Jeremiah Horrocks Spring Lecture - Hunting for the Ghosts of Galaxies
Lecture by Dr Mark Norris of UCLan
In recent years it has become possible to study millions or even billions of individual stars within our Milky Way galaxy, and hence to determine how it formed in exquisite detail.
But our Universe contains hundreds of billions of other galaxies, all but a handful of which are far too distant to individually examine their stars. Is it possible for us to learn how they formed or acquired their stars with similar detail?
In this talk I will describe how the combination of computer simulations, large surveys using state-of-the-art spectrographs, and a few bright ideas are allowing us to pick apart the light of galaxies to work out how and when their stars were formed. In the process we are uncovering the ghosts of the dozens or hundreds of former galaxies that were destroyed to produce the surviving galaxies we see today.