Figure 2.
Schematic of the GIRMOS
instrument. Light from
individual objects within
the AO field is picked off
by GIRMOS and corrected
by an additional AO
system before being fed
into the IFS units. The
IFS units offer larger
fields of view for a given
sampling scale when
compared to existing
IFSs. This offers up to ten
times the multiplexing
gain over existing AO
spectrographs.
Additionally, GIRMOS will be the first multi-
object infrared integral field spectrograph
to offer a high spectral resolution mode that
enables key science not possible on exist-
ing AO-fed spectrographs, particularly those
relating to the chemodynamics of astro-
nomical objects. This unique combination
of multiplexing integral field spectrographs
with high spatial and spectral resolution will
make GIRMOS the forefront survey instru-
ment for a broad range of topics in astro-
nomical research.
The primary scientific questions that will
benefit greatly from the multiplexing capa-
bilities of GIRMOS are:
• Low- and high-mass star formation within
the Milky Way
• The search for intermediate-mass black
hole formation in central regions of globu-
lar clusters
• The formation process of the Milky Way’s su-
permassive black hole and its environment
• The nature of optical, infrared, radio, and
gravitational-wave transients
• Relative roles of internal processes and en-
vironment at the peak of galaxy formation
• Galaxies, black holes, and globular cluster
formation processes at “Cosmic Dawn”
October 2018
• Ultra-high angular resolution studies of
distant galaxies aided by gravitational
lensing
• Relationship between cold gas, star for-
mation, and dynamics in galaxies at high
redshift
GIRMOS will also be a powerful scientific
and technical pathfinder for the Thirty Me-
ter Telescope’s (TMT) Infrared Multi-Object
Spectrograph (IRMOS), which will be a future
second-generation instrument. While highly
ranked scientifically, a number of potential
hurdles were identified in the original IRMOS
concepts for the TMT. MOAO, which critically
relies on open-loop control, had not been
demonstrated on-sky, and the overall cost
of the AO system and the multiple spectro-
graphs was prohibitive. These concerns led
to IRMOS not being chosen as a first-light in-
strument for the TMT.
However, the landscape has now changed
with MOAO successfully demonstrated on-
sky through technical pathfinders such as
RAVEN on Subaru, led by our team mem-
bers, and infrared integral field spectro-
graphs being well-established technology
(e.g., Gemini’s Near-Infrared Integral Field
Spectrometer). Our efforts in developing
GIRMOS will build the necessary scientific
GeminiFocus
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