Tomographic Intensity Mapping versus Galaxy Surveys: Observing the Universe in H-alpha emission with new generation instruments

Understand

The H-alpha line emission is an important probe for a number of fundamental quantities in galaxies, including their number density, star formation rate (SFR) and overall gas content.

• A new generation of low-resolution intensity mapping probes, e.g.
• SPHEREx and CDIM, will observe galaxies in H-alpha emission over a large fraction of the sky from the local Universe till a redshift of z ~ 6 to 10, respectively.
• This will also be the target line for observations by the high-resolution Euclid and WFIRST instruments in the z ~ 0.7 - 2 redshift range.