Active Galactic Nuclei

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


The project focusses on the properties of the stars and gas close around the central black hole in nearby active galaxies. The 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. Outflows from AGNs, so-called "AGN feedback", may impact star formation in the entire host galaxy. We search for molecular outflows in neary galaxies and collaborate with the SHINING team to connect our work to the large molecular outflows seen at higher redshift.

We want to understand the role of star formation in the central tens of parsecs -- how old it is, and how intense -- and what impact it has on the further flow of gas to the inner few parsecs. Our work also encompasses mergers, which play an important role in the growth of black holes, especially at higher redshifts.

To reach the high spatial resolution needed, we make use of adaptive optics, 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 the stellar population analysis near galactic nuclei, we make use of spectra covering wide wavelength ranges from the UV to the near-IR as afforded by the echelle spectrograph X-SHOOTER on the VLT.

And the PdBI 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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