APO 3.5-m Users Committee Phonecon, 4/13/09 Attending: Suzanne Hawley, Scott Anderson, Mark Klaene, Russet McMillan, Bill Ketzeback, John Bally, Bruce Gillespie, Michael Strauss, Jon Holtzman, Remy Indebetouw, and guests Cynthia Froning and Eric Burgh Absent: Al Harper, Jon Fulbright ********************************** User feedback, comments from institutional representatives: Princeton (Michael Strauss) - Michael felt that things were going well for PU users, but noted the recent trouble with guiding during TripleSpec use. Mark noted that the site staff are looking into the issue, which appears to be a known problem with the off-balance configuration of the instrument due to its asymmetrical LN2 storage system, which is difficult to overcome with hardware. Michael suggested that if there are predictable instrument orientations that cause problems, perhaps these could be communicated to the users and included in the documentation. Monitoring the fill status of the LN2 tank is difficult to do, and it seems that there is not yet a clear discernible pattern of fill condition vs. orientation that causes problems. Suzanne mentioned that we could revert to operating the instrument in constrained rotation angles. Russet added that we do not currently have the software tools, which are non-trivial, to predict the new rotator angle before the telescope slew command is issued. Colorado (John Bally) - John said that he had heard no feedback from CU users. Johns Hopkins - no report. Washington (Scott Anderson) - Scott had nothing new to report. Chicago - no report. New Mexico State (Jon Holtzman) - Jon had nothing new to report. Virginia (Remy Indebetouw) - Remy said that he had no user comments, and asked if he needed to solicit more UVa user input on the instrument upgrade studies, to which the answer is yes (see below). ********************************** Discussion of telescope/instruments report: Regarding the more detailed report below, Mark highlighted the onset of the annual spring winds and dust. The 3.5-m telescope participated in the recent 100-hour International Year of Astronomy webcast, and the observatory hosted an evening open house for some 90 people who were given tours of the telescope and views of the sky through the 3.5-m telescope and ARCSAT, although the weather was largely uncooperative. Michael asked where the open-house participants were from, and Mark said that most were from Otero County and west Texas, although one couple had come from Illinois to see APO and the telescopes. The telescope and instruments have been trouble-free during the period. The new NIC-FPS fan-out board and the NIR etalon are soon to be tested at CU. The array power issue on TripleSpec is under study, using spare power supplies and controllers. Agile is unchanged, and still available at NA2. APOLLO is running well, and its new gravimeter has been installed in the cone room under the telescope. The new direct-drive system components are being fabricated for installation during the summer shutdown. ************************* 3.5-m Telescope, Instruments, and CIF Projects Highlights, 3/01/09 through 4/10/09 Mark Klaene 0) Overview Spring winds have arrived with their associated high-dust events. This has affected a couple of nights of observing, but mostly because of the high winds rather than elevated dust levels. We participated in the "100 hours of Astronomy" webcast on April 3rd from the 3.5-m control room. We also held our first-ever open house on April 10th, using a half night of engineering time for public viewing with the 3.5- meter, and eyepiece viewing with ARCSAT and the NMSU 1-meter telescope. 60 people had made reservations for the tours. 1) Telescope Telescope operations have been generally smooth, with improved pointing and tracking. No significant telescope issues arose this past month. We continue to work on network conversion and hot- swappable backup computers. 2) Instruments DIS, SPIcam, and Echelle are fully operational. A set of Stromgren filters arrived and were placed in holders. NIC-FPS has been operational with no problems. The new fan-out board is being constructed; the new board will be tested at UVa and CU, and then a plan for its installation will be established. We hope to integrate and test the new board during the summer, but CU commitments to HST/COS may delay the installation schedule. Our spare Leach controller is at CU for testing the etalon. TripleSpec has been operating with a borrowed Leach power supply so we can monitor the array power dropouts. Agile is still available at NA2. APOLLO remains operational with some recent runs yielding significant lunar returns. A gravimeter has been installed in the cone room beneath the telescope, and it is producing useful positional information. The aircraft transponder receiver array is also working quite well. 3) CIF projects The direct-drive project is well on its way--nearly all components have been ordered and drawings have been sent to the machine shops. The current plan is to install these during the long engineering shutdown in August. The upgrade project includes direct-drive motors with new axis controllers and encoders for az and alt. We are also looking at replacing the current fiducial system with a tape encoder, initially on the altitude axis. ********************************** Imaging camera study: Cynthia Froning presented the status of the study to upgrade our visible-light imaging capabilities. Not many comments were received from a general call to the community for input, so Cynthia has been in touch with SPIcam and other users directly. There seems to be no obvious consensus on what upgraded capabilities the users want, so the study is concentrating on two possible designs with various options. Most users desire a larger field of view, which can be as large as 7 to 9 arcminutes with the existing baffling at NA2 or the Agile port. One of the options involves replacing the CCD and electronics with a detector that has more, and smaller, pixels and lower read noise. The other option is to provide multi-color simultaneous imaging capability. Cynthia will produce a preliminary report this month that details the two design paths and options, and a second report in June with cost and schedule projections. Suzanne asked about the fast- guiding camera design used at Calar Alto, and Cynthia said that she had looked at tip-tilt and "lucky" observing techniques, but to implement fast-guiding would be expensive and would need to be justified by a compelling specific science case; it is not clear that fast guiding is desired for general imaging requirements, and the cost- benefit issue is a problem. Jon Holtzman said he had looked at data from Fastcam which showed, in simulations, that the potential benefit was modest, although the data were taken in white light. Jon wondered what would be predicted if we were to use comparable I-band images. Bill said that there is no filter holder in Fastcam, but a filter could be mounted in front of the focal reducer if one wanted to obtain these data. Suzanne mentioned that if other users have additional opinions or different ideas, they should speak up now before a decision is taken on a path forward. ********************************** Echelle upgrade study: Eric Burgh has approached the primary users of the echelle and has gotten recommendations from several people. The key desired improvements are lower read noise, better blue response, higher throughput and resolution, and smaller pixels. The spectrograph has numerous vacuum-glass uncoated surfaces, and with today's broadband coatings, an improvement in efficiency of ~28% is achievable, according to Eric (but Jon Holtzman thought that earlier studies of this predicted a nearly factor of two improvement; this needs more investigation). The detector could be replaced with an e2v or Fairchild device, yielding ~2 electrons read noise with 15-micron pixels. The smaller pixels would also provide an improvement in resolution from the current value of 33k to 54k, although it was pointed out that the slit-width constraints might mitigate this gain. The mirror coatings are probably in good shape, having lived in a soft vacuum all these years. The concept of replacing the echelle grating with something more efficient is probably difficult due to space constraints in the instrument. There was no strong user sentiment to completely rebuild the echelle (e.g., split the red and blue into two channels, add image slicers, etc.). There was some discussion of who within ARC has any knowledge or memory of what the inside of the instrument looks like, and the names of some people were passed on to Eric for future contacts. Bruce and Jon asked what the RV performance level the echelle could be attainable with any or all of these upgrades, and the answer is that this needs further study. Mark suggested thinking about taking the echelle off the telescope and feeding it with a fiber, which would enable use of the NA1 port by other instruments. Suzanne said that the Users Committee members should canvas their users one last time for input to this process. Eric should complete his proposal, and encourage current and potential users to think harder about what upgrades to the echelle would be compelling to make. ********************************** User accounts on Newton: Suzanne talked about the accounts that are set up on Newton for visiting APO users to look at their data while on site. These are institution-wide accounts (e.g. uwobserver, puobserver), but these accounts sometimes are set up in a personal ad hoc way by an on-site observer that makes it difficult for subsequent users and the APO staff to use after that visitor leaves APO. She proposed that there should be a "return-to-default" protocol employed when the visiting user is finished with a user account during their visit. We could add more console-only logins, but we don't want a large number of off-site accounts active on Newton. Jon recommended that users who visit the site often could bring their own temporary setup scripts. We are looking into putting a policy in place to make these user accounts return to a default state. ********************************** Telescope scheduling process: Suzanne and Russet sent a write-up of the 3.5-m scheduling process to the User Committee members, and asked the committee members to read the screed and advise if it is ready to send to the general community and be posted. She will send it to the institutional schedulers in any case, and eventually it will be posted on the scheduling web page. ********************************** Miscellaneous [added in proof]: Suzanne forgot to mention that Jon Holtzman submitted a white paper to the Decadal Survey, titled "Apache Point Observatory: Facilities, Operations, and Partnerships", which can be downloaded at http://www7.nationalacademies.org/bpa/Astro2010_Position_Papers_byTitle.html Suzanne thanks Jon and the other authors for putting this together and getting it posted. ********************************** ACTION ITEMS: [open from previous months]: ==>ACTION: Suzanne and Russet to write a draft description of our scheduling process for eventual user dissemination. STATUS: Completed, closed this meeting. [new actions from this meeting]: none ********************************** Next meeting: The next Users Committee phonecon will be on Monday, 11 May, at 8:30 AM Pacific Time. The agenda and other materials will be sent to the committee members during the preceding week. APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 1130 in the apo35-general archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-general/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-general@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO