How gravitational magnification allows us to see what we’ve never seen before.
“The problem is, you’re trying to find these really faint things, but you’re looking behind these really bright things. The brightest galaxies in the universe are in clusters, and those cluster galaxies are blocking the background galaxies we’re trying to observe.” –Rachael Livermore
To see farther than ever, we point our most powerful space telescopes at a single region and collect light for days.
The Hubble Frontier Fields program focused on massive galaxy clusters, using their gravity to enhance our sight even further.
By warping space, the light from background objects gets magnified, revealing extraordinarily faint galaxies.
The only problem? The cluster itself is closer and overwhelmingly luminous, making it impossible to tease out the distant signals.
Until now. Thanks to a superior new technique devised by Rachael Livermore, light from the foreground cluster galaxies can be modeled and subtracted, revealing faint, distant galaxies never seen before.
With Steven Finkelstein and Jennifer Lotz, Livermore has applied this technique to two Frontier Fields clusters already: Abell 2744 and MACS 0416.