The OCCASO survey targets intermediate-age and old OCs visible from the Northern hemisphere. OCCASO provides homogeneous radial velocities, atmospheric parameters, and individual abundances from high-resolution spectroscopy (R>65,000) of Red Clump stars. We present a first insight into the homogeneously analyzed chemical abundances obtained fror 18 Northern OCs from OCCASO data. Our sample includes an interesting inner disk OC, NGC 6705, analyzed in the literature with inconclusive results about its α abundances. From OCCASO data this is an α-enhanced OC from the analysis of Si, Ca, Ti, Mg and O, despite its young age.

We used our detailed analytic local disc model to compare predictions in number counts, colour distribuitons and kinematics with a data set extracted from a combination of TGAS and RAVE catalogues. We find generally a very good agreement with some deviations close to the Galactic plane.

We describe the dynamical behavior of isolated old ( ⩾ 1Gyr) objects-like Neutron Stars (NSs). These objects are evolved under smooth, time-independent, gravitational potentials, axisymmetric and with a triaxial dark halo. We analysed the geometry of the dynamics and applied the Poincaré section for comparing the influence of different birth velocities. The inspection of the maximal asymptotic Lyapunov (λ) exponent shows that dynamical behaviors of the selected orbits are nearly the same as the regular orbits with 2-DOF, both in axisymmetric and triaxial when (ϕ, qz )= (0,0). Conversely, a few chaotic trajectories are found with a rotated triaxial halo when (ϕ, qz )= (90, 1.5). The tube orbits preserve direction of their circulation around either the long or short axis as appeared in the triaxial potential, even when every initial condition leads to different orientations. The Poincaré section shows that there are 2-D invariant tori and invariant curves (islands) around stable periodic orbits that bound to the surface of 3-D tori. The regularity of several prototypical orbits offer the means to identify the phase-space regions with localized motions and to determine their environment in different models, because they can occupy significant parts of phase-space depending on the potential. This is of particular importance in Galactic Dynamics.

This optical catalogue combines the all-sky USNO-B1.0/A1.0 and most-sky APM catalogues, plus overlays of SDSS optical data, into a single all-sky map presented in a sparse binary format that is easily downloaded at 9 Gb zipped. Total count is 1 163 237 190 sources and each has J2000 astrometry, red and blue magnitudes with PSFs and variability indicator, and flags for proper motion, epoch, and source survey and catalogue for each of the photometry and astrometry. The catalogue is available on http://quasars.org/asp.html, and additional data for this paper is available at http://dx.doi.org/10.4225/50/5807fbc12595f.

By applying a display ecology to the Deeper, Wider, Faster proactive, simultaneous telescope observing campaign, we have shown a dramatic reduction in the time taken to inspect DECam CCD images for potential transient candidates and to produce time-critical triggers to standby telescopes. We also show how facilitating rapid corroboration of potential candidates and the exclusion of non-candidates improves the accuracy of detection; and establish that a practical and enjoyable workspace can improve the experience of an otherwise taxing task for astronomers. We provide a critical road test of two advanced displays in a research context—a rare opportunity to demonstrate how they can be used rather than simply discuss how they might be used to accelerate discovery.

Since the beginning of the new millennium, more than 100 z ~ 6 quasars have been discovered through several surveys and followed-up with multi-wavelength observations. These data provided a large amounts of information on the growth of supermassive black holes at the early epochs, the properties of quasar host galaxies and the joint formation and evolution of these massive systems. We review the properties of the highest z quasars known so far, especially focussing on some of the most recent results obtained in (sub-)millimetre bands. We discuss key observational challenges and open issues in theoretical models and highlight possible new strategies to improve our understanding of the galaxy black hole formation and evolution in the early Universe.

Using images from the SDSS DR13 library, we examine the structural properties of 374 bright (classed E0 to E6) and dwarf ellipticals [classed dE(nN) to dE(N)]. The sample combines a multicolour sample of bright ellipticals (252 galaxies with $M_{\text{g}} < -20$ ) with a new sample of faint ellipticals (60 galaxies with $M_{\text{g}} > -20$ ) which overlaps the dwarf elliptical sample (62 galaxies) in luminosity and size. The faint ellipticals extend the linear structural correlations found for bright ellipticals into parameter space not occupied by dwarf ellipticals indicating a dichotomy exists between the two types. In particular, many faint ellipticals have significantly higher effective surface brightnesses compared to dwarf ellipticals which eliminates any connection at a set stellar mass. Template analysis of the three subsets of ellipticals demonstrates that the bright and faint ellipticals follow the same trends of profile shape (weak homology), but that dwarf ellipticals form a separate and distinct structural class with lower central surface brightnesses and extended isophotal radii.

We present low-frequency spectral energy distributions of 60 known radio pulsars observed with the Murchison Widefield Array telescope. We searched the GaLactic and Extragalactic All-sky Murchison Widefield Array survey images for 200-MHz continuum radio emission at the position of all pulsars in the Australia Telescope National Facility (ATNF) pulsar catalogue. For the 60 confirmed detections, we have measured flux densities in 20 × 8 MHz bands between 72 and 231 MHz. We compare our results to existing measurements and show that the Murchison Widefield Array flux densities are in good agreement.

We present results from a multiwavelength study of the blazar PKS 1954–388 at radio, UV, X-ray, and gamma-ray energies. A RadioAstron observation at 1.66 GHz in June 2012 resulted in the detection of interferometric fringes on baselines of 6.2 Earth-diameters. This suggests a source frame brightness temperature of greater than 2 × 1012 K, well in excess of both equipartition and inverse Compton limits and implying the existence of Doppler boosting in the core. An 8.4-GHz TANAMI VLBI image, made less than a month after the RadioAstron observations, is consistent with a previously reported superluminal motion for a jet component. Flux density monitoring with the Australia Telescope Compact Array confirms previous evidence for long-term variability that increases with observing frequency. A search for more rapid variability revealed no evidence for significant day-scale flux density variation. The ATCA light-curve reveals a strong radio flare beginning in late 2013, which peaks higher, and earlier, at higher frequencies. Comparison with the Fermi gamma-ray light-curve indicates this followed ~ 9 months after the start of a prolonged gamma-ray high-state—a radio lag comparable to that seen in other blazars. The multiwavelength data are combined to derive a Spectral Energy Distribution, which is fitted by a one-zone synchrotron-self-Compton (SSC) model with the addition of external Compton (EC) emission.

We present observations of thermonuclear (type-I) X-ray bursts, selected for comparison with numerical models. We provide examples of four distinct cases of ignition: He-ignition in mixed H/He fuel (case 1); He-ignition in pure He fuel, following exhaustion of accreted H by steady burning (case 2); ignition in (almost) pure He accumulated from an evolved donor in an ultracompact system; and a superburst, thought to arise from ignition of carbon fuel produced as a by-product of H/He bursts. For regular bursts, we measured the recurrence time and calculated averaged burst profiles from RXTE observations. We also estimated the recurrence time for pairs of bursts, including those observed during a transient outburst, modelled using a numerical ignition code. For each example we list the burst properties including recurrence time, fluence, peak flux, the persistent flux level (and inferred accretion rate), and the ratio of persistent flux to fluence. In the accompanying material, we provide a bolometric lightcurve for each burst, determined from time-resolved spectral analysis. Along with the inferred or adopted parameters for each burst system, including distance, surface gravity, and redshift, these data are suggested as suitable test cases for ignition models.

Analysis of solar magnetic fields using observations as well as theoretical interpretations of the scattering polarisation is commonly designated as a high priority area of the solar research. The interpretation of the observed polarisation raises a serious theoretical challenge to the researchers involved in this field. In fact, realistic interpretations need detailed investigations of the depolarising collisions.

The goal of this paper is to determine new relationships which allow the calculation of any collisional rates of the d-levels of ions by simply determining the value of n* and E p without the need of determining treating the collisional problem.

In this work, we applied our collisional code to a large number of cases involving complex and simple ions. After that, the results are injected in a genetic programming code in order to infer original relationships which will be of great help to solar applications. We discussed the accuracy of our collisional rates in the cases of complex atoms and atoms with hyperfine structure.

We compared the results obtained through the new relationships with the results obtained directly by running our code of collisions. The percentage of error is about 10% in the average value.

We present spectroscopic and photometric analysis of the eclipsing binary KIC 7385478. We find that the system is formed by F1V + K4III–IV components. Combining results from analysis of spectroscopic data and Kepler photometry, we calculate masses and radii of the primary and the secondary components as M 1 = 1.71 ± 0.08 M⊙, M 2 = 0.37 ± 0.04 M⊙ and R 1 = 1.59 ± 0.03 R⊙, R 2 = 1.90 ± 0.03 R⊙, respectively. Position of the primary component in HR diagram is in the region of γ Doradus type pulsators and residuals from light curve modelling exhibit additional light variation with a dominant period of ~ 0.5 d. These are clear evidences of the γ Doradus type pulsations on the primary component. We also observe occasional increase in amplitude of the residuals, where the orbital period becomes the most dominant period. These may be attributed to the cool star activity originating from the secondary component.

We study a possibility to detect signatures of brown dwarf companions in a circumstellar disc based on spectral energy distributions. We present the results of spectral energy distribution simulations for a system with a 0.8 M⊙ central object and a companion with a mass of 30 M J embedded in a typical protoplanetary disc. We use a solution to the one-dimensional radiative transfer equation to calculate the protoplanetary disc flux density and assume, that the companion moves along a circular orbit and clears a gap. The width of the gap is assumed to be the diameter of the brown dwarf Hill sphere. Our modelling shows that the presence of such a gap can initiate an additional minimum in the spectral energy distribution profile of a protoplanetary disc at λ = 10–100 μm. We found that it is possible to detect signatures of the companion when it is located within 10 AU, even when it is as small as 3 M J. The spectral energy distribution of a protostellar disc with a massive fragment (of relatively cold temperature ~400 K) might have a similar double peaked profile to the spectral energy distribution of a more evolved disc that contains a gap.

Small-JASMINE (hearafter SJ), infrared astrometric satellite, will measure the positions and the proper motions which are located around the Galactic center, by operating at near infrared wave-lengths. SJ will clarify the formation process of the super massive black hole (hearafter SMBH) at the Galactic center. In particular, SJ will determine whether the SMBH was formed by a sequential merging of multiple black holes. The clarification of this formation process of the SMBH will contribute to a better understanding of merging process of satellite galaxies into the Galaxy, which is suggested by the standard galaxy formation scenario. A numerical simulation (Tanikawa and Umemura, 2014) suggests that if the SMBH was formed by the merging process, then the dynamical friction caused by the black holes have influenced the phase space distribution of stars. The phase space distribution measured by SJ will make it possible to determine the occurrences of the merging process.

We developed a Bayesian framework to determine in a robust way the relation between velocity dispersions and chemical abundances in a sample of stars. Our modelling takes into account the uncertainties in the chemical and kinematic properties. We make use of RAVE DR5 radial velocities and abundances together with Gaia DR1 proper motions and parallaxes (when possible, otherwise UCAC4 data is used). We found that, in general, the velocity dispersions increase with decreasing [Fe/H] and increasing [Mg/Fe]. A possible decrease in velocity dispersion for stars with high [Mg/Fe] is a property of a negligible fraction of stars and hardly a robust result. At low [Fe/H] and high [Mg/Fe] the sample is incomplete, affected by biases, and likely not representative of the underlying stellar population.

The detection of thousands of planets orbiting stars other than the Sun has shown that planets are common throughout the Galaxy. However, the diversity of systems found has also raised many questions regarding the process of planet formation and evolution. Interestingly, but perhaps not unexpectedly, crucial information to constraint the planet formation models comes from the analysis of the planet-host stars. In this talk I will review why it is so important to study and understand the stars when finding and characterising exoplanets. I will then present some of the most relevant star-planet relations found to date, and how they are helping us to understand planet formation and evolution. I will end with a presentation of the future steps in this field, including what Gaia will bring to help constrain the properties of planet-host stars, as well as to the star-planet connection.

We study the abundance of the remnants of stars that reionized the Universe in galaxies in the present day Universe using the eagle cosmological hydrodynamical simulation. High mass galaxies contain most of these ‘reionizers’. The fractional number of galaxies that do not host reionizers increases with decreasing stellar mass, M ⋆. For the galaxies that host reionizers, the fraction of mass of the galaxy in reionizers increases with decreasing M ⋆, such that the fraction is low (~10−4) for high mass galaxies and can be as high as 0.1 in low mass galaxies, M ⋆ ≤ 107 M⊙. In Milky-Way like galaxies, the distribution of reionizers is spatially more extended than that of normal stars.

I summarize two recent projects involving the Gaia-TGAS data. Firstly, I discuss a detection of a lack of disc stars in the Solar neighbourhood with velocities close to zero angular momentum. We use predictions of this effect to make a measurement of the Solar rotation velocity around the Galactic centre, and also of R 0. Secondly, I discuss a detection of a group of stars with systematically high Galactic rotation velocity. We propose that it may be caused by the Perseus arm and compare the data with simulations.

Angle/action based distribution function (DF) models can be optimised based on how well they reproduce observations thus revealing the current matter distribution in the Milky Way. Gaia data combined with data from other surveys, e.g. the RAVE/TGAS sample, and its full selection function will greatly improve their accuracy.