FEDReD III : Unraveling the 3D structure of Vela

TL;DR

This paper presents a 3D extinction density map of the Vela complex using Gaia and 2MASS data, revealing detailed structures, substructures, and their relation to the Vela supernova remnant, along with a catalogue of interstellar clumps.

Contribution

The study introduces a novel 3D extinction mapping method combining FEDReD and FellWalker algorithms, providing detailed morphology and substructure analysis of the Vela complex.

Findings

Revealed the Vela Molecular Ridge as three substructures instead of four.

Identified a large cavity aligned with the Vela supernova remnant.

Produced a catalogue of ISM clumps with location, distance, and dust content.

Abstract

Context. The Vela complex is a region of the sky that gathers several stellar and interstellar structures in a few hundred square degrees. Aims. Gaia data now allows us to obtain a 3D view of the Vela interstellar structures through the dust extinction. Methods. We used the FEDReD (Field Extinction-Distance Relation Deconvolver) algorithm on near-infrared 2MASS data, cross-matched with the Gaia DR2 catalogue, to obtain a 3D cube of extinction density. We applied the FellWalker algorithm on this cube to locate clumps and dense structures. Results. We analysed 18 million stars on $450~\mathrm{deg}^2$ to obtain the extinction density of the Vela complex from 0.5 to 8~kpc at $\ell\in[250\degr,280\degr]$ and $b\in[$-10$\degr,5\degr]$. This cube reveals the complete morphology of known structures and relations between them. In particular, we show that the Vela Molecular Ridge is more likely composed by three substructures instead of four, as suggested by the 2D densities. These substructures form the shell of a large cavity. This cavity is visually aligned with the Vela supernova remnant but located at a larger distance. We provide a catalogue of location, distance, size and total dust content of ISM clumps that we extracted from the extinction density cube.