Resolved Structure and Kinematics of the Nuclear Regions of Nearby Galaxies

Program lead: Torsten Böker

Program duration: 18 hours

The nuclei of galaxies and their immediate vicinity are unique laboratories for a number of complex physical processes. Observing a small number of selected nearby galactic nuclei with the integral field units (IFUs) of both NIRSpec and MIRI (jointly with the MIRI European Consortium GTO team) will allow us to study them in unprecedented detail over the entire near- and mid-infrared spectral range (0.7 – 28.5μm). The unrivaled sensitivity and continuous wavelength coverage offered by the combination of JWST and NIRSpec+MIRI will provide access to a multitude of diagnostic spectral features. Mapping these over the central few hundred pc with the unique spatial resolution of JWST (~0.1”, i.e. a few pc for nearby galaxies) will break new ground even for these already well-studied objects.

We propose to observe six nearby galactic nuclei that are selected to represent archetypical examples for various classes of nuclear environments. The specific science goals therefore differ from target to target, but can be broadly summarized as follows:

• Identify any hidden active galaxy nucleus activity in heavily obscured nuclei through the presence and distribution of IR coronal lines;
• Map the kinematics of stars and different gas phases in the central few hundred pc in order to establish their dynamical status, and to constrain the nuclear mass concentration;
• Identify embedded star clusters and determine their ages and masses;
• Constrain the 2-dimensional star formation history via spatial variations in the stellar populations;
• Trace spatial variations in the amount of dust extinction, and the present-day star formation rate and efficiency;
• Map the ionization structure of the interstellar medium to identify the various physical processes at work, and to quantify their relative importance.

Observations and targets: