of exoplanet host stars, as well as applications of asteroseismology to measure spin-orbit inclinations in multiplanet systems and orbital eccentricities of small planets. Finally I will give a brief outlook on asteroseismic studies of exoplanet hosts with current and future space-based missions such as K2 and TESS.

We still do not know the timescale for the merging of binary black holes (BHs). This timescale has important implications for gravitational wave predictions and our understanding of BH demographics. Here we discuss efforts to constrain the fraction of BH pairs on kpc scales using observations of dual active galactic nuclei.

We report on the most recent progresses on the modelling of the asymptotic giant branch (AGB) phase. We show that dust formation in the wind of AGBs is sensitive to the mass of the precursor, low–mass AGB with mass below ~ 3 M ⊙ producing mainly carbonaceous dust, whereas their counterparts of higher mass produce silicates and alumina dust. We discuss the uncertainty of the results, due to the poor knowledge of physical mechanisms highly important for AGB evolution, primarily convection and mass loss. We show how the chemical composition of planetary nebulae can be used to draw information on the main features of AGB evolution.

Cosmological simulations predict that dark matter halos with circular velocities lower than 30 km/s should have lost most of their neutral gas by heating of the ultra-violet background. This is in stark contrast with gas-rich galaxies such as e.g. Leo T, Leo P and Pisces A, which all have circular velocities of ~15 km/s (Ryan-Weber et al. 2008, Bernstein-Cooper et al. 2014, Tollerud et al. 2015). We show that when we include feedback from the first stars into our models, simulated dwarfs have very different properties at redshift 0 than when this form of feedback is not included. Including this Population-III feedback leads to galaxies that lie on the baryonic Tully-Fisher relation over the entire mass range of star forming dwarf galaxies, as well as reproducing a broad range of other observational properties.

Activities started in early 2015. Individuals applying for nomination for IAU Individual Membership should have contacted their NCA or Adhering Organization before December 1, 2014. The deadline for approved nominations for Individual Members to be submitted to the IAU Secretariat by NCAs or Adhering Organizations was February 3, 2015. Therefore, the focus of this report are the last months prior to the IAU XXIX General Assembly (August 2015) in Honolulu.

We discuss an overall picture of star formation in the Galaxy. Recent high-resolution magneto-hydrodynamical simulations of two-fluid dynamics with cooling/heating and thermal conduction have shown that the formation of molecular clouds requires multiple episodes of supersonic compression. This finding enables us to create a new scenario of molecular cloud formation through interacting shells or bubbles on galactic scales. We estimate the ensemble-averaged growth rate of individual molecular clouds, and predict the associated cloud mass function. This picture naturally explains the accelerated star formation over many million years that was previously reported by stellar age determination in nearby star forming regions. The recent claim of cloud-cloud collisions as a mechanism for forming massive stars and star clusters can be naturally accommodated in this scenario. This explains why massive stars formed in cloud-cloud collisions follows the power-law slope of the mass function of molecular cloud cores repeatedly found in low-mass star forming regions.

Long gamma-ray bursts (LGRBs) are associated to the deaths of massive stars and could thus be used as a potentially powerful tool to trace cosmic star formation. However the conditions needed to produce a LGRBs may introduce a bias in the LGRB rate versus star formation rate (SFR) relation (called LGRB efficiency hereafter).

We have undertaken a study of the properties of the host galaxies of the BAT6 complete sample of LGRB to improve our knowledge on the LGRB efficiency, its redshift evolution, and the factor affecting it. This is the base to properly use LGRBs as SFR tracers.

We show that at z < 1 LGRBs are not direct SFR tracers because they tend to avoid high-metallicity galaxies. The use of the BAT6 complete sample keeps this result from being affected by possible biases that could have influenced past results based on incomplete samples. The preference for low (but not extremely low) metallicities can be a consequence of the particular conditions needed for the progenitor star to produce a GRB.

Los Alamos National Laboratory has calculated a new generation of radiative opacities (OPLIB data using the ATOMIC code) for elements with atomic number Z = 1-30 with improved physics input, updated atomic data, and finer temperature grid to replace the Los Alamos LEDCOP opacities released in the year 2000. We calculate the evolution of standard solar models including these new opacities, and compare with models evolved using the Lawrence Livermore National Laboratory OPAL opacities (Iglesias & Rogers 1996). We use the solar abundance mixture of Asplund et al. 2009. The Los Alamos ATOMIC opacities (Colgan et al. 2013a, 2013b, 2015) have steeper opacity derivatives than those of OPAL for temperatures and densities of the solar interior radiative zone. We compare the calculated nonadiabatic solar oscillation frequencies and solar interior sound speed to observed frequencies and helioseismic inferences. The calculated sound-speed profiles are similar for models evolved using either the updated Iben evolution code (see Guzik & Mussack 2010), or the MESA evolution code (Paxton et al. 2015). The LANL ATOMIC opacities partially mitigate the ‘solar abundance problem’.

We present the current status of the spectroscopic follow-up of a large number of RR Lyrae (RRL) halo overdensity candidates recently found by Torrealba et al. (2015) using southern-hemisphere data from the Catalina Real-time Transient Survey (CRTS). Characterizing the individual RRL stars in these overdensities is crucial to confirm them as real halo substructures. Low-resolution spectra have been obtained for RRL stars in 11 different overdensities, using the SOAR and Magellan telescopes. Radial velocities and metallicities have been derived so far for 123 and 99 RRL stars, respectively.

Here, we present a set of time-dependent 3D RMHD simulations of a M-dwarf star representative of AD Leo, which extend from the upper convection zone into the chromosphere. The 3D model atmospheres are characterized by a very dynamic and intermittent structure on small spatial and temporal scales and a wealth of physical processes, which by nature cannot be described by means of 1D static model atmospheres. Artificial observations of these models imply that a combination of complementary diagnostics such as Ca II lines and the continuum intensity from UV to millimeter wavelengths, probe various properties of the dynamics, thermal and magnetic structure of the photosphere and the chromosphere and thus provide measures of stellar activity, which can be compared to observations. The complicated magnetic field structure and its imprint in synthetic diagnostics may have important implications for the understanding and characterization of stellar activity and with it possibly for the evaluation of planetary habitability around active M-dwarf stars.

Task Force 3 is focused on public outreach. A number of projects have been funded by the OAD in the past, and in this meeting, the opportunity was provided for both funded projects as well as other non-funded projects with similar objectives.Three projects were presented during the session which sparked discussion in this area.The following outlines the talks.