A5069499982- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Mechanics and Biomechanics Studies
- Astronomical Observations and Instrumentation
- Heat Transfer Mechanisms
- Spectroscopy and Laser Applications
- History and Developments in Astronomy
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Experimental and Theoretical Physics Studies
- Gas Dynamics and Kinetic Theory
- Historical Astronomy and Related Studies
- Superconductivity in MgB2 and Alloys
- Sports Dynamics and Biomechanics
- Fluid Dynamics Simulations and Interactions
- Meteorological Phenomena and Simulations
- Plasma and Flow Control in Aerodynamics
Max Planck Institute for Extraterrestrial Physics
2012-2021
Ludwig-Maximilians-Universität München
2009-2020
Excellence Cluster Origins
2019-2020
Stuttgart Observatory
2009-2020
Swinburne University of Technology
2015-2018
Optica
2008-2015
Max Planck Society
2008-2015
Bayerische Staatssammlung für Paläontologie und Geologie
2010-2015
Federal Foreign Office
2009-2013
Max Planck Institute for Astronomy
2005-2010
The AGN-heated dust distribution (the "torus") is increasingly recognized not only as the absorber required in unifying models, but a tracer for reservoir that feeds nuclear Super-Massive Black Hole. Yet, even its most basic structural properties (such extent, geometry and elongation) are unknown all few archetypal objects. Since AGNs unresolved mid-infrared, we utilize MID-infrared interferometric Instrument (MIDI) at Very Large Telescope Interferometer (VLTI) sensitive to structures small...
Aims.To test the dust torus model for active galactic nuclei directly, we study extent and morphology of nuclear distribution in Circinus galaxy using high resolution interferometric observations mid-infrared.
Tori of Active Galactic Nuclei are made up a mixture hot and cold gas, as well dust. In order to protect the dust grains from destruction by gas energetic radiation accretion disk, is often assumed be distributed in clouds. our new 3D model AGN tori, torus modelled wedge-shaped disk which dusty clouds randomly distributed, taking density distribution corresponding continuous into account. We especially concentrate on differences between clumpy models terms temperature distributions, surface...
Context. With infrared interferometry it is possible to resolve the nuclear dust distributions that are commonly associated with dusty torus in active galactic nuclei (AGN). The Circinus galaxy hosts closest Seyfert 2 nucleus and previous interferometric observations have shown its emission particularly well resolved.
Context. Detailed high resolution studies of AGN with mid-infrared (MIR) interferometry have revealed parsec-sized dust emission elongated in the polar direction four sources. Aims. Using a larger, coherently analyzed sample observed MIR interferometry, we aim to identify statistical More specifically wish determine if there is indeed preferred elongation and whether this consistent torus-like structure or emission. Methods. We investigate significance detection an shape by fitting Gaussian...
The origin, structure and evolution of the small gas cloud, G2, is investigated, that on an orbit almost straight into Galactic central supermassive black hole (SMBH). G2 a sensitive probe hot accretion zone Sgr A*, requiring temperatures densities agree well with models captured shock-heated stellar winds. Its mass equal to critical below which cold clumps would be destroyed quickly by evaporation. also constrained fact at apocenter its sound crossing timescale was orbital timescale. Our...
We report on the determination of electron densities, and their impact outflow masses rates, measured in central few hundred parsecs 11 local luminous active galaxies. show that peak integrated line emission AGN is significantly offset from systemic velocity as traced by stellar absorption features, indicating profiles are dominated outflow. In contrast, matched inactive galaxies characterised a weaker wing. present three independent estimates density these AGN, discussing merits different...
The structures and dynamics of molecular, atomic, ionized gases are studied around a low-luminosity active galactic nucleus (AGN) with small ($2\times 10^6 M_\odot$) black hole using 3D radiation hydrodynamic simulations. We studied, for the first time, non-equilibrium chemistry X-ray dominated region in "radiation-driven fountain" (Wada 2012) supernova feedback. A double hollow cone structure is naturally formed without postulating thick "torus" central source. occupied an inhomogeneous,...
We present near-infrared interferometric data on the Seyfert 2 galaxy NGC 1068, obtained with GRAVITY instrument European Southern Observatory Very Large Telescope Interferometer. The extensive baseline coverage from 5 to 60 M\lambda allowed us reconstruct a continuum image of nucleus an unrivaled 0.2 pc resolution in K-band. find thin ring-like structure emission radius r = 0.24+/-0.03 pc, inclination i 70+/-5 deg, position angle PA -50+/-4 and h/r < 0.14, which we associate dust...
Using VLTI/GRAVITY and SINFONI data, we investigate the subparsec gas dust structure around nearby type 1 active galactic nucleus (AGN) hosted by NGC 3783. The K -band coverage of GRAVITY uniquely allows simultaneous analysis size kinematics broad line region (BLR), near-infrared(near-IR)-continuum-emitting hot dust, coronal (CLR). We find BLR, probed through Br γ emission, to be well described a rotating, thick disc with radial distribution clouds peaking in inner region. In our BLR model,...
We explore physically self-consistent models of dusty molecular tori in Active Galactic Nuclei (AGN) with the goal interpreting VLTI observations and fitting high resolution mid-IR spectral energy distributions (SEDs). The input dust distribution is analytically calculated by assuming hydrostatic equilibrium between pressure forces - due to turbulent motion gas clouds gravitational centrifugal as a result contribution nuclear stellar central black hole. For fully three-dimensional treatment...
Narrow-Line Seyfert 1 (NLS1) galaxies show extreme properties with respect to the other galaxies. Indeed, they are thought be accreting at Eddington rates and possess low mass black holes. Therefore, may represent a key class of objects for understanding co-evolution holes their host We propose that NLS1s AGN in which hole growth is, has always been, dominated by secular evolution. Firstly, looking NLS1 galaxy literature, we evolution is presently driven processes, much more so than...
We present new observations of the recently discovered gas cloud G2 currently falling towards massive black hole in Galactic Center. The data confirm that is on a highly elliptical orbit with predicted pericenter passage mid 2013. updated has an even larger eccentricity 0.966, epoch two months later than estimated before, and nominal minimum distance 2200 Schwarzschild radii only. velocity gradient developed further to 600 km/s FWHM summer 2012. also detect tail similar total flux same as...
We present new, deep near-infrared SINFONI @ VLT integral field spectroscopy of the gas cloud G2 in Galactic Center, from late summer 2013 and spring 2014. is visible recombination line emission. The spatially resolved kinematic data track ongoing tidal disruption. As expected for an observation near pericenter passage, roughly half 2014 found at redshifted, pre-pericenter side orbit, while other post-pericenter, blueshifted side. also orbital solution G1, which was discovered a decade ago...
We investigate the origin and fate of recently discovered gas cloud G2 close to Galactic center. Our hydrodynamical simulations focusing on dynamical evolution in combination with currently available observations favor two scenarios: a Compact Cloud which started around year 1995 Spherical Shell gas, an apocenter distance within disk(s) young stars radius few times size Cloud. The former is able explain detected signal position–velocity (PV) diagram Brγ emission 2008.5 2011.5 data. latter...
Stellar winds and supernova (SN) explosions of massive stars (‘stellar feedback’) create bubbles in the interstellar medium (ISM) insert newly produced heavy elements kinetic energy into their surroundings, possibly driving turbulence. Most this is thermalized immediately removed from ISM by radiative cooling. The rest available for dynamics. In work we estimate amount feedback retained as when bubble walls have decelerated to sound speed ambient medium. We show that most star outweighs less...
We have further followed the evolution of orbital and physical properties G2, object currently falling toward massive black hole in Galactic Center on a near-radial orbit. New, very sensitive data were taken 2013 April with NACO SINFONI at ESO VLT. The "head" G2 continues to be stretched ever along orbit position–velocity space. A fraction its emission appears already emerging blueshifted side orbit, past pericenter approach. Ionized gas head is now over more than 15,000 Schwarzschild radii...
We describe a complete volume limited sample of nearby active galaxies selected by their 14–195 keV luminosity, and outline its rationale for studying the mechanisms regulating gas inflow outflow. also complementary inactive galaxies, to match host galaxy properties. The appears have no bias in terms galactic nucleus (AGN) type, only difference being neutral absorbing column, which is two orders magnitude greater Seyfert 2s. In luminosity range spanned sample, –43.7, optically obscured X-ray...
Using new APEX and JCMT spectroscopy of the CO 2-1 line, we undertake a controlled study cold molecular gas in moderately luminous Active Galactic Nuclei (AGN) inactive galaxies from Luminous Local AGN with Matched Analogs (LLAMA) survey. We use spatially resolved infrared photometry LLAMA 2MASS, WISE, IRAS & Herschel, corrected for nuclear emission using multi-component spectral energy distribution (SED) fits, to examine dust-reprocessed star-formation rates (SFRs), fractions star formation...
ABSTRACT We report on our combined analysis of HST, VLT/MUSE, VLT/SINFONI, and ALMA observations the local Seyfert 2 galaxy, NGC 5728 to investigate in detail feeding feedback active galactic nucleus (AGN). The data sets simultaneously probe morphology, excitation, kinematics stars, ionized gas, molecular gas over a large range spatial scales (10 pc 10 kpc). contains stellar bar that is driving along prominent dust lanes inner 1 kpc where settles into circumnuclear ring. ring strongly star...
We present new near-infrared VLTI/GRAVITY interferometric spectra that spatially resolve the broad Br$\gamma$ emission line in nucleus of active galaxy IRAS 09149-6206. use these data to measure size region (BLR) and estimate mass central black hole. Using an improved phase calibration method reduces differential uncertainty 0.05 degree per baseline across spectrum, we detect a signal reaches maximum ~0.5 between continuum. This represents offset ~120 $\mu$as (0.14 pc) BLR centroid hot dust...
ALMA observations have revealed nuclear dusty molecular disks or tori with characteristic sizes 15−40 pc in the few Seyferts and low -luminosity AGN that been studied so far. These structures are generally decoupled both morphologically kinematically from host galaxy disk. We present of CO(2–1) CO(3–2) gas transitions associated (sub-) millimeter continua nearby Seyfert 1.5 NGC 3227 angular resolutions 0.085 − 0.21″ (7–15 pc). On large scales, cold shows circular motions as well streaming on...
Abstract The Galactic Center black hole Sgr A* is the archetypical example of an underfed massive hole. extremely low accretion rate can be understood in radiatively inefficient flow models. Testing those models has proven to difficult due lack suitable probes. Radio and submillimeter polarization measurements constrain very close event horizon. X-ray observations resolving Bondi radius yield estimate roughly four orders magnitude further out. Here, we present a new, indirect measurement...