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Attending: Nancy Chanover (NMSU),

Joanne Hughes (Seattle U), Eric Nielsen (NMSU), Aleksandr Mosenkov (BYU), Jamey Eriksen (APO), Caleb Wang (UW), Sarah Tuttle (UW), Mukremin Kilic (OU), Kevin Schlaufman (JHU), Bill Ketzeback (APO), Eric Bellm (UW), Ben Williams (UW)

We started by introducing Caleb Wang, a new mechanical/optical engineer recently hired into the Telescope Engineering Group at UW. Welcome, Caleb!

• Wyoming
• BYU
• Washington - nothing to report (sent by email)
• Colorado
• UVa
• FGCU
• Seattle
• Georgia State
• Oklahoma
• JHU
• NAPG
• NMSU

The detailed site report is included below, followed by additional information discussed during today's meeting.

3.5-m Telescope and Instruments Highlights, 10/3/2022 - 10/31/2022

0) Overview

APO is no longer under any staffing or indoor masking restrictions from the State of New Mexico due to COVID. The COVID vaccination policy for ARC/APO has not changed.

Weather for October has continued transitioning to fall-like.

October had no classes scheduled to visit, there was one visiting instrument (NAIC) from NMSU mid-month.

1) Telescope

Telescope is behaving mostly as expected. As the nighttime temperatures continue to drop we expect to see the seasonal issues with motion errors pop up. Those will be mitigated with adjustments to the motion control loops.

2) Instruments

KOSMOS: Internal calibration flux levels have been adjusted and exposure times are set/liked.

DIS: Servicing was completed for both cameras. Focus is good; scattered light is increasing slowly on the red camera but is expected to turn around and improve some over the winter (if it follows the historical pattern). The blue camera scattered light trend is less clear at the moment. Our best guess is that it will stabilize and hopefully turn around and improve.

TripleSpec: Cold, operational and performing nominally.

Agile: Cold, operational and performing nominally. There is a known issue with missing observatory and WCS cards from the headers that we are trying to track down. This problem seemed to originate about the time we converted and moved the hub35m to a new server.

Echelle: Echelle inter-order light ratios are excellent.

NICFPS: The instrument is performing nominally with the occasional need to reset the controller due to corrupted images, and previous cautions about rotator angle.

ARCTIC: Cold, operational and performing nominally.

3) ARCSAT: Switched to Flarecam in late October, currently in use.

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After nearly a year of KOSMOS usage on the 3.5m we are now planning to remove it from shared risk category. Going forward it will be offered to our users as a standard facility instrument. We do still have a punchlist of issues that we're working on, but after having met to discuss those items it was decided that nothing on the list impeded us from moving it off of shared risk. We are aware that the bias level appears to be changing, and the associated controller issues are still being worked on. There are also still some deliverables we are waiting for, i.e. the new slits. Over the next several months we will be reaching out to KOSMOS users who have exercised the instrument for different types of targets (extended source, faint limit, etc.) to help us understand the ramifications of some of the known instrument issues on their data.

Our meeting about the status of KOSMOS highlighted the fact that APO does not have a standing definition of shared risk and how to transition an instrument off of that status, so as an output of the conversation over the next month we will be putting together a document that defines shared risk and the expected path that takes an instrument through commissioning to becoming a facility instrument.

Note added in proof regarding the issue of the wavelength coverage of the blue center slit: Currently the blue grating on KOSMOS in the central position covers 3800-6600 A, so the red cutoff is very close to Halpha. This setup is not ideal for observing magnetic targets, which have Zeeman splitting of the Halpha line. The high slit position shifts the wavelength coverage to 4150-7050, which is good for Halpha, but now misses some of the higher order Balmer lines. So the question was asked whether it would be possible to have another slit position that would cover the range from 4000-6800 A, or something like that. UC reps: please query your users to determine if there are additional needs for this capability.

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The ARC Board of Governors meeting is on Monday November 7.

The January 2023 AAS meeting will be 8-12 January in Seattle. There will be lots of UW users there, and hopefully many from other ARC institutions and lease partners as well. The abstract deadline for the meeting is Tuesday October 11! We discussed options for doing something special for APO or ARC users. Last month the UC reps were asked to poll their users to see if they would be interested in an APO event (e.g. a meal or reception one evening) during the AAS meeting. The response was moderately enthusiastic, so Nancy will continue to explore options. We will definitely have an APO booth in the exhibit area, so in a month or two Nancy will be looking for volunteers to help us staff the booth. Stay tuned!

Open action items from previous meetings:

• Nancy: start investigations re: short wavelength throughput (climate data, other facilities). Status: OPEN. No news. Old news: Nancy reached out to some colleagues at other observatories to ask about short wavelength performance degradation of their optical coatings. She got some names from Bill and will contact those individuals next. The ongoing discussions about new coatings for the primary also relate to this issue so we will determine our coatings first before continuing to pursue this line of investigation.

• UC reps: please encourage your users to submit science highlights. Nancy needs to have them all in hand by Wednesday October 26.
• UC reps: please query your users to determine whether they have a need for a slightly different wavelength range for the blue grating.

New action items from this meeting:

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The next meeting will be on Tuesday December 6, 10:30 am MST.