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Andreas Burkert (MPE/LMU)18/03/2013, 09:00
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Prof. Reinhard Genzel (MPE)18/03/2013, 09:15Review
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Dr Stefan Gillessen (MPE)18/03/2013, 10:00ReviewMeasurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a black hole four million times the mass of the Sun. With the exception of modest X-ray and infrared flares Sgr A* is surprisingly faint, suggesting that the accretion rate currently is very low. In 2011 we discovered a dense gas cloud approximately three times the...Go to contribution page
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Leo Meyer (University of California, Los Angeles)18/03/2013, 11:15HighlightWe present new observations and analysis of G2 – the intriguing red emission-line Galactic-center object that is fast approaching the central black hole on what appears to be a very eccentric orbit. The observations were obtained with the laser guide star Adaptive Optics systems on the W. M. Keck I and II telescopes and include spectroscopy (R ∼ 3600) centered on the Br-γ line and K’ (2.2 μm)...Go to contribution page
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Ruth Murray-Clay (Harvard University)18/03/2013, 11:45Highlight
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Nick Scoville (Caltech)18/03/2013, 14:00HighlightWe explore the possibility that the G2 gas cloud falling in towards Sgr A* is the mass loss envelope of a young TTauri star. As the star plunges to smaller radius at 1000 to 6000 km/s, a strong bow shock forms where the stellar wind is impacted by the hot X-ray emitting gas in the vicinity of Sgr A*. For a stellar mass loss rate of 4e-8 solar masses per yr and wind velocity 100 km/s, the bow...Go to contribution page
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Alessandro Ballone (MPE / LMU)18/03/2013, 14:30Some authors have suggested and studied the possibility of the gas and dust cloud G2 observed in the Galactic Center (Gillessen et al., 2012; 2013) being the outflow from a low luminosity star embedded in it (Gillessen et al., 2012; Burkert et al., 2012; Murray-Clay \& Loeb, 2012; Miralda-Escud\'e, 2012; Meyer \& Meyer-Hofmeister, 2012, Scoville, 2013). With the help of 2D hydrodynamical...Go to contribution page
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Jorge Cuadra (Universidad Católica de Chile)18/03/2013, 14:55The infalling cloud G2 is in a Keplerian orbit with apocentre in a region populated by Wolf-Rayet stars. As such, its origin is likely associated with the mass lost by these stars. We present numerical simulations of the gas dynamics in the inner parsec of the Galaxy, including the stars that produce copious amounts of stellar winds, and the gravitational potential of SgrA*. As expected,...Go to contribution page
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Mark Morris (University of California, Los Angeles)18/03/2013, 15:50Highlight
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Sergei Nayakshin (University of Leicester)18/03/2013, 16:20The centre of the Milky Way presents a unique environment in which to study AGN activity and its effects on the host galaxy. As is well known, the central parsec of the Galaxy hosted a significant episode of star formation some 5 million years ago. It has thus been suggested that a massive gas cloud (or two) fell into the centre of the Galaxy, got bound to Sgr A*, formed a disc and collapsed...Go to contribution page
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Diederik Kruijssen (MPA Garching)18/03/2013, 17:05It was recently found that the SFR in the Central Molecular Zone (CMZ, i.e. the central 500 pc) of the Milky Way is lower by a factor of 10-100 than expected for the substantial amount of dense gas it contains, which challenges existing star formation (SF) theories. I show that in terms of properties unrelated to SF activity, the CMZ follows several of the scaling relations that hold for...Go to contribution page
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Jens Thomas (Max-Planck-Institut für extraterrestrische Physik)18/03/2013, 17:30Based on new SINFONI observations, ten black hole masses occupying the high-mass regime of the M-sigma relation are presented, which are more massive than predicted by recent M-sigma and M-Lum relations. The effect of dark matter inclusion on the black hole masses is explored. In seven of the ten galaxies and in about 15 other galaxies we identified shallow central cores and the properties of...Go to contribution page
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Tobias Fritz (MPE)19/03/2013, 09:00I will present recent results for the nuclear cluster of Milky Way. Thereby, I concentrate on the old stars which dominate the mass budget. Firstly, I show a star density map of the cluster and use it to give a new estimate for its size. Secondly, I present an estimate for its mass from Jeans modeling using 23000 velocities. Finally, I relate these two properties with each other and with...Go to contribution page
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Oliver Pfuhl (MPE)19/03/2013, 09:25I will present the star formation history of the Milky Way's nuclear star cluster. We used spectroscopically derived temperatures of 450 cool giant stars within 1 pc from Sgr A* to construct a Hertzsprung–Russell diagram of the Galactic Center stellar population. By fitting the observed diagram with model populations we were able to derive the star formation history of the nuclear...Go to contribution page
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Eric Emsellem (ESO)19/03/2013, 09:50We have conducted a very high resolution simulation of a Milky-Way like galaxy including star formation, radiative feedback, etc. This AMR simulation follows all scales from the dark matter halo down to 0.05pc simultaneously (i.e., not a zoomed-in re-simulation). I will present results focused on the turbulence, central fueling, star-formation regimes, in the 200pc region around the...Go to contribution page
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Javiera Guedes (ETH Zurich)19/03/2013, 10:15In this work we use Eris, a high resolution cosmological simulation of the formation of a Milky Way-like late-type galaxy, to study the details of the formation and evolution of pseudobulges. We find that the pseudobulge forms early and its evolution is tightly interconnected with the evolution of the stellar bar, which is in turn affected by gas accretion and minor merger activity.Go to contribution page
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Moshe Elitzur (University of Kentucky)19/03/2013, 11:10Instead of a toroidal hydrostatic structure, disk outflow too can explain AGN obscuration. A central component of star formation, such outflows unify naturally many AGN observations, including broad line emission. Disk winds predict that both the torus and BLR disappear at low black-hole accretion rates, as observed. Recent observations reveal two stages in the broad line disappearance. In...Go to contribution page
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Konrad Tristram (MPIfR)19/03/2013, 11:55With interferometry in the infrared it is possible to directly resolve the thermal emission from the dusty torus in Active Galactic Nuclei. We can hence for the first time directly investigate the accreting material on parsec scales and test the unified scheme of AGN. The Circinus galaxy is ideal target for interferometric studies of its AGN-heated dust distribution, because it is the...Go to contribution page
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Leonard Burtscher (MPE)19/03/2013, 14:00Interferometric observations with MIDI/VLTI in the mid-infrared made studies of the central dusty tori of Active Galactic Nuclei (AGNs) possible and proved their existence in a few nearby galaxies. In an effort to enhance the existing sample to a number that would allow statistical questions to be asked, we have now completed a MIDI Large Programme comprising 16 nights of VLTI/UT time. The...Go to contribution page
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Almudena Prieto (IAC)19/03/2013, 14:25Low luminosity agns (LLAGNs) are posing a problem to the standard accretion AGN scenario because of their low radiation efficiency and the absence in their spectrum of the most significative feature of an accretion-disk: the blue bump. I will present results from high angular resolution observations in the IR of a set of prototype LLAGN which show that two other key features of AGN...Go to contribution page
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Ayse Ulubay-Siddiki (Istanbul University)19/03/2013, 14:50Warped megamaser discs in galactic nuclei provide a useful means of probing the close vicinity of the central black holes. The observations of some of the systems in nearby AGN, such as NGC1068 and Circinus, might be indicating the existence of a highly inclined, massive disc, prone to forming stars. We study for various surface density profiles, and disc radial extents, the long term...Go to contribution page
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Richard Davies (MPE)19/03/2013, 15:45There is increasing evidence that Seyfert nuclei in local galaxies do not co-exist with active phases of star formation in their local environment. However, the question of whether AGN are associated with post-starbursts is not settled. I will show the first results from a new project to tackle this issue by looking for direct evidence of AGB stars close around AGN. I will then discuss recent...Go to contribution page
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Sandra Raimundo (SISSA (International School for Advanced Studies))19/03/2013, 16:30In this work, we present the first results of integral-field spectroscopy observations with SINFONI, targeting the inner 400 pc of MCG--6-30-15. This Narrow-Line Seyfert 1 galaxy provides an important test case to probe AGN fuelling at higher X-ray luminosities. With the H-band data, we are able to model and remove the AGN contribution and hence probe the galaxy's stellar and gas...Go to contribution page
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Carole Mundell (Astrophysics Research Institute, Liverpool JM University)19/03/2013, 16:55The distribution of gas and stars in nearby galaxies traced by '3-D' studies of molecular, neutral and ionised gas provide a unique view of the role of the multi-phase medium in triggering and fuelling nuclear activity in galactic nuclei on size scales ever closer to the central black hole. I will highlight the importance of such 3D studies at optical, radio and mm wavelengths and, in...Go to contribution page
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Jeremiah P. Ostriker (Princeton University)19/03/2013, 17:20HighlightMassive elliptical galaxies universally host in their centers black holes with masses roughly proportional to the stellar masses of the hosts. Periodically, gas will accumulate at the centers of these systems due either (at early times) due to cosmological infall or (at later times) to secondary gas consequent to normal stellar evolution. This material will fuel central star-formation episodes...Go to contribution page
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Dr Thorsten Naab (MPA Garching)20/03/2013, 09:00
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Javier Rodriguez (Instituto de Astrofísica de Canarias (IAC))20/03/2013, 09:45We have carried out an optical spectroscopic study of a sample of nearby ULIRGs with Seyfert nuclei, with the aim of investigating the nature of the nuclear warm gas outflows. We will complement this study with HST ACS/WFC and STIS observations to make high resolution [OIII]5007 emission line imaging and long-slit spectroscopy observations of the circumnuclear outflows in a sample of ULIRGs...Go to contribution page
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Beatriz Villarroel (Dept. of Physics and Astronomy, Uppsala University)20/03/2013, 10:10We have used the Sloan Digital Sky Survey (DR7) and Galaxy Zoo data to examine close neighbours to low-redshift Type-1 and Type-2 AGN. Our results show a strong color-distance relation for Type-2 AGN neighbours (but none for Type-1 AGN). We also see a trend in the ratio #Type-1/#Type-2 AGN neighbours to Type-2 AGN as a function of projected distance. Further, while 22% of the Type-1 AGN...Go to contribution page
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Pedro R. Capelo (University of Michigan)20/03/2013, 11:05We present the latest results from a suite of high-resolution hydrodynamical simulations of mergers between two disk galaxies, in which we vary the mass ratio and the directions of the two galactic angular momentum vectors. We study both the evolution of the central black holes and the fate of the galaxies themselves. One newly found aspect of galactic interaction is the occurrence, in some...Go to contribution page
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Farhad Yusef-Zadeh (Northwestern University)20/03/2013, 11:30There are several sources of interest in the unique region of the Galaxy surrounding Sgr A*. I will focus on two topics related to Sgr A*. One discusses the flare activity which suggests the evidence for a relativistic outflow. We consider the possibility that G2 may encounter with this relativistic jet-driven outflow. I will present the light curves of Sgr A* at X-ray and radio wavelengths...Go to contribution page
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Martin Hardcastle (University of Hertfordshire)21/03/2013, 09:00ReviewI will discuss the relationship between radio-loud AGN activity and star formation, based on recent large-scale studies of star-formation activity in radio galaxy together with detailed studies of individual systems carried out over many years. It is clear that radio jets can have a dramatic impact on all phases of gas in the central regions of the host galaxy, but the detailed relationship...Go to contribution page
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Volker Gaibler (ITA, University of Heidelberg)21/03/2013, 09:45TalkIt is well known that the interstellar medium of galaxies has a highly complex structure. Yet, hydrodynamical simulations of active galactic nuclei have only recently started to actually take into account the strongly inhomogeneous nature of the ISM that they are interacting with. I will present recent simulation results on how nuclear black hole activity can enhance or trigger...Go to contribution page
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Dr Martin Krause (TUM / MPE)21/03/2013, 10:10TalkAfter the detection of the 10 kpc diameter high-energy lobes above and below the Milky Way, the Milky Way's jets have recently been directly seen in Gamma rays, X-rays and in the radio band. I will report our recent simulations on the interactions of jets with the hot gas, which leads to collimation and determines the kpc-scale morphology, and also with molecular clouds close to the Galactic...Go to contribution page
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Julia Scharwaechter (Observatoire de Paris, LERMA)21/03/2013, 11:05TalkA detailed knowledge of the properties of the multi-phase ISM is crucial for constraining models of AGN accretion and feedback. Both accretion and jet feedback are possible energy sources for driving shocks and turbulence in the molecular gas component. Our recent study of the near-infrared molecular hydrogen (H_2) emission in the central ~300 pc of NGC 1275 (Perseus A) suggests a scenario...Go to contribution page
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Mohammad Zamaninasab (Max-Plack-Institut fuer Radioastronomie)21/03/2013, 11:30TalkMost current theoretical models relate launching of relativistic jets from active galac- tic nuclei to the presence of twisted magnetic fields close to the supermassive black hole. While these models predict a large-scale, ordered, helical magnetic field near the central engine, it is not clear if, and to what extent, this order is preserved further downstream in the jet. Here we present the...Go to contribution page
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Dr Andrea Merloni (MPE)21/03/2013, 14:00ReviewHow did supermassive black holes form and grow in the nuclei of galaxies? Why are their physical properties today so tightly linked to those of their hosts? What was the impact on the surrounding structures of the copious energy release, either in radiative or mechanical form, associated to the growth of such black holes in active galactic nuclei (AGN)? I will show how constraints available...Go to contribution page
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Dr Michaela Hirschmann (Osservatorio Astronomico di Trieste INAF)21/03/2013, 14:45HighlightObservational studies have revealed a “downsizing” trend in black hole (BH) growth: the number densities of luminous AGN peak at higher redshifts than those of faint AGN. This would seem to imply that massive black holes formed before low mass black holes, in apparent contradiction to hierarchical clustering scenarios. We investigate whether this observed “downsizing” in BH growth is...Go to contribution page
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Bhaskar Agarwal (MPE)21/03/2013, 15:45I will speak about an unconventional way of forming massive seed black holes (BHs) where pristine gas in the early universe is able to withstand fragmentation into stars, owing to a high level of extragalactic Lyman-Werner radiation, and directly collapses into a BH with mass 1.e4-1.e5 Msol. If these BHs can form and exist at z>6, there would be some interesting implications on the...Go to contribution page
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Muhammad Latif (Institute for Astrophysics, Göttingen)21/03/2013, 16:10The existence of supermassive black holes is confirmed at z 6. We explore their formation in the early universe performing high resolution cosmological simulations. We employ the highest resolution per Jeans length to date, allowing us to model turbulence on resolved scales, and in addition employ a subgrid scale model for turbulence on unresolved scales. Our findings show that fragmentation...Go to contribution page
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Monika Moscibrodzka (Department of Astrophysics, Radboud University Nijmegen)21/03/2013, 16:35I will present highlights of numerical simulations of gas falling onto a black hole in the center of the Milky Way. Our models predicts dynamical and radiative properties of a hot accretion flows around a Kerr black hole. I will show how the Sgr A* observational data put constraints on the model parameters such as viewing angle, spin of the black hole or mass accretion rate. Since there is a...Go to contribution page
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Paramita Barai (INAF - Osservatorio Astronomico di Trieste)21/03/2013, 17:05I will report our investigation of gas accretion and radiative feedback in the SMBH of active galaxies (Barai, Proga & Nagamine 2011, 2012). We perform simulations using the 3D SPH code Gadget-3, without and with radiative heating by the central X-ray source and cooling. We find that the accretion mode depends on the X-ray luminosity (L_X). At low-L_X, gas accretes in a stable,...Go to contribution page
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Takamitsu Tanaka (MPA Garching)22/03/2013, 09:00Supermassive black hole binaries are inevitable byproducts of hierarchical structure formation. I will discuss several variable electromagnetic emission signatures predicted for such binaries when they accrete as luminous active galactic nuclei, including a class of transients that may masquerade as tidal disruption events. The predicted variable signatures should be observed by forthcoming...Go to contribution page
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Heino Falcke (Radboud University Nijmegen & ASTRON)22/03/2013, 09:25Black holes are supposed to power the nuclei of galaxies. The best place to test this paradigm is the Galactic center. Here a compact radio source, Sgr A*, with a mass of 4 Million solar masses marks the very center of our Galaxy. Numerical magnetohydrodynamic simulations and semi-analytic models seem to converge towards a combined jet-disk model producing radiation from radio to X-rays to...Go to contribution page
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Frank Eisenhauer (MPE)22/03/2013, 10:40GRAVITY is a new instrument to combine the four 8m ESO Very Large Telescopes in Chile. Providing precision astrometry of order 10 microarcseconds and infrared imaging with 4-milliarcsecond resolution, GRAVITY will address a number of fundamental open questions on the Galactic Center black hole and its surrounding: What is the nature of its flares? What is the spin of the black hole? How can we...Go to contribution page
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Thomas Boller (MPE)22/03/2013, 11:25Gravitation is very well des- cribed by Einstein's General Relativity. However, several theoretical predictions like the existence of curvature singularities and event horizons are under debate. We contrast predictions made by General Relativity with the pseudo–complex field theory proposed recently. Among them we study the gravitational redshift effect, perihelion shift, orbital motion,...Go to contribution page
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Jeremiah P. Ostriker (Princeton University)22/03/2013, 11:50
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Hitoshi Hanami (Iwate University)TalkWe have been studying the star-Formation and AGN activities in galaxies up to z~2, which were detected with the AKARI in some Subaru survey fields. As recently reported in Hanami et al. (2012; PASJ, 64, 70), the AKARI/IRC Mid-InfraRed (MIR) multiband photometry is effective not only to distinguish between the star-forming and AGN activities, but also estimate their dust-obscured SFRs and...Go to contribution page
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Ralf Bender (USM/MPE)Review
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Dr Marc Schartmann (LMU / MPE)
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