General Astronomy

Large Scale Structure of the Universe

Large Scale Structure

By this time you should be realizing that the universe is a bit bigger than your home planet, solar system, etc.

The amount of ‘real estate’ keeps getting larger, but is there a pattern or structure at the largest scales?

Building Blocks

• Stars are collected into clouds or clusters or galaxies– The Sun is just one of the 200 billion

or more stars in the Milkyway Galaxy• Are there larger building blocks?

The Home Galaxy

From An Atlas of the Universe by Richard Powell

The Local Group

The Milkyway is a member of a grouping of galaxies, spirals, irregulars, dwarf ellipticals. This is known as the Local Group. It is dominated by the Milkyway and the Andromeda Galaxy

From An Atlas of the Universe by Richard Powell

A 3D view gives a better pictureThe Local Group

ClustersThe Local Group is being attracted by the gravity of an even larger grouping of galaxies.

The nearest cluster of galaxies is the Virgo Cluster. It is composed of about a 1000 galaxies and it is likely that, in time, the Local Group will be absorbed (cannibalized?) into the Virgo Cluster.

Just the local neighborhood

The Virgo Cluster and the Local group are just the "smaller" structures.

Several hundred clusters are gathered into the Virgo SuperCluster.

Virgo SuperCluster

From An Atlas of the Universe by Richard Powell

Neighboring SuperClusters

From An Atlas of the Universe by Richard Powell

Here is a map of just some of the superclusters

If we look at a 'slice' it appears as if some structures are forming.

Walls and voids spotted by knots where the superclusters are located.

The Observable Universe

From An Atlas of the Universe by Richard Powell

At the largest scale, there appears to be a filamentary structure.

Hubble Ultra Deep FieldThe Hubble Ultra-Deep Field (HUDF) is an image of a small region of space in the constellation Fornax, composited from Hubble Space Telescope data.

It is the deepest image of the universe ever taken, looking back approximately 13 billion years (between 400 and 800 million years after the Big Bang)

Zoom in on a small section

Hubble Ultra Deep Field

Galaxies – over 10,000 in the HUDF!

Welcome to the Universe…