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))
Norbert Schartel
(ESA)
15/12/2015, 14:00
Talk
With 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...
Immacolata Donnarumma
(National Institute for Astrophysics - INAF)
15/12/2015, 14:21
Talk
We 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...
Krzysztof Hryniewicz
(Nicolaus Copernicus Astronomical Centre)
15/12/2015, 14:42
Talk
Thanks 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...
Dr
Melania Del Santo
(National Institute for Astrophysics - INAF)
15/12/2015, 15:02
Talk
In 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...
Wenfei Yu
(Shanghai Astronomical Observatory)
15/12/2015, 15:22
Talk
When 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...
Xavier Barcons
(Instituto de Fรญsica de Cantabria (CSIC-UC))
15/12/2015, 16:15
Talk
ESAโs *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...
Dr
Wako Ishibashi
(ETH Zurich)
15/12/2015, 16:40
Talk
Black 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...
Prof.
Lucio Mayer
(University of Zurich)
15/12/2015, 17:00
Talk
We 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...
Prof.
andres escala
(Universidad de chile)
15/12/2015, 17:20
Talk
By 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 ...
Dr
Sergey Sazonov
(Space Research Institute, Moscow, Russia)
15/12/2015, 17:40
Talk
We 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...
Ingyin Zaw
(NYU Abu Dhabi)
15/12/2015, 18:20
Poster
NGC 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...
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, 18:23
Poster
A 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...
Dr
Adam Ingram
(University of Amsterdam)
16/12/2015, 14:00
Talk
Accreting 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...
Eugenio Bottacini
(Stanford University)
16/12/2015, 14:25
Talk
Most 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...
Lorenzo Natalucci
(Istituto di Astrofisica e Planetologia Spaziali, INAF)
16/12/2015, 14:47
Talk
The 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...
Dr
George Chartas
(College of Charleston)
16/12/2015, 15:12
Talk
We 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...
Masaaki Takahashi
(AIchi University of Education)
16/12/2015, 15:33
Poster
The 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...
Ms
Paola Rioseco
(IFM-UMICH)
16/12/2015, 15:36
Poster
We 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...
Ms
Dolunay Kocak
(University of Ege),
Kadri Yakut
(University of EGE)
16/12/2015, 15:39
Poster
In 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.
Mr
Varadarajan Parthasarathy
(N. Copernicus Astronomical Center)
16/12/2015, 15:42
Poster
Our 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...
Vittorio De Falco
(University of Basel)
16/12/2015, 16:35
Talk
In 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...
Prof.
Isao Okamoto
(National Astronomical Observatory of Japan)
16/12/2015, 16:55
Talk
Making 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...
Ksenia Ptitsyna
(INR Moscow, MSU Moscow, ISDC Geneve)
16/12/2015, 17:15
Poster
We 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...
Prof.
Benjamin Koch
(Pontifica Universidad Catolica de Chile)
16/12/2015, 17:18
Poster
It 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.
Kadri Yakut
(University of EGE),
ismail รถzbakฤฑr
16/12/2015, 17:21
Poster
In 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.
Dragan Hajdukovic
(Institute of Physics, Astrophysics and Cosmology (ME))
16/12/2015, 17:24
Poster
While 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...
