Early Types

A Survey of the HI in Early-Type Galaxies

Danielle Lucero

The ATLAS3D project has very successfully provided a zero redshift baseline, against which one can investigate the evolution of galaxy global parameters with redshift, to trace galaxy evolution back in time. New facilities are now coming online (e.g. APERTIF, ASKAP,  MeerKAT) which will allow us to extend this effort to dense environments than can be explored in the nearby universe, and to increasingly higher redshifts to explore the time evolution of the structure of early-type galaxies.  

The survey has two main science goals

  •  We aim to study of the cold gas content, kinematics, and morphology of the early-type galaxies in and around the COMA Cluster and Perseus-Pisces Supercluster.  The outskirts of Coma and Perseus-Pisces offer significantly different local and global cosmic environments than those in which the ATLAS3D galaxies are embedded.  These two over densities are much more massive clusters with a much richer variety of substructures in their outskirts, providing a wider leverage to study environmental influences in these galaxies (e.g. ram pressure, galaxy-galaxy harassment).  Simulations based on ATLAS3D detections show that APERTIF will be able to directly detect early-types out to a redshift of 0.05.  The APERTIF pointings will be sensitive enough to reach a  redshift of z=0.26 where SDSS still provides optical redshifts for early-type galaxies.  Therefore, we also intend to study the cosmic evolution of the gas content of early-type galaxies by considering stacking exercises out to this redshift.
  • Use the broad band of APERTIF (300 MHz) over the frequency range 1150 - 1400 MHz (redshift 0 - 0.3) combined with the large FOV to perform blind searches for HI in early-type galaxies in order to carry out an Atlas3D like survey out to higher redshift in both the shallow and medium deep surveys of APERTIF. 


Design: Kuenst.    Development: Dripl.    © 2021 ASTRON