Apache Point Observatory
New Mexico, USA

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ARC 3.5-m Instrument News

News Worthy Items

• ARCTIC has completed its shared risk phase and is in normal observing modes. There are still a few items on a punch list of things to be completed.
• Triplespec is in shared risk mode. No progress has been made in determining the cause of failures. Recovery from the failures is also an uncertainty. Sometimes recovery is quick and other times the instrument self corrects itself just by sitting idle. See below for more information.
• As of August 30, 2013, the 3.5-m has implemented a TAI time standard in all the instrument headers. All time keywords are referenced to TAI. In an effort to make all time keywords the same from instrument to instrument several keywords are no longer being written to some instrument headers. The standard keywords are: TIMESYS, UTC-TAI, UT1-TAI, LST, DATE-OBS (TAI time at start of exposure in year-month-day-hour:minute:second format), and EXPTIME. Every effort has been made to give users the minimum number of time related keywords in which they can recreate any of the old keywords on their own in post imaging processing.

Current Status

Instrument issues which our users should be aware of before taking data. For historical information go here. For future instrumentation or planned upgrades go here.

• 2012-01-24: APO still does not recommend taking dome flats with AGILE. More information can be found here.

• 2016-04-04: No further reports on the intermitent issues since December.
• 2015-11-30: The slitviewer computer problems appear to be intermittent but are quickly resolved by the observing specialist.
• 2015-10-18: Slitviewer problems returned over the weekend. Investigating further.
• 2015-09-30: Slitviewer computer rebuild complete. The instrument is available again
• 2015-09-21: Last nights night log reported the slitviewer camera computer was experiencing problems. Investigating but until resolved the instrument is unavailable for science.
• 2014-10-13: Most recent interorder ratio plot can be found here.

• 2016-01-26: Several instrument issues have been resolved off the punch list. Quad readout is working after we have replaced the preamp boards. The larger 5 inch sloan filters an a set of 4 inch square UNM filter are available for a larger field of view from SPIcam. Holders for 3 inch and 2 inch square filters are also available for use. A Johnson-Cousins UBVRI set is expected to arrive in March.
• 2015-10-20: The Instrument is behaving well. There are a few items that users should be aware of.
• 1. Quad readout is currently not recommended due to an issue with one of the preamp boards amplifiers. Please use single mode readout.
• 2. Current filters that are available: SDSS u,g,r,i,z and UNM 4" H-Alpha set (657/3,658/3,659/3,660/3,661/3). We are currently making a number of 3 inch filter holders. Those should be available by November 1.
• 3. WCS cards have been fixed for full frame imaging but are not correct for subframing.
• 4. Aborts and stops of exposures now work.

• 2016-03-23: The dcamera shutter was swapped out with a spare. We finally saw and identified the failure mode. The bad shutter has been RMA'ed and we have a spare on order as well. Operation with the new shutter has been performing well.
• 2016-01-14: The sticky shutter on the slitviewer is still a problem. We hope to resolve it soon with an in house shutter driver.
• 2015-10-05: Sticky bit issue resolved. The instrument with both cameras is available
• 2015-10-05: Cooled the red camera again on Friday. Cool down biases looked great. However once I started putting light on the detector a sticky bit (2E14) appeared. We will have to investigate further this week. Simple resets of the electronics did not fix or resolve it. Otherwise, we were able to focus the camera by moving the actuators all the way to the forward most end of their range and moving the red collimator lens near the forward end of its range.
• 2015-08-01: Potential slitviewer shutter problem with short exposures on the slitviewer and bright stars. Vertical bleeding of stars seen in short (less than 2 second) readouts. Does not appear to be a problem with guiding.
• 2015-06-04: A new version of TUI (2.4.0) is required to display the new slitviewer. DIS Users should install this new version of TUI. Most users will find binning the slitviewer camera 1x1 is fine for guiding and display however in the event of poor seeing or slow image downloads consider switching to 2x2 mode. Users will also notice a much faster readout time and increased sensitivity for the new camera.

• 2016-03-28: The instrument was removed from the observing floor. It is no longer available for use.
• 2016-02-14: The instruent has warmed, been powered down and decabled. It is no longer available for use.
• 2016-01-26: The instrument will be decommissioned the second week of February. It will then be sent back to GSFC sometime before summer.
• 2015-10-26: Vacuum not soft. Must have been a bad fill yesterday morning. Leaving on the pump for the rest of the day and will start cooling at the end of the day.
• 2015-10-25: Inadvertantly warmed. Will put on vacuum pump tomorrow to see if it is vacuum related.
• 2015-10-16: GIFS is cold and operationsal again.
• 2015-09-12: GIFS is on the vacuum pump.
• 2015-10-09: Started warming GIFS. Will put it on the vacuum pump on Monday.

• 2016-02-22: Nicfps ION pump is having some issues near the end of its lifetime. If the instrument is rotated past +/- 100 degrees vacuum becomes soft and system temperatures begin to rise. We will be restricting rotations at NA2 until new parts can arrive (on order) and they can be scheduled for a full vacuum servicing. This may be April at the earliest. The observing specialists will restrict rotations to +/-90 degrees and can assist observers in choosing a rotation based on their targets.
• 2016-01-25: Instrument has had no reported problems at this time.
• 2015-11-30: Some resets and reboots recently due to corrupted or noisy images. Still appears intermittent. Will continue to monitor
• 2013-01-17: The instrument is currently not usable for Fowler Sampling modes > 8. NFS 8 and below still work fine.
• 2012-01-24: NICFPS still experiences intermittent failures since the fall of 2010. Please coordinate with the observing specialist for monitoring of failures and recovery modes as you take data. More information can be found here.

• 2016-02-22: Spicam will be retired this coming summer shutdown. With the successful commissioning of ARCTIC, we plan to retire spicam likely at the end of Quarter 2 or 3. An offical date has yet to be announced.
• 2015-11-02: Report from last night of images with all pixels having zero values. An instrument reset cleared the problem.
• 2015-10-20: Fiber replaced, instrument is again available.
• 2015-10-19: Bad fiber. Will run a replacement tomorrow.
• 2015-10-19: Still no answers. Could not find problem remotely with observing specialists help over weekend. Will investigate further today.
• 2015-10-17: Instrument in non-responsive. First report in nightlog of 10/15. Investigating.
• 2015-06-15: No further drop outs of ion pump controller communications. Will monitor at a less frequent rate.

• 2016-03-14: Instrument continues to operate in an uncorrupted state.
• 2016-01-25: Instrument has been in an uncorrupted state for many weeks.
• 2015-11-30: Instrument is back in its bad state.
• 2015-11-02: Report that the instruemnt behaved well last night. 1500 test darks were taken with no corrupted images. >
• 2015-10-12: The instrument is still rather intermittent. It had troubles over the weekend but middle of the night self corrected after ~100 images after a reset. It then behaved for the rest of the night.

The information on this page is up to date as of April 4, 2016. This page is maintained by the 3.5-m Telescope Engineer .