Finding the brightest cosmic beacons in the Southern Hemisphere

Understand

The study of absorptions along the lines of sight to bright high-$z$ QSOs is an invaluable cosmological tool that provides a wealth of information on the inter-/circum-galactic medium, Dark Matter, primordial elements, reionization, fundamental constants, and General Relativity.

• Unfortunately, the number of bright ($i \lesssim$ 18) QSOs at $z \gtrsim 2$ in the Southern hemisphere is much lower than in the North, due to the lack of wide multi-wavelength surveys at declination $\delta <$ 0$^\circ$, hampering the effectiveness of observations from southern observatories.
• In this work we present a new method based on Canonical Correlation Analysis to identify such objects, taking advantage of a number of available databases: Skymapper, Gaia DR2, WISE, 2MASS.
• Our QSO candidate sample lists 1476 sources with $i < 18$ over 12,400 square degrees in the southern hemisphere.