Attending: Nancy Chanover (NMSU), Russet McMillan (APO), Denise Stephens (BYU), Misty Bentz (GSU), Ben Williams (UW), Jamey Eriksen (APO), Sarah Tuttle (UW), John Wilson (UVa), Anne Verbiscer (UVa), Eric Nielsen (NMSU), Kevin Schlaufman (JHU), Joanne Hughes (Seattle U), Chip Kobulnicky (UWy)
The detailed site report is included below, followed by additional information discussed during today's meeting.
3.5-m Telescope and Instruments Highlights, 6/6/2023 – 6/26/2023
1) Overview
APO weather for June has been variable, with some thunderstorms and some very nice clear skies.
June has been busy so far this month. Two training groups have come and gone with the third coming in the upcoming week. Instrument teams have visited and had some successes as well. The end of June and July will be busy as we prepare for summer shutdown.
2) Operations
3.5m telescope: operated nominally over the past few weeks.
0.5m telescope: issues with camera control and instrument drivers are being investigated.
KOSMOS: has been stable since the last report.
ARCTIC: the diffuser rotator service had to be postponed; it will be rescheduled for a later date.
Agile: the clock sync card is being reset manually as needed.
Echelle: the inter-order light ratios (measure of scattered light in the instrument) are still quite good but are declining again with the warmer weather.
DIS: scattered light is improving slowly as expected, however, the blue channel is still considered by the APO staff to be poor and the red is considered borderline usable.
3) Other
Test fit of the mirror support system was done at Lowell last week and parts were left in the chamber under vacuum in anticipation of the upcoming recoating. The schedule is on track for the July/August shutdown and mirror recoating dates. Repairs and maintenance are ongoing for various site metrology units (dewpoint and dust sensors).
We normally get telescope motion errors around this time of year as the telescope warms up. The mitigation strategy that Bill and Russet devised seems to be working well as there have been no issues so far.
Regarding the Agile sync card issue described in the above report, operationally this means that the first exposure in a series may have a problem and the observing specialist would have to restart things. We are seeing this issue roughly 1-2 times per week.
For an ARCSAT update, Denise reports that FlareCam has been working great but BYUCam has not. Bill found a problem with the BYUCam filter wheel that may have been responsible for the instrument crashes, and he will test this when he has time (probably not for quite a while). Russet reported a recent potential issue with FlareCam, possibly condensation. This could be heat related given how hot it has been the past few days but it should get cooler tomorrow and this issue will hopefully go away.
We will be delivering 28 slits, 4 of each of the following widths (3 mounted positions and a spare): 0.8, 1.0, 1.3, 1.6, 2, 5, and 20 arcseconds. If anyone needs any other slit widths, let us know NOW. Sarah expects to be sending these new slits to APO in mid-August so they could be available when we come out of shutdown. For those who have had challenges with the KOSMOS bias levels: Sarah is hoping to resolve this by end of shutdown. She has a few experiments to try during shutdown and will update users as changes get made. She intends to save a backup of its current state so that it will be completely reversible if a user needs the instrument in its current configuration (e.g. to complete a dataset in a self-consistent manner).
John Wilson gave a status update on the new echelle spectrograph, which is currently in the conceptual design phase. The hope that we can have a lot of community engagement with the development of the instrument. The broad goal is to develop a replacement for ARCES, which has been a tremendous workhorse instrument for the 3.5m users for the past 20 years, to serve user needs for another 20 years.
Work is underway on a conceptual design, with the goal of producing a high throughput spectrograph that operates from 350-1000 nm using state-of-the-art techniques for building it. The nominal resolution is expected to be similar to that of ARCES: R ~ 30k or higher. We foresee a white pupil spectrograph design (most echelles in the last 20 years have moved to this) with dual arms, one for the blue portion and one for the red. This enables us to tailor the cross disepersion and camera prescriptions for both spectral ranges. We are planning an atmospheric dispersion corrector to address light loss at the edges of the bands and tip-tilt image stabilization to remove jitter introduced from both from atmospheric turbulence and telescope vibrations, along with a slit mechanism and slit viewer camera. One open question is whether there is community interest in having a 2-slice image slicer. If one imagines having a circular spot of the target at the slit, the slicer would divide the spot into 2 halves and enables us to double the resolution (with the high res mode getting to ~ 60k). The design team wants to get a sense from community regarding whether such a mode would be of interest since it has ramifications for detector sampling. Please consider this and talk to your users and provide feedback to Nancy. We also plan to develop and deliver a data reduction software suite.
In terms of current activities, we recently took one half-night to use DSSI for high cadence sampling images at the NA2 port to characterize how the image spots move around at high cadence. This allows us to say something about the predicted efficacy of a tip-tilt system down to about ~ 27 Hz. Additionally, Randy Hammond from the JHU Instrument Development Group is coming to APO in July to examine NA1 port and telescope structure. A science tiger team has been stood up and had one meeting so far; the purpose of that group is to provide guidance regarding what the community's desires are, have a place to vet ideas, etc.
As for near term goals, we are currently in the conceptual design phase and hope to have a Conceptual Design Review by the end of CY23 or early 2024. We may also have a refined survey of the user community for people to weigh in on science needs. To reiterate, the instrument development team is really interested in getting feedback and engagement from the ARC community so that they can deliver an instrument that meets the needs of the community. As a more practical requirement, the funding environment for instrumentation is challenging and we will need to develop well thought out science cases to pursue funding opportunities.
Chip indicated that having an R~60k mode would enable lots of science, for example stellar abundance work like Caty Pilachowski at Indiana University is doing. Kevin countered that for solar or giant type stars there is no scientific advantage of R~60k over R~30k.
There is no open time left in Q2 or Q3. Shutdown and recovery are potential areas of concern and programs that are scheduled immediately after shutdown are at risk in the event that we need extra engineering time at the end of shutdown.
Q3 ARCSAT proposals are due today; BYUCam will not be available in Q3. We will share updates with users if we learn any more about the aforementioned FlareCam issues. ARCSAT will not available during the 3.5m shutdown.
Nancy mentioned three items:
The June 2023 AAS meeting in Albuquerque was a success. We have new backdrops and banners for the booth, which looked really nice, and people liked the swag we gave out. The talk about APO that Nancy gave in the special session about astronomy in New Mexico was well received and generated interest, questions, and potential opportunities for new collaborations.
Please send Nancy any references for 3.5m-related publications (anything published from Jan 1 2022 to now). The deadline is July 31. Understanding the scientific usage and impact of the telescope is critical for evaluating future projects, initiatives, instrument concepts, etc., thus we need your help in updating our publication record! We are now participating in a cross-observatory analysis of scientific impact of ground-based telescopes, so it is especially important that we capture all publications resulting from APO observations. Any publications resulting from ARCSAT data are also requested. The listing should include refereed publications and student theses and dissertations (not conference abstracts unless they are peer reviewed) that made use of data acquired with the 3.5m and/or ARCSAT, published from 2022 to the present. If a paper has been submitted to a journal but has not yet completely gone through the review process, please include that as well, with the name of the journal and “submitted.”
Open action items from previous meetings:
New action items from this meeting:
None.
The August meeting, which would be scheduled for August 1, will be canceled as it will be in the middle of summer shutdown. Therefore our next meeting will be on September 5, and we will use that opportunity to discuss our return to operations in late August at the conclusion of the summer shutdown. The meeting schedule for the remainder of CY 2023 will stay on the first Tuesday of the month at 10:30 MT; let Nancy know if you have any conflicts.