febrero 10, 2010

Hoy en el coloquio: Franck Müller (IAC, España)

12:00 pm en el Auditorio Paris Pishmish

VLT/SINFONI high-resolution integral field spectroscopy of nearby AGN: revealing the properties of the nuclear star formation and the obscuring torus


"I present results from a survey of nearby AGN using the adaptive optics assisted integral field spectrometer SINFONI on the VLT. These data enable us to study at high angular resolution (~0.08") the distribution and kinematics of the stars, molecular gas and ionized gas in the central regions of active galaxies. Our observations show strong evidence for recent, but no longer active, nuclear star formation. The intense starbursts were probably Eddington limited and hence inevitably short lived, implying that the starbursts occur in multiple short bursts. The data hint at a delay of 50-100 Myr between the onset of star formation and subsequent fueling of the black hole. We suggest, based on the spatial distribution, kinematics, and column densities that the molecular gas observed is spatially mixed with the nuclear stellar population and is likely to be associated with the outer extent of any smaller scale nuclear obscuring structure. The molecular/dusty structure on these scales may be dynamic since it is possible that the velocity dispersion of the gas, and hence the vertical disk height, is maintained by a short, massive inflow of material into the nuclear region and/or by intense, short-lived nuclear star formation."

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