Event Details

The Remarkable Assembly History of Elliptical Galaxies

Abstract: Once considered the simplest morphological class with smooth surface brightness profiles and homogenous old stellar populations, elliptical galaxies continue to reveal surprises. I will present the results of several comprehensive spectroscopic campaigns of what are considered to be the precursors of present-day ellipticals seen at redshifts up to and beyond 2. Good signal to noise absorption line spectra are capable of probing the stellar kinematics and stellar populations in early examples providing valuable insight into the assembly history of passive galaxies. I will discuss several puzzles that have emerged from such data including how the compact precursors (or `red nuggets’) grew in physical size but hardly in stellar mass, and why early massive examples display rapidly rotating stellar disks in contrast with local examples.

Prof. Ellis will present the results of several comprehensive observing campaigns of what are considered to be the precursors of present-day elliptical galaxies seen at earlier cosmic times, at redshifts up to and beyond 2. Spectroscopic observations with the largest optical and near-infrared telescopes are capable of probing the motions and populations of stars in early examples of these galaxies, providing valuable insight into the assembly history of passive galaxies. Several puzzles that have emerged from such data will be discussed, including how the compact precursors (or `red nuggets’) grew in physical size but hardly in stellar mass, and why early massive examples display rapidly rotating stellar disks in contrast with local examples.