Polar-Areas Stellar Imaging Polarization High-Accuracy Experiment

A unique Astrophysics experiment is set to take place at the Skinakas Observatory, Crete, and the South African Astronomical Observatory in Sutherland, South Africa, aiming to clear the path towards the detection of the imprint on primordial light of the moment of creation of the Universe.

Called PASIPHAE (Polar-Areas Stellar-Imaging in Polarization High-Accuracy Experiment), the experiment will map, with unprecedented accuracy, the polarization of millions of stars at areas of the sky away from the Galactic plane, in both the Northern and the Southern hemispheres, and use this information to locate the best regions of the sky where astronomers can look for information from the early Universe.

PASIPHAE (named after the Minoan Queen) is a collaborative effort of the Astrophysics Group in Crete (the joint Astrophysics group at the Institute of Plasma Physics, the University of Crete, the Foundation for Research and Technolohy-Hellas, and the Skinakas Observatory) with the Inter-University Center for Astronomy and Astrophysics (IUCAA) in Pune, India (the greatest laboratory of optopolarimeter design and development in the world), the California Institute of Technology (Caltech in the US, including the Caltech Optical Observatories and the Owens Valley Radio Observatory), and the South African Astronomical Observatory.

PASIPHAE is led by Konstantinos Tassis, Assistant Professor of Theoretical Astrophysics at the University of Crete, and it is made possible by a grant by the Stavros Niarchos Foundation. It is additionally sponsored by Infosys, India, the South African National Equipment Program, and Caltech.

PASIPHAE will use unique, innovative polarimeters that are designed specifically for this purpose and are currently under development at IUCAA; and a very large amount of observing time, generously committed by the Skinakas Observatory at its 1.3 m telescope, and the South African Astronomical Observatory at its 1.0 m telescope.

The PASIPHAE polarimetric map will be used to perform magnetic tomography of the Galaxy: it will allow to deduce the 3-dimensional structure of the magnetic field and the dust that resides in our own Galaxy. This dust acts as a "veil" preventing scientists to get vital data that will allow us to probe the first instants of the Universe, as well as the, yet-unknown, physics of Gravity at unprecedentedly high densities and temperatures.

PASIPHAE will open an invaluable and vastly under-explored window to the Universe, through the study of starlight polarization. Beyond studies of the early Universe, the survey will lead to leaps forward in some of the most actively pursued areas in Astrophysics. For Astrophysics of the highest energies, PASIPHAE will reveal the optical counterparts (which are highly polarized) for nature’s highest-energy yet-unidentified sources. At the same time, the tomographic mapping of the Galactic magnetic field that PASIPHAE will enable will allow us to back-track the paths of ultra-high—energy cosmic rays (the highest-energy particles ever observed in the Universe) to identify their sources. Finally, PASIPHAE will allow us to better understand how stars themselves – the lighthouses of the Universe – are formed out of cold interstellar gas. For interstellar Astrophysics, the role of magnetic fields as a moderator for the rate of formation of interstellar clouds and stars is currently hotly debated.