FOBOS Focal Plane Configurations
There are very few limits to the configuration of the focal plane or the fiber compliment within a Starbug. For FOBOS first light deployment we expect three modes to be available.
- Single fiber multi-object spectroscopy (S-MOS): Allows for
approximately 1800 individual objects to be targeted using single fibers
each with an on-sky aperture of 0.8 arcseconds.
- Integral-field multi-object spectroscopy (IFU-MOS): Allows for
approximately 25 targets to be observed with spatially resolved,
integral-field spectroscopy. Each fiber bundle contains 61 fibers for a
total on-sky diameter of 3 arcseconds. Each fiber is fed by a microlens
cell with an on-sky aperture of a third of an arcsecond.
- Target-of-Opportunity integral-field spectroscopy (ToO-IFU): A fixed
IFU will be available at the field center at all times to allow for
rapid follow up of targets of opportunity (ToO). This ToO mode can
provide FOBOS spectroscopy of any object in the sky with only the time
required to slew the telescope.
The forward module is able to move away from the focal plane to an instrument storage position when not in use. This system allows for other instrument to continue using the instrument port of Keck. The forward module acts as the instrument card and contains the registration features needed for interfacing with the Keck telescope.