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High resolution observations with the NIR adaptive optics integral field spectrograph SINFONI at the VLT proved the existence of massive and young nuclear star clusters in the centres of a sample of Seyfert galaxies. With the help of three-dimensional high resolution hydrodynamical simulations with the Pluto code, we follow the evolution of such clusters, focusing on stellar mass loss. This leads to clumpy or filamentary inflow of gas on large scales (tens of parsec), whereas a turbulent and very dense disc builds up on the parsec scale. In order to capture the relevant physics in the inner region, we treat this disc separately by viscously evolving the radial surface density distribution. This enables us to link the tens of parsec scale region (accessible via SINFONI observations) to the (sub-)parsec scale region (observable with the MIDI instrument and via water maser emission). In this work, we concentrate on the effects of a parametrised turbulent viscosity to generate angular momentum and mass transfer in the disc and additionally take star formation into account. Input parameters are constrained by observations of the nearby Seyfert 2 galaxy NGC 1068. At the current age of its nuclear starburst of 250 Myr, our simulations yield disc sizes of the order of 0.8 to 0.9 pc, gas masses of 1.0e6 solar masses and mass transfer rates of 0.025 solar masses per year through the inner rim of the disc. This shows that our large scale torus model is able to approximately account for the disc size as inferred from interferometric observations in the mid-infrared and compares well to the extent and mass of a rotating disc structure as inferred from water maser observations. Several other observational constraints are discussed as well.
We present CO(3-2) interferometric observations of the central region of the Seyfert 2 galaxy NGC 1068 using the Submillimeter Array, together with CO(1-0) data taken with the Owens Valley Radio Observatory Millimeter Array. Both the CO(3-2) and CO(1
We present observations of a massive star cluster near the nuclear region of the nearby starburst galaxy NGC 253. The peak of near-infrared emission, which is spatially separated by 4 from the kinematic center of the galaxy, is coincident with a supe
Using the method of integral-field (3D) spectroscopy, we have investigated the kinematics and distribution of the gas and stars at the center of the early-type spiral galaxy with a medium scale bar NGC 7177 as well as the change in the mean age of th
We present a multi-wavelength study (from X-ray to millimetre) of the nearby low-luminosity active galactic nucleus (LLAGN) NGC 7213. We combine the information from the different bands to characterize the source in terms of contribution from the AGN
ABRIDGED: A detailed 2D study of the central region of NGC5253 has been performed to characterize the stellar and ionized gas structure as well as the extinction distribution, physical properties and kinematics of the ionized gas in the central ~210p