Southern Astrophysical Research (SOAR)
telescope. The results were excellent.
Also in the south, we continued to modify
the cooling arrangements for the top-end
control computer; the warmer ambient
temperatures on Cerro Pachón have caused
problems with condensation on the cooling
lines in the past, causing us to lose telescope
time due to high humidity. The modifications
are designed to increase the flow rate to the
top end, thus enabling the temperature of
the cooling water to be reduced. Despite the
loss of summit access for three days due to
a spate of bad weather, we got back on sky
on schedule — a considerable achievement
reflecting the planning and effort that the
whole team puts into these shutdowns.
GMOS-S CCDs update
Work is complete on two major quality issues
with the GMOS Hamamatsu CCDs at Gemini
South (see a detailed review of progress on
this issue starting on page 32). The “saturation effect,” which produced banding artifacts on images with saturated pixels, was solved by a video
board upgrade. Charge smearing
effects, which we had also identified as an intermittent (and hard
to reproduce) problem, were not
convincingly identified; we could
not pinpoint a particular cause in
our investigation inside the detector cryostat, but the readout cable
on the affected chip was replaced
just in case. The smearing effect is
now at a level so low that it will not
affect any conceivable science observation. We have released an update to Gemini’s Image Reduction
and Analysis Faciity (IRAF) which
is capable of handling data from
the new video boards and includes
significant improvements to the
GMOS data reduction examples.
January 2016
Figure 4.
Rehearsal for the
Gemini South
M1 recoating:
Preparing to
lift the dummy
mirror.
Visiting Instruments
Gemini continues to welcome visiting instruments. After an absence of a few years,
Phoenix (high-resolution near-infrared spectrograph) returns to Gemini South in 2016A.
Also in the south, we will host a first run for
the dual-band Differential Speckle Survey Instrument (DSSI). Watch the Call for Proposals
pages for these and future opportunities.
You may also have noticed that GRACES,
our high-resolution spectroscopy capability
realized by sharing CFHT’s ESPaDOnS Spec-
2015 Year in Review
GeminiFocus
Figure 5.
GMOS-N g band zero
point as a function of
time. The various mirror
coatings and CCD
installations are marked
with vertical dotted
lines. Far right is the
recent uptick due to the
recoating of M2.
39