1. A New Approach to Galaxy Formation— The Universe Going Green
Matthew Malkan and Daniel Cohen, Physics & Astronomy, UCLA (310)
We identified the strongest emission line in the spectra of young galaxies.
A startling amount of their entire power emerges in one bright green line.
Unexpectedly, it is from doubly ionized Oxygen atoms.

2. In the “Subaru Deep Field” (SDF size=Full Moon)
We have accurate measurements of a half million faint galaxies. We selected 5161 of them seen when the Universe was 70 times smaller (ie. 11 Billion years ago). That’s good, but not a qualitative breakthrough.

3. Next we observed SDF with powerful Infrared telescopes at Hawaii and in orbit A small fraction of our redshift z~3 galaxies are detected, but….
UKIRT+WFCAM
The breakthrough comes from “stacking” our IR images at the locations of all 5161 galaxies to measure their AVERAGE brightness.
The Surprise: In one particular infrared band,
the faint galaxies are—on average—much TOO BRIGHT…:
NASA’s Spiter
Space Telescope

4. The Money Plot But— one band (dashed vertical lines)
Brightness
Observed Wavelength
Most of the light measured at each wavelength (filled circles) is starlight,
accurately described by a model of young stars (blue curves)
But— one band (dashed vertical lines)
is 2 or more times brighter.
This is the redshifted wavelength of Intense Green Light

5. Orion versus PN/Green Peas
Very hot stars make the gas in these galaxies glow
What we found,
in the Young Universe
Orion versus PN/Green Peas
What we
Expected,
From nearby
Young stars

6. A New Approach to Galaxy Formation-- Astronomy’s Future is Very Green:
Coming space telescopes will be going for this green--
NASA's JWST in 2018, EUCLID (2020), and WFIRST (2026), are designed to study galaxies in the young universe though this green O++ emission line.
Looking back to the very young Universe (500 million years since the Big Bang), this ‘green’ line is shifted even further into the infrared. These IR telescopes are highly optimized to provide unprecedented spectroscopic sensitivity to the strong O++ emission.

7. A New Approach to Galaxy Formation-- Astronomy’s Future is Very Green:
This one line will be the single most powerful probe of galaxy formation, as soon as galaxies form their first stars and supernovae to produce oxygen atoms – a whole field of studies has now been “Greenlighted”
Matthew Malkan, Prof. of Physics & Astronomy, UCLA (310)