GeminiFocus 2016 Year in Review | Page 45

to a satisfactory level , but the 60 Hz vibrations remained in M1 , potentially affecting other science instruments . Therefore , in mid- 2015 , Gemini upgraded the GPI cryocooler controller to a new model — one with an active damping system that measures the cryocooler ’ s acceleration and applies a counteracting one to dampen the vibrations at their source ( Figure 22 ). Measurements with GPI indicate that the new system reduces the 60 Hz defocus residual wavefront errors from about 50 nm root-mean-square ( rms ) to as low as 1 nm rms — a factor of 50 reduction !
Work on vibrations in GPI is part of a longterm program to characterize and reduce vibration effects on both Gemini telescopes . Over the next two years , we plan to install a common accelerometer system on both telescopes to permit continuous monitoring of vibration levels .
Early Use of the Gemini Observatory Archive
Early use of the new Cloud-based Gemini Observatory Archive has been healthy . Here are some initial statistics as of April 2 , 2016 .
�� �����������������������������������������ber is increasing all the time .
�� ����������������������������������������tal of 45,000 archive searches and downloaded 550 GB in 117,000 files . We ’ re currently seeing about 1,750 archive searches and about 30 GB ( compressed ) downloads per week .
�� ����������� ��� ����� ���� �������� ����� ��� ���� archive , a total of 8.6 TB ( compressed ), and 29 TB ( uncompressed ) FITS data .
Finally , don ’ t forget that in order to access proprietary data from your program you will need to register your program ID with your archive user account . See this paragraph on the help page for further instructions .
Australia ’ s Partnership in Gemini : A Retrospective
December 31 , 2015 , marked the end of Australia ’ s time as a full member in the international Gemini Partnership . Stuart Ryder , Head of the Australian Gemini Office ( AusGO ), reflects on Australia ’ s participation as a Partner over almost two decades .
Australia joined Gemini in 1998 , with the first time allocations made in Semester 2001A . Over the next 30 semesters , the Australian Time Allocation Committee received a total of 739 Gemini proposals . Of these , 440 were allocated queue time , and a further 25 were allocated classical nights on Gemini ( or Subaru via the time exchange program ). The average oversubscription factor was 2.0 . Thanks to the flexibility offered by Gemini ’ s queue mode , almost two-thirds of these programs got 80 % or more of the data they requested under the required conditions .
Following are some notable Australian contributions to Gemini :
� Development of the Near-infrared Integral Field Spectrograph ( NIFS ) and the Gemini South Adaptive Optics Imager ( GSAOI ), two of the more productive and reliable instruments on the Gemini telescopes .
� The Australian Gemini Undergraduate Summer Studentship ( AGUSS ) program . Since 2006 , the program has sponsored 23
Figure 22 . Close-up of GPI attached to the instrument support cube ( white , at top ). Vibrations from the instrument ’ s cold heads coupled very efficiently into the cube and then into the mirror cell .
January 2017 | 2016 Year in Review GeminiFocus
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