Enhanced exoplanet biosignature detection from an interferometer addition to low resolution spectrographs

The physics of molecular vibration causes absorption spectra of atmospheric molecules to be a group of approximately periodic fine lines. This is fortuitous for detecting exoplanet biosignificant molecules, since it approximately matches the periodic sinusoidal transmission of an interferometer. The series addition of a 0.6 cm interferometer with a dispersive spectrograph creates moire patterns. These enhance detection by several orders of magnitude for initially low resolution spectrographs. We simulate the Gemini Planet Imager integral field spectrograph observing a telluric spectrum of native resolutions 40 and 70 for 1.65 and 2 micron bands– too low to resolve the fine lines. The interferometer addition increases the detectability of the molecular signal, relative to photon noise, to a level similar to a R=4400 (at 1.65 micron) or R=3900 (at 2 micron) spectrograph.First author draf