Conveners
16 - Black holes
- Didier Barret (IRAP (UPS/CNRS))
16 - Black holes
- Didier Barret (IRAP (UPS/CNRS))
16 - Black holes
- Didier Barret (IRAP (UPS/CNRS))
16 - Black holes
- Didier Barret (IRAP (UPS/CNRS))
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Norbert Schartel (ESA)15/12/2015, 14:00TalkWith about 300 refereed papers published each year, XMM-Newton is one of the most successful scientific missions of ESA ever. Observations of Galactic as well as supermassive black holes, where relativistic effects have to be accounted for, play a major role in XMM-Newton's observing program. The main focus of the talk will be the discussion of scientific highlight results based on XMM-Newton...Go to contribution page
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Immacolata Donnarumma (National Institute for Astrophysics - INAF)15/12/2015, 14:21TalkWe will report on the discovery potential of relativistic tidal disruption events with current and future instruments and its impact on the SuperMassive black hole mass function and the theory of jet formation. Relativistic TDEs (or jetted TDEs) are a new class of sources, recently discovered by Swift/BAT, showing a significant radio counterpart of a common tidal disruption event. Observing...Go to contribution page
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Krzysztof Hryniewicz (Nicolaus Copernicus Astronomical Centre)15/12/2015, 14:42TalkThanks to their thermal emission, Tidal Disruption Events (TDEs) were detected regularly in the soft X-rays and sometimes in the optical. Only few of them have been detected at hard X-rays: two are high redshift beamed events, one occurred at the core of a nearby galaxy and the last one is of a different nature, involving a compact object in the Milky Way. The aims of presented work are to...Go to contribution page
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Dr Melania Del Santo (National Institute for Astrophysics - INAF)15/12/2015, 15:02TalkIn 2011 a new hard X-ray source, IGR J17361-4441, was discovered by INTEGRAL close the centre of the globular cluster NGC 6388. Based on its peak luminosity, it was classified as very faint X-ray transient. A Swift/XRT monitoring campaign showed an evident t^(-5/3) trend in the light curve, and a thermal emission of ยยยย~0.08 keV that did not evolve significantly with time. We...Go to contribution page
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Wenfei Yu (Shanghai Astronomical Observatory)15/12/2015, 15:22TalkWhen normal stars run close enough to the previously dormant supermassive black holes (SMBHs) at the centres of normal galaxies, they would be entirely or partly disrupted due to the tidal force, leading to the so-called tidal disruption events (TDEs). Part of the debris material will be accreted by the SMBHs later on. The accretion of the debris material would generate X-ray flares, which...Go to contribution page
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Naoki Seto15/12/2015, 15:42PosterWe geometrically analyze the evolution of the Kozai-Lidov mechanism induced by an infalling tertiary. This approach enables us to clearly understand how the inner orbits are deformed, in response to the time variation of the related phase-space structure. We predict that, in a stellar cluster associated with massive black hole binaries, a constituent star could abruptly become highly...Go to contribution page
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Xavier Barcons (Instituto de Fรญsica de Cantabria (CSIC-UC))15/12/2015, 16:15TalkESAโs *Athena* (Advanced Telescope for High-Energy Astrophysics) X-ray observatory mission, to be launched in 2028, will revolutionise our knowledge of the hot and energetic Universe. The X-IFU (X-ray Integral Field Unit) is one of the two instruments on the focal plane of its large X-ray telescope, providing sensitive spatially resolved high-resolution spectroscopy. *Athena*/X-IFU will...Go to contribution page
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Dr Wako Ishibashi (ETH Zurich)15/12/2015, 16:40TalkBlack holes in active galactic nuclei (AGN) respond to the accretion process by feeding back energy and momentum into the surroundings. Such AGN feedback is generally invoked to quench star formation in host galaxies, either by heating or removing the ambient gas. However, feedback from the accreting black hole may also play other roles in galaxy evolution.We consider the role of radiation...Go to contribution page
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Prof. Lucio Mayer (University of Zurich)15/12/2015, 17:00TalkWe present the latest developments of the merger-driven scenario for supermassive black hole formation originally developed in Mayer et al. (2010, Nature, 466. 1082). We show how including realistic radiation physics in mergers of protogalaxies driven from cosmological initial conditions strengthens the proposal that supermassive nuclear clouds may form in only a few 10^8 yr in the nucleus of...Go to contribution page
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Prof. andres escala (Universidad de chile)15/12/2015, 17:20TalkBy using AMR cosmological hydrodynamic N-body zoom-in simulations, with the RAMSES code, we studied the mass transport processes onto galactic nuclei from high redshift up to z~6. Due to the large dynamical range of the simulations we were able to study the mass accretion process on scales from ~50 kpc to ~pc. The SMBHs are modelled as a sink particles at the center of our galaxies, which ...Go to contribution page
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Dr Sergey Sazonov (Space Research Institute, Moscow, Russia)15/12/2015, 17:40TalkWe have utilized a local AGN sample from the INTEGRAL all-sky hard X-ray survey to investigate if the well-known declining trend of the fraction of obscured AGN with increasing luminosity is mostly an intrinsic or selection effect. We show that in addition to negative bias, due to absorption in the torus, in finding obscured AGN, there is positive bias in finding unobscured AGN, due to Compton...Go to contribution page
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Valentino Esposito15/12/2015, 18:00TalkThe diffuse cosmic X-ray background1 (CXB)ย is the sum of the emission of discrete sources, mostly massive black-holes accreting matter in active galactic nuclei (AGN)2. The CXB spectrum differs from the integration of the spectra of individual sources, calling for a large population, undetected so far, of strongly obscured Compton thick AGN3. Such objects are predicted by unified models4,...Go to contribution page
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Ingyin Zaw (NYU Abu Dhabi)15/12/2015, 18:20PosterNGC 4945, one of the closest starburst-AGN presents a unique laboratory for testing the interplay between AGN accretion and star formation. It is the brightest extragalactic source of hard X-rays but is highly obscured below 10 keV. Its proximity allows for mapping the inner-most parsec of the galactic nucleus using very long baseline interferometry of the unobscured 22 GHz water maser...Go to contribution page
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Dr Erika Benitez (Instituto de Astronomia, Universidad Nacional Autonoma de Mexico (UNAM)), Dr Sergio Mendoza (Instituto de Astronomia, Universidad Nacional Autonoma de Mexico)15/12/2015, 18:23PosterA model independent power spectrum light curve analysis in the optical, hard X-ray and gamma-rays of the blazar MRK 421 shows clear evidence for a periodicity of approximately 400 days. A subsequent full maximum likelihood analysis fitting an eclipse model confirms this periodicity with a consistent phase for the bands analysed. The most parsimonious physical mechanism to which this...Go to contribution page
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Valentino Esposito15/12/2015, 18:26PosterThe high energy spectrum of 3C 273 is usually understood in terms of inverse-Compton emission in a relativistic leptonic jet. This model predicts variability patterns and delays that could be tested with simultaneous observations from the radio to the GeV range. The instruments IBIS, SPI, JEM-X on board INTEGRAL, PCA on board RXTE, and LAT on board Fermi have enough sensitivity to follow the...Go to contribution page
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Dr Adam Ingram (University of Amsterdam)16/12/2015, 14:00TalkAccreting stellar mass black holes often show a quasi-periodic oscillation (QPO) in their X-ray flux with a period that slowly drifts from ~10s to ~0.05s and an iron emission line in their X-ray spectrum. The iron line is generated by fluorescent re-emission, by the accretion disk, of X-ray photons originating in the innermost hot flow. The line shape is distorted by relativistic motion of the...Go to contribution page
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Eugenio Bottacini (Stanford University)16/12/2015, 14:25TalkMost galaxies undergo one or more eras of Active Galactic Nucleus (AGN) activity throughout their existence. During this era their environment around the central super-massive black hole emits from X-ray to soft gamma-ray energies. Therefore these spectra and their features carry the information of the extreme gravitational conditions. However these spectral features can be transient and...Go to contribution page
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Lorenzo Natalucci (Istituto di Astrofisica e Planetologia Spaziali, INAF)16/12/2015, 14:47TalkThe black hole binary V404 Cygni exhibited an unprecedently bright outburst on 2015, June 15. Since then, many space and ground observing facilities monitored the flux from the source during several weeks, until its decline to a near-quiescent state in late July-August. The source was extremely variable at all wavelenghts. The radio versus X-ray flux variations are reminiscent of the already...Go to contribution page
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Dr George Chartas (College of Charleston)16/12/2015, 15:12TalkWe present a promising new technique (g-distribution method) for measuring the innermost stable circular orbit (ISCO), the inclination angle (i), and the spin of a supermassive black hole. The g-distribution method involves measurements of the distribution of the energy shifts of the relativistic iron line emitted from the accretion disk of a supermassive black hole that is microlensed by...Go to contribution page
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Masaaki Takahashi (AIchi University of Education)16/12/2015, 15:33PosterThe formation of standing magnetohydrodynamical (MHD) shocks by accreting plasma in a black hole magnetosphere is studied. The black hole magnetosphere would be formed around a black hole with an accretion disk. The global magnetic field lines would be originated by currents in the accretion disk and its corona, and then some part of magnetic field lines would lead to the event horizon. Along...Go to contribution page
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Ms Paola Rioseco (IFM-UMICH)16/12/2015, 15:36PosterWe analyze the accretion of gas into a black hole background space-time in the context of relativistic kinetic theory. The state of the gas is described by a distribution function which has to satisfy the general relativistic Boltzmann equation. In the first part of this work, we describe a method to find the most general solution of this equation in the collisionless case. In the second...Go to contribution page
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Ms Dolunay Kocak (University of Ege), Kadri Yakut (University of EGE)16/12/2015, 15:39PosterIn this study, we present angular momentum loss mechanism through gravitational radiation for the selected X-ray binary systems. Gravitational radiation time-scale is estimated for each selected system. In addition, their gravitational wave amplitudes are also estimated and their detectability with gravitational wave detectors has been discussed.Go to contribution page
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Mr Varadarajan Parthasarathy (N. Copernicus Astronomical Center)16/12/2015, 15:42PosterOur research focuses on axisymmetric hydrodynamical simulations. The models implemented are *thinner* tori and *thicker* torus in equilibrium around a non-rotating black hole. The tori were constructed with a constant distribution of angular momentum obtained from Kluzniak-Lee (a pseudo-Newtonian) potential. Epicyclic motion were triggered by adding sub-sonic velocity fields; radial, vertical...Go to contribution page
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Magnus Axelsson16/12/2015, 16:15TalkThe geometry of the inner accretion flow of X-ray binaries is complex, with multiple regions contributing to the observed emission. Frequency-resolved spectroscopy is a powerful tool in breaking this spectral degeneracy. We have extracted the spectra of the strong low-frequency quasi-periodic oscillation (QPO) and its harmonic in GX339-4 and XTE J1550-564, and compare these to the...Go to contribution page
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Vittorio De Falco (University of Basel)16/12/2015, 16:35TalkIn this talk I consider the light path of observed photons emitted by matter in a *Schwarzschild gravitational field*. *Ray-tracing methods* are employed to tackle this problem and the used main equations are: **light bending**, **time delay** and **solid angle**. They are expressed through *elliptic integrals* that can be resolved numerically through generally complex routines. To run faster...Go to contribution page
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Prof. Isao Okamoto (National Astronomical Observatory of Japan)16/12/2015, 16:55TalkMaking use of $3+1$ formulation of black hole electrodynamics, it is argued that the frame-dragging effect combines with unipolar induction, to sustain the double-structured magnetosphere consisting of the outer and inner domains, and high-energy activities therein. The emf's, $\cal{E}_{\rm out}$ and $\cal{E}_{\rm in}$, of a pair of unipolar induction batteries driving electric currents in the...Go to contribution page
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Ksenia Ptitsyna (INR Moscow, MSU Moscow, ISDC Geneve)16/12/2015, 17:15PosterWe consider the possible existence and observational consequences of the so-called vacuum "gaps" in the SMBH force-free magnetospheres in RIAF type sources. The gaps are the sites with a lack of the volume charge density in comparison to the plasma-filled force-free regions of the magnetosphere. They are analogous to the gaps in the pulsars magnetospheres. In such gaps direct acceleration of...Go to contribution page
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Prof. Benjamin Koch (Pontifica Universidad Catolica de Chile)16/12/2015, 17:18PosterIt is a well known effect that a rotating black hole can accelerate spinless particles to in principle arbitrary energies. Within the formalism of the Spinning Top it is investigated to which extend the "corresponding" process is also possible: *"Can spinning tops be accelerated by a non-rotating black hole?"* It is found that this is indeed the case.Go to contribution page
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Kadri Yakut (University of EGE), ismail รถzbakฤฑr16/12/2015, 17:21PosterIn this study, accurate and detailed solution of the frame-dragging process has been presented with a newly deduced equation of motion. Numerical solutions show that the results obtained in this study are somewhat different than those results presented in Thirring (1918). Obtained results have been applied to various astrophysical mediums as case studies.Go to contribution page
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Dragan Hajdukovic (Institute of Physics, Astrophysics and Cosmology (ME))16/12/2015, 17:24PosterWhile it is neglected, Hawking radiation is model-dependent; it depends on our model of the quantum vacuum. It was recently suggested that what we call dark matter and dark energy can be explained as the local and global effects of the gravitational polarization of the quantum vacuum by the immersed Standard Model matter. This result appears as the consequence of the working hypothesis that...Go to contribution page