Cosmic Dawn: From Ground to Grace

When was the last time at typical baryon did anything exciting? Answer: Reionization! The signature event of cosmic dawn, and the first time when galaxies had a global impact on the universe around them. Reionization was a key transition in cosmic history. We have established important constraints with wide-field near infrared observations from the ground, and with deep slitless spectra from space. Roman will enable vast strides forward by combining both.