Close AGN Reference Survey (CARS)

 Active Galactic Nuclei (AGN) are powered by the accretion of material onto super-massive black holes at the centre of galaxies. In the current paradigm for galaxy evolution they represent an important phase in the galaxies life since the enormous energy release will couple to the interstellar medium and most likely influence the conditions for star formation. AGN have been studied over decades now at multiple wavelength and along almost the entire history of the Universe. However, spatially resolved information to study the link between the AGN and its host galaxy are often not available or technically unfeasible in particular at high redshift.

The Close AGN Reference Survey (CARS) aims to provide the most detail view on a sample of 40 nearby unobscured AGN (0.01<z<0.06). It is nothing less to establish the reference data set for AGN host galaxies that in particular observation of high-redshift AGN will be compared.  CARS will be unique as we will systematically combine spatially resolved observations across the entire electro-magnetic spectrum from X-ray to radio for a representative sample of AGN. This is only possible by combining many different observatories and using state-of-the-art instrumentation. The project started by acquiring panchromatic optical integral-field spectroscopy with the 2nd generation instrument at the Very Large Telescope called Multi-Unit Spectroscopic Explorer (MUSE). Deep NIR and optical ground-based imaging exists or will be taken for the entire sample. A large number of different other observations are planned to complete the multi-wavelength coverage with a minimum of spatial resolution. The list below given an indication for the data we plan to obtain:

  • optical IFU spectroscopy with MUSE over 1'x1' FoV (taken)
  • deep ground-based and optical and NIR imaging (taken or in preparation for observation)
  • deep Chandra X-ray mapping of galaxies with evidence for hot gas outflows (taken for 2 objects as pilot)
  • spatially resolved molecular line diagnostics and kinematics (planned)
  • VLA 21cm and continuum observation for atomic gas distribution and kinematics (approved)
  • SOFIA FIR line mapping of [CII] and [OI] with FIFI-LS and FIR imaging with HAWC+ ([CII] observations approved )
  • AO-assisted NIR integral-field spectroscopy to resolve the gas and stars with <200pc resolution (approved)
  • UV continuum and LyAlpha imaging with HST (planned)


By combining all those data set will allow to tackle a large range of science question related to the AGN-host galaxy connection ranging from AGN outflows, the conditions and fade of star formation, detailed physics of the molecular, atomic, ionised and hot gas phase, to characterising the BH mass - bulge relations for a large AGN sample.  This Website provides an overview data and the science projects pursued by the team. In the future it will host dedicated data released of the data and high-level data produces as the survey continues to be productive.