Active Galactic Nuclei

The project focusses on the properties of the stars and gas close around the central black hole in nearby active galaxies. One aim is to understand how gas flows in from large scales to fuel the AGN; and whether the gas we see is related to the obscuring torus that, from some viewing angles, hides it.
We also want to learn more about ionised and molecular outflows by studying them close to their launching sites. This AGN feedback can drive gas out of the galaxy, and so we aim to connect these small scale phenomena to the large scale outflows seen in more luminous distant AGN. A third aspect of this work is to understand the role of star formation in the central tens of parsecs -- how old it is, and how intense -- what impact it has on the further flow of gas to the inner few parsecs.

To reach the high spatial resolution needed, we make use of Adaptive Optics, sometimes with the Laser Guide Star, at the Very Large Telescope. Because our work requires 2D kinematics of the stars and gas, we often observe with the near infrared integral field spectrometer SINFONI. For higher spectral resolution, and also to probe the stellar populations, we make use of spectra covering wide wavelength ranges from the UV to the near-IR as afforded by the echelle spectrograph XSHOOTER.

Artist's concept of an AGN / NASA E/PO, Sonoma State University,
Aurore Simonnet

 

And the NOEMA at IRAM (France) as well as APEX and ALMA in Chile provide complementary data on many molecular lines at millimetre and sub-mm wavelengths.

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