The design of GNAO is optimized for a broad range of science cases that will allow for major synergies with the James Webb Space Telescope and Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) as well as other recent and upcoming facilities like the Nancy Grace Roman Space Telescope and Euclid. The example science highlighted below is a joint summary of the science cases developed for GNAO and its primary science instrument GIRMOS.

Time domain astronomy at high angular resolution

As a queue-operated wide-field AO facility, GNAO will be a premier facility for follow-up observations of transient and multi-messenger sources. Compared to seeing-limited follow-up campaigns, GNAO’s high angular resolution offers key advantages for: 

• Characterizing transient sources against contamination of their underlying host galaxies
• Localizing transient sources in crowded stellar regions or near galactic nuclei
• Spatially resolving lensed transients
• Astrometrically comparing pre- and post-event images

A particular strength of GNAO will be the ability to rapidly follow-up transient alerts from Rubin Observatory’s LSST with greater flexibility than space telescopes. In addition to the primary rapid-response mode offered through the GIRMOS imager, the GIRMOS spectrograph will be available for spectroscopic time domain studies. 

Spatially resolved spectroscopic surveys

GNAO’s primary science instrument GIRMOS will use the GNAO-compensated science beam for multiplexed spectroscopy through up to four deployable integral field units (IFUs). GIRMOS offers a multi-IFU mode with additional Multi-Object AO (MOAO) correction within a 2-arcmin diameter probe field or a tiled-IFU mode using the GNAO narrow-field AO compensation. Key science cases for these modes include surveys of high-redshift galaxies and globular clusters, respectively. These surveys will provide unprecedented sample sizes of spatially-resolved morphology and kinematic data for galaxies around redshift 2 (the “cosmic noon”) and key opportunities to search for the putative intermediate-mass black holes hosted in globular clusters.

Multi-purpose AO facility for solar system to extragalactic studies

GNAO offers a broad range of capabilities for solar system, Galactic, or extragalactic studies. The key capabilities are 

• Flexible choice between narrow-field (near-diffraction-limited) and wide-field (enhanced-seeing) AO modes, 
• Full integration into the Gemini queue operation scheme
• Non-sidereal tracking options

Apart from the scientific opportunities described in the previous sections, example GNAO+GIRMOS science cases include

• Monitoring of giant planet atmospheres, their disks and satellites  
• Multiplicity and surface properties of icy small solar system bodies
• Multi-epoch studies of protostellar outflows and jets
• Formation and evolution of young star clusters
• Survey of ultra-compact HII regions
• Studies of galaxy nuclei and supermassive black holes
• Characterization of gravitationally-lensed systems