Contraintes morphologiques et multi-longueurs d'onde sur la croissance parallèle des galaxies et de leurs trous noirs super-massifs.
Morphological and multi-wavelength constraints on the coeval growth of galaxies and their supermassive black holes.
Porteur CEA : E. Le Floc'h
Summary: So far the morphology of distant galaxies has mostly been explored as a secondary property of sources first selected as a function of other parameters like their stellar mass, their optical color or their monochromatic luminosity in the infrared, the radio or the X-rays. Since these selections suffer from their own biases, this has led to lots of disconnected views on the mechanisms driving galaxy formation. Our program MORPHOSTAR will aim at a less biased understanding of this problematic, with two key and original aspects: (i) we will connect the structural properties of high redshift sources (probed by their morphology) with simultaneously their stellar mass, star formation rate (SFR) and activity of nuclear accretion; (ii) we will minimize selection effects in the SFR and nuclear activity estimates thanks to the combination of a large number of multi-wavelength indicators and diagnostics (i.e., UV+IR, X-ray, radio, spectral lines). Such a global effort has never been pursued so far but we expect our approach to yield a major step forward in our understanding of structure formation, especially in the context of the parallel growth of stellar mass and super-massive black hole:
• Galaxy morphologies will be determined not only based on public ACS/HST images but also at rest-frame optical wavelengths using the WFC3 near-IR imaging. They will provide critical information on the structural properties of the galaxy stellar component at high redshift, with less biases from dust extinction compared to the ACS data.
• The star-forming activity will be quantified with the deepest far-IR observations ever undertaken with Herschel and to which we have access.
• A much less biased view on AGN activity will be obtained by combining deep X-ray data, mid-IR selections and new spectral line diagnostics.
• Detailed comparisons will be performed between the observed morphologies and the signatures expected from the state-of-the-art simulations.
Team members: Emeric Le Floc'h, Frederic Bournaud, Pierre-Alain Duc, Stephanie Juneau, David Elbaz, Romain Teyssier, Yu-Yen Chang, Anita Zanella & Anna Cibinel.