Science Projects

Below we provide a list of primary science projects that the CARS team has defined as the major themes for the survey. This list is certainly not complete in terms of all aspects that can or will be studies with the multi-wavelength data set when additional observations are added.

[CII] emission in AGN host galaxies

The [CII] 157micron line is the dominant coolant and brightest line of the ISM in galaxies. It has been shown to correlate well with the star formation rate in galaxies and has been extensively used to characterize the ISM of galaxies at very high redshift with ALMA. It is still debated whether AGN can enhance or suppress the [CII] emission in their host galaxy due to their hard ionizing radiation field. We use SOFIA to map the [CII] line in CARS galaxies and compare this our MUSE and ALMA observation to understand the dominant excitation mechanism.

BH accretion vs. SFR/gas content across all host galaxy scales

In large AGN samples, a correlation between star formation rate and BH accretion rate has been often observed. With CARS we will investigate the relation between BH accretion and the SFR of the host galaxies in more detail than possible before and compare them with the predications from the numerical simulations

Comparison of different star forming tracers in AGN host galaxies

It is notoriously difficult to measure star formation rates in AGN host galaxies as most tracer are contaminated by the AGN emission. Nevertheless, it is important to measure the SFR to directly probe feedback from AGN. As an additional complication, different SFR tracer probe star formation on different timescales from a few to 100Myr. For CARS we are able to probe the SFR from various traces which may allow us to probe a recent decline or rise in the SFR within the last 100Myr.

Probing the BH mass-bulge scaling relation for AGN hosts

The black hole mass - bulge scaling relations is often seen as one fundamental properties of galaxy explained by a self-regulation of BH and bulge growth. Alternative explanations are becoming popular and the CARS data set should be able to allow to check which AGN or host galaxy parameters are correlating with deviations from the mean scaling relations to explore their main regulating processes.

Prevalence, size, kinematics and energetics of ionized gas outflows

AGN are known to exhibit powerful outflows in the ionized gas seen as blue wings in the [OIII] line profile. Those asymmetries are virtually present in nearly all AGN and the line shape properties seems to be correlated with AGN luminosity and other AGN parameters. With CARS we measure the size, kinematics and structure of those ionized gas outflows using the 3D data in a statistically meaningful way.