The Pan-Andromeda Archaeological Survey (PandAS)

PI: Alan McConnachie, Herzberg Astronomy and Astrophysics Research Center, Victoria, Canada.


The Lambda-Cold Dark Matter hierarchical paradigm is robust to large scale observables, and it is on galactic scales that our understanding of the cosmological evolution of matter is most incomplete. Many of the predicted features of galaxies, such as faint satellites and diffuse stellar haloes, are extremely low surface brightness (> 31 mags per sq.arcsec ). The Milky Way, M31 and M33 are therefore the only three large galaxies in the Universe which can currently provide robust tests of, and constraints on, many fundamental predictions of galaxy formation models. We propose the Pan-Andromeda Archaeological Survey (PAndAS), which will obtain g and i imaging of over 300 sq.degrees of the M31/M33 sub-group. PAndAS will provide the first panoramic view of galaxy haloes over a volume of ~15 million cubic kpcs, and will be complete to 32 - 33mags per sq. arcsec. PAndAS will provide the deepest and most complete panorama of galaxy haloes available, and will be used to compare to and constrain cosmological models of galaxy formation over an order of magnitude in halo mass. It will be unrivaled by any other extra-galactic wide field survey and will become a benchmark study of near field galaxy formation. The legacy value of PAndAS - for M31, M33, the Local Group, dwarf galaxies, globular clusters, stellar populations, galaxy formation and MW structure - is immense. It will become the primary reference dataset for all subsequent studies of the stellar populations of these galaxies, and will remain so into the era of Thirty Meter Telescopes and beyond. This survey is only possible for the M31/M33 sub-group, and it is only possible using the unique capabilities of CFHT/MegaPrime.


The Pan-Andromeda Archaeological Survey (PandAS) is a CFHT large program that was allocated 226 hours of observing time on MegaCam. The program was executed during the 2008A to 2012B semesters.

The data can be downloaded directly from the CADC using the following URLs:
Access all PandAS data at the CADC.
Raw data only.
Processed data only.