APRIL 2017
GHOST Taking Shape
Development of Gemini’s high-resolution
optical spectrograph GHOST — a joint effort
by the Australian Astronomical Observatory,
the National Research Council Canada-Herz-
berg, and the Australian National University
— continues to progress. As of the end of
2016, most of the Cassegrain unit’s mechani-
cal parts have been manufactured, received,
Figure 15.
GHOST integral field unit
positioner frame.
Figure 16).
GHOST Slit Viewer
mechanical assembly.
test fitted (as shown in Figures 15-17), and
partially disassembled for anodizing. The
Cassegrain unit’s mechanical assembly is
close to being completed. Most of its op-
tics have also been received, and they have
passed Acceptance Testing; optics integra-
tion will start at the end of March, followed
by electronics integration.
The final mechanical elements for the Guide
Camera assembly, Slit Viewer assembly, and
Calibration unit, have also been completed,
and we are now ready to integrate their op-
tical elements and electronics. The Guide
Camera assembly and Calibration unit are
on target for Instrument Control Software
integration in mid-May.
— David Henderson
Figure 17.
FLAMINGOS-2 Capabilities
GHOST IFU positioner
mounted in its frame on
the tilt table.
Multi-Object Spectroscopy Progress
Credits: All AAO
The FLAMINGOS-2 (F-2) near-infrared (NIR)
imager and spectrograph was designed with
multi-object spectroscopy (MOS) in mind,
but we could not commission this important
feature until now. F-2 MOS is achieved by
cutting aluminum plates (“masks”) with the
desired slitlets’ width, length, and target po-
sitions in the 6 x 2 arcminutes field-of-view
on the sky. The masks are located on the
“MOS wheel,” which locates each mask on
the telescope’s focal plane and has slots for
nine different masks.
One critical capability for MOS observations
is the ability to change masks while the in-
strument is installed on the telescope. By
addressing this important function (as we
did with this work) we minimize the impact
on the instrument-telescope alignment and
keep the camera cryogenic dewar cold, with
the detector stabilized at its working tem-
56
GeminiFocus
January 2018 / 2017 Year in Review