Vela Supercluster Mapped in Detail Behind Milky Way’s Zone of Avoidance

Researchers have completed the first detailed mapping of the Vela Supercluster, a massive cosmic structure located behind the dense region of the Milky Way known as the Zone of Avoidance. This development provides new insights into one of the largest known superclusters in the universe.

The mapping process combined galaxy peculiar velocity data with new redshift observations to reconstruct the supercluster’s structure. The hybrid approach allowed scientists to chart the Vela Supercluster despite the challenges posed by the Milky Way’s obscuring stars and dust.

Data for this reconstruction included over 65,000 galaxy peculiar velocity distances from the CF4++ catalogue. Additionally, more than 8,000 new galaxy redshifts were collected near the southern Galactic plane, with over 2,000 high-sensitivity HI redshifts obtained from the MeerKAT telescope.

The Vela Supercluster is estimated to be about 800 million light-years from Earth. Its location behind the Milky Way’s Zone of Avoidance had previously limited observations, but the new mapping techniques have enabled a clearer view of its size and structure.

What the numbers show

• 65,518 galaxy peculiar velocity distances were used in the mapping
• 8,283 new galaxy redshifts were collected, including 2,176 from MeerKAT
• The supercluster’s total mass is estimated at 3.38×1017 solar masses
• The structure spans approximately 300 million light-years in diameter

The Vela Supercluster displays a double-core morphology, with two main cores moving toward each other. This structural feature distinguishes it from other known superclusters.

Initial identification of the Vela Supercluster occurred in 2016 through spectroscopic redshift surveys using AAOmega+2dF and SALT instruments. These early observations revealed an overdense region covering about 25 by 20 degrees of the sky.

Current measurements indicate that the Vela Supercluster contains mass equivalent to roughly 30 quadrillion suns. This mass makes it more massive than the Laniākea Supercluster and second only to the Shapley Supercluster among known structures of its kind.

The hybrid reconstruction estimates the supercluster’s characteristic radius at about 70 h⁻¹ megaparsecs. The new mapping provides a more complete understanding of the Vela Supercluster’s scale and position within the universe.

* This article is based on publicly available information at the time of writing.