Many obstacles must be overcome in seeking the Universe’s first galaxies.
These incredible cosmic distances necessitate immense light-gathering power.
Large-aperture telescopes and long observing times are required.
The expanding Universe dramatically shifts the emitted galactic light toward redder wavelengths.
Telescopes optimized for infrared and longer-wavelength views are mandatory.
JWST, even with its incredible NIRCam instrument, only identifies ultra-distant galaxy candidates.
Only spectroscopic follow-up can confirm these galactic distances.
JWST can conduct spectroscopic measurements with its NIRSpec instrument.
Through emission lines and/or the key “Lyman break” feature, JWST has confirmed many record-breakers.
But JWST spectroscopy costs time: an asset in high astronomical demand.
Thankfully, two invaluable assists to JWST science exist.
One is the ground-based millimeter/submillimeter observatory: ALMA.
Optimized for longer-than-infrared wavelengths, ALMA has unprecedented spectral resolution.
It sees uniquely faint, long-wavelength emission lines, like from doubly-ionized oxygen.
ALMA just confirmed galaxy GHZ2/GLASS-z12: the third-most distant galaxy ever.
But the second assist comes from the Universe itself.
Foreground galaxies and clusters can gravitationally lens background objects.
This magnifies and distorts their light, making otherwise too-faint galaxies detectable.
Pandora’s Cluster, Abell 2744, was recently imaged by JWST.
Many lensed candidates clearly stand out.
With spectroscopy forthcoming, perhaps more records will soon fall.
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.