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For et al. present observations of the Eridanus supergroup
obtained with the Australian Square Kilometre Array Pathfinder (ASKAP)
as part of the pre-pilot survey for the Widefield ASKAP L-band Legacy
All-sky Blind Survey (WALLABY). The paper concludes by considering
the place of the Eridanus supercluster within the cosmic Web. The
cosmic web is a network of filaments with clustered galaxies and gases
stretched across the Universe and separated by voids. It is seen in
simulations and maps derived from galaxy redshift surveys. The so
called the cosmic flow models are represented by the observed
distribution of galaxies, peculiar velocities, and the underlying
density field. The image above shows a 3-dimensional slice of the
Universe centred at supergalactic position SGX=0 and the environment
that the Eridanus supergroup resides in. The positions of the
Eridanus supergroup galaxies are plotted against a map of the density
contrast reconstructed from the Cosmicflows-3 Catalog of peculiar
velocities. The map is obtained with the ray-casting volume rendering
technique, resulting in a smooth representation of the dennsity
contrast field ranging from most underdense (deep blue color) to most
overdense (yellow), combined with a series of semi-transparent
iso-surface polygons resulting in a sharp materialization of the
surfaces ranging. The grey surface delineates the frontier between
underdense and overdense patches of the local Universe. The model
suggests that Eridanus supergroup is currently merging/falling onto
the Fornax knot.
An interactive 3-dimensional model is also available.
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