Quasars are among the most luminous objects in the universe, powered by supermassive black holes at the hearts of distant galaxies. Although they often appear as close points on the sky, determining their true three‑dimensional separation remains challenging.
A team led by astrophysicists at the University of Alberta has introduced a procedure that combines the spectral lines of quasar pairs to compute their mutual distance with greater accuracy. The approach uses both redshift information and distinctive emission features.
The method relies on comparing the observed frequencies of specific ionization lines that depend on the surrounding gas cloud. By modeling these lines, the light‑travel time between the two objects can be inferred, yielding a distance estimate.
Initial tests with simulated data indicate that the uncertainty can be lowered by up to 40 percent compared with traditional techniques. The researchers anticipate that the approach will be useful in upcoming large‑scale surveys aiming to map the cosmic web in finer detail.