Comparison of Massive Galaxies at Early Times vs. Today

galaxy_comparison.jpg

galaxy_comparison.jpg

Massive galaxies today are substantially larger and more bulgy than massive galaxies 10 billion years ago. The left column illustrates the difference in size by comparing a face-on view of the massive present-day elliptical galaxy (NGC 4472) to the Hubble NICMOS image of a face-on ultra-compact galaxy from 10 billion years ago. The right column highlights the disky nature of massive young galaxies by contrasting an edge-on view of a modern bulge-dominated spiral (NGC 4594, the Sombrero Galaxy) with the an edge-on view of a massive disky galaxy from 10 billion years ago. Credit: T. Weinzirl, S. Jogee (U. Texas)/STScI/NASA/SDSS