The striking similarity between the cyclic equatorward migration of the torsional oscillation belts and the sunspot activity latitudes inspired several attempts to seek an explanation of the torsional phenomenon in terms of interactions between flux ropes and plasma motions. The aim of the present work is to examine the spatial and temporal coincidences of the torsional waves and the emergence of sunspot magnetic fields. The locations of the shearing latitudes have been compared with the distributions of certain sunspot parameters by using sunspot data of more than two cycles. The bulges of the sunspot number and area distributions tend to be located within the ‘forward’ belts close to their poleward shearing borders. A possible geometry of the magnetic and velocity field interacion is proposed.

3D global MHD simulations of magneto-driven turbulence are performed for the disk of 100 AU with reduced amount of 10μm fluffy dust grains. We use X-ray and cosmic ray ionization, as well as simplified treatment of recombination on dust grains. The ionization of gas and charging of dust grains are dynamically evolving during the simulation, making the zone of high magnetic dissipation (’dead’ zone) variable. In our simulations, the jump in MRI-driven turbulent viscosity inside and outside of dead zone is insignificant. We find no hard edge, but rather a smooth transition between active and dead zone. Subsequently, there is no visible pressure bump at outer edge of the dead zone.

We investigate the age distributions of GC systems in 14 E/S0 galaxies by carrying out a differential comparison of the (g–z) vs. (g–K) two-colour diagrams for different GC systems. No significant distinction is detected in the mean ages of GCs among elliptical galaxies. S0 galaxies on the other hand, show evidence for younger GCs. Surprisingly, this appears to be driven by the more metal-poor clusters. This is suggestive of E type galaxies having assembled most of their GCs in a shorter and earlier period than lenticular galaxies. The latter galaxy type, seems to have a more extended period of GC formation/assembly.

Massive O- and B-type stars are “cosmic engines” in the Universe and can be the dominant source of luminosity in a galaxy. The class of Be stars are rapidly rotating B-type stars that lose mass in an equatorial, circumstellar disk (Porter & Rivinius 2003) and cause Balmer and other line emission. Currently, we are unsure as to why these stars rotate so quickly but three scenarios are possible: they may have been born as rapid rotators, spun up by binary mass transfer, or spun up during the main-sequence evolution of B stars. In order to investigate these scenarios for this population of massive stars, we have been spectroscopically observing a set of 115 field Be stars with the Kitt Peak Coudè Feed telescope in both the Hα and Hγ wavelength regimes since 2004. This time baseline allows for examination of variability properties of the circumstellar disks as well as determine candidates for closer examination for binarity. We find that 90% of the observed stars show some variability with 8% showing significant variability over the 5-year baseline. Such values may be compared with the significant variability seen in some clusters such as NGC 3766 (McSwain 2008). Also, while ~20% of the sample consists of known binaries, we find that another 15–30% of the sample shows indications of binarity.

EST European Solar Telescope is a pan-european project, presently in its Conceptual Design Study financed by the European Commission in the framework of FP7, involving 29 partners, from 14 different countries. The EST project is aimed at the realization of a 4-m class telescope, characterized by an optical design and a set of instruments optimized for extremely high resolution imaging and spectropolarimetric observations from near UV to NIR. EST will be four times larger than any existing high resolution solar telescope and it is designated with the highest priority among the ground-based, medium term (2016-2020) new projects in the ASTRONET Roadmap (Panel C). The EST instruments will measure fundamental astrophysical processes at their intrinsic scales in the Sun's atmosphere to establish the mechanism of magnetic field generation and removal, and of energy transfer from the surface to the upper solar atmosphere and eventually to the whole heliosphere. The conceptual Design Study started on February 2008 and will finish during 2011. EST will be operational at the same time as major ESA and NASA space missions aimed at studying solar activity.

Submillimeter observations are a key for answering many of the big questions in modern-day astrophysics, such as how stars and planets form, how galaxies evolve, and how material cycles through stars and the interstellar medium. With the upcoming large submillimeter facilities ALMA and Herschel a new window will open to study these questions. ARTIST is a project funded in context of the European ASTRONET program with the aim of developing a next generation model suite for comprehensive multi-dimensional radiative transfer calculations of the dust and line emission, as well as their polarization, to help interpret observations with these groundbreaking facilities.

Gyrosynchrotron (GS) emission of charged particles spiraling in magnetic fields plays an exceptionally important role in astrophysics. In particular, this mechanism makes a dominant contribution to the continuum solar and stellar radio emissions. However, the available exact equations describing the emission process are extremely slow computationally, thus limiting the diagnostic capabilities of radio observations. In this work, we present approximate GS codes capable of fast calculating the emission from anisotropic electron distributions. The computation time is reduced by several orders of magnitude compared with the exact formulae, while the computation error remains within a few percent. The codes are implemented as the executable modules callable from IDL; they are made available for users via web sites.

In this poster we present the results of our analyses of three early massive stars in IC 1613, whose spectra have been observed with VIMOS and analyzed with CMFGEN and FASTWIND. One of the targets resulted a possible LBV and the other two are Of stars with unexpectedly strong winds. The Of stars seem to be strongly contaminated by CNO products. Our preliminary results may represent a challenge for the theory of stellar atmospheres, but they still have to be confirmed by the analysis of more objects and a more complete coverage of the parameter space.

It is believed that CVs do not produce jets unlike other, more massive interactive binaries. Here we present spectrophotometric observations of the super-outburst of V455 And. We show here that a strong wind perpendicular the the accretion disc at the maximum of the super-otburst, i.e a jet, can probably explain the observed spectroscopic behavior of this system.

If it is commonly agreed that the presence of a (moderately) close stellar companion affects the formation and the dynamical evolution of giant planets, the frequency of giant planets residing in binary systems separated by less than 100 AU is unknown. To address this issue, we have conducted with VLT/NACO a systematic adaptive optics search for moderately close stellar companions to 130 nearby solar-type stars. According to the data from Doppler surveys, half of our targets host at least one planetary companion, while the other half show no evidence for short-period giant planets. We present here the final results of our survey, which include a new series of second-epoch measurements to test for common proper motion. The new observations confirm the physical association of two companion candidates and prove the unbound status of many others. These results strengthen our former conclusion that circumstellar giant planets are slightly less frequent in binaries with mean semimajor axes between 35 and 100 AU than in wider systems or around single stars.

The determination of prestellar core structure is often based on observations of (sub)millimeter dust continuum. However, recently the Spitzer Space Telescope provided us with IR images of many objects not only in emission but also in absorption. We developed a technique to reconstruct the density and temperature distributions of protostellar objects based on radiation transfer (RT) simulations both in mm and IR wavelengths. Best-fit model parameters are obtained with the genetic algorithm. We apply the method to two cores of Infrared Dark Clouds and show that their observations are better reproduced by a model with an embedded heating source despite the lack of 70 μm emission in one of these cores. Thus, the starless nature of massive cores can only be established with the careful case-by-case RT modeling.

Collision of the magnetic flux tubes in the Quiet Sun was proposed as one of the possible sources for the heating of the solar atmosphere (Furusawa and Sakai, 2000). The solar photosphere was observed using the New Solar Telescope ad Big Bear Solar Observatory. In TiO spectral line at 705.68 nm we approached resolution of 0.1″. The horizontal plasma wave was observed spreading from the larger bright point. Shorty after this wave an increase in the oscillatory power appeared at the same location as the observed bright point. This behavior matches some of the results from the simulation of the collision of the two flux tubes with a weak current.

The Galactic neutron star X-ray binary Her X-1 shows a 35-day photometric modulation. Detected across a broad energy range, the modulation is prevalent in X-rays, cycling between low and high states. Since the discovery of the 35-day cycle of Her X-1, the X-ray source has entered and returned from an extended anomalous low state on at least seven occasions. Employing Rossi X-ray Timing Explorer All-Sky Monitor observations, prior predictions that Her X-1 would return from the 2003 - 2004 anomalous low state with a new precession period and accretion luminosity are verified. However, the precession has not been as coherent over recent years as predicted. Potentially there have been more minor anomalous low states between 2004 and the present day.

Instabilities of nonuniform flows is a fundamental problem in dynamics of fluids and plasmas. This presentation outlines atypical dynamics of instabilities for unmagnetized and magnetized astrophysical differentially rotating flows, including, our efforts in the development of general theory of magneto rotation instability (MRI) that takes into account plasma compressibility, pressure anisotropy, dissipative and kinetic effects. Presented analysis of instability (transient growth) processes in unmagnetized/hydrodynamic astrophysical disks is based on the breakthrough of the hydrodynamic community in the 1990s in the understanding of shear flow non-normality induced dynamics. This analysis strongly suggests that the so-called bypass concept of turbulence, which has been developed by the hydrodynamic community for spectrally stable shear flows, can also be applied to Keplerian disks. It is also concluded that the vertical stratification of the disks is an important ingredient of dynamical processes resulting onset of turbulence.

The primary task of the Debrecen Observatory is the most detailed, reliable and precise documentation of the solar photospheric activity. This long-term effort started with the continuation of the Greenwich photoheliograph program, this is the Debrecen Photoheliographic Data (DPD) sunspot catalogue based on ground-based observations. The profile of the work has later been extended to space-borne observations (SOHO/MDI and SDO), to magnetic fields and faculae as well as to higher temporal resolution (one hour) and nearly real-time data supply. The database also includes historical observations. The web-presentation developed for the material is easy to search and browse. We describe the main characteristics of these catalogs, and their advantages. We summarize the recent advances in the procedure of their compilation, and the available sets of the data and images.

Mennickent et al. (2002) presented a catalogue of 1056 Be star candidates in the Small Magellanic cloud (SMC) by studying light curve variation using OGLE II data base. They classified these Be star candidates of the SMC in four categories: Type 1 stars showing outbursts (139 stars); Type 2 stars showing sudden luminosity jumps (154 stars); Type 3 stars showing periodic or near periodic variations (78 stars); Type 4 stars showing light curves similar to Galactic Be stars (658 stars). They suggested that Type 4 could be Be stars. On the other hand, they suggested that Type-3 stars may not be linked to the Be star phenomenon at all.

Cool core clusters of galaxies require strong feedback from their central AGN to offset cooling. We present a study of strong cool core, highly-luminous (most with Lx ≥ 1045 erg s−1), clusters of galaxies in which the mean central AGN jet power must be very high yet no central point X-ray source is detected. Using the unique spatial resolution of Chandra, a sample of 13 clusters is analysed, including A1835, A2204, and one of the most massive cool core clusters, RXCJ1504.1-0248. All of the central galaxies host a radio source, indicating an active nucleus, and no obvious X-ray point source. For all clusters in the sample, the nucleus has an X-ray bolometric luminosity below 2 per cent of that of the entire cluster. We investigate how these clusters can have such strong X-ray luminosities, short radiative cooling-times of the inner intracluster gas requiring strong energy feedback to counterbalance that cooling, and yet have such radiatively-inefficient cores with, on average, Lkin/Lnuc exceeding 200. Explanations of this puzzle carry significant implications for the origin and operation of jets, as well as on establishing the importance of kinetic feedback for the evolution of galaxies and their surrounding medium.

We present a model for high-energy flares in accreting black holes based on the injection in a magnetized corona of a non-thermal population of relativistic particles. Coupled transport equations are solved for all species of particles and the electromagnetic and neutrino output is predicted for the case of Galactic black holes.

I review the progress of SPH calculations for modelling galaxies, and resolving gas dynamics on GMC scales. SPH calculations first investigated the response of isothermal gas to a spiral potential, in the absence of self gravity and magnetic fields. Surprisingly though, even these simple calculations displayed substructure along the spiral arms. Numerical tests indicate that this substructure is still present at high resolution (100 million particles, ~10 pc), and is independent of the initial particle distribution. One interpretation of the formation of substructure is that smaller clouds can agglomerate into more massive GMCs via dissipative collisions. More recent calculations have investigated how other processes, such as the thermodynamics of the ISM, and self gravity affect this simple picture. Further research has focused on developing models with a more realistic spiral structure, either by including stars, or incorporating a tidal interaction.

Discoveries of extrasolar planets in tight binaries are of great scientific value since these systems can be used to gain new insights in planetary development processes. Gamma Cephei, one of the most thoroughly investigated double star systems is hosting a Jovian planet at a distance of about 2 AU from its primary, a 1.4 solar-mass K1 III-IV star (Neuhäuser et al. 2007; Torres 2007). We comprise aspects of dynamical stability, disc heating processes and different giant planet (GP) formation scenarios in order to gain a better understanding of the open questions that remain in explaining the formation of gamma Cephei b.