ULTIMATE: a deployable multiple integral field unit for Subaru

Abstract

ULTIMATE is an instrument concept under development at the AAO, for the Subaru Telescope, which will have the unique combination of ground layer adaptive optics feeding multiple deployable integral field units. This will allow ULTIMATE to probe unexplored parameter space, enabling science cases such as the evolution of galaxies at z ∼ 0.5 to 1.5, and the dark matter content of the inner part of our Galaxy. ULTIMATE will use Starbugs to position between 7 and 13 IFUs over a 14 x 8 arcmin field-of-view, provided by a new wide-field corrector. All Starbugs can be positioned simultaneously, to an accuracy of better than 5 milli-arcsec within the typical slew-time of the telescope, allowing for very efficient re-configuration between observations. The IFUs will feed either the near-infrared nuMOIRCS or the visible/ near-infrared PFS spectrographs, or both. Future possible upgrades include the possibility of purpose built spectrographs and incorporating OH suppression using fibre Bragg gratings. We describe the science case and resulting design requirements, the baseline instrument concept, and the expected performance of the instrument.

A conceptual design study for Subaru ULTIMATE GLAO

“…The conceptual design of the multi-object IFU spectrograph (M-IFU) has been conducted in collaboration with Australian Astronomical Observatory (AAO). 5 The conceptual design assumes 8−13 fiber bundle IFUs with 1.18 × 1.18 arcsec 2 FoV for each, which are attached underneath of the wide-field corrector optics installed at the Cassegrain focus and are deployable anywhere on the focal plane at the Cassegrain focus using robotic positioners, called Starbug, developed by AAO. The fibers from the IFUs will be connected to any near-infrared spectrograph, although we consider MOIRCS spectrograph mode in the conceptual study.…”

ULTIMATE-Subaru: Wide-field Near-infrared Surveyor with GLAO at Subaru telescope

“…To fulfill the requirement from the science cases with the ULTIMATE-Subaru, we are planning to install a wide-variety of narrow/medium band filters especially in K band as well as regular broad-band filter set (YJHK) in NIR. The conceptual design of the multi-object IFU spectrograph (M-IFU) has been conducted in collaboration with Australian Astronomical Observatory (AAO) 5 . The conceptual design assumes 8-13 fiber bundle IFUs with 1".18 x 1".18 FoV for each, which are attached underneath of the wide-field corrector optics installed at the Cassegrain focus and are deployable anywhere on the focal plane at the Cassegrain focus using robotic positioners, called "Starbug", developed by AAO.…”

The MANIFEST prototyping design study

“…While a single fibre mounted in a ferrule is used in TAIPAN, for MAIFEST each Starbug requires an image slicing IFU that comprises a fibre bundle (that may have 7 to 61 fibres) mounted in a fibre array fixed to an air-spaced microlens array pair. Some development of a similar concept has already occurred as part of the AAO Ultimate [23] project (see Figure 2), though this must be further explored in the MANIFEST CDS. The multi-fibre payload also implies a modification of the connector system.…”