Daily Reports

Because of COVID-19, only IRAM staff is allowed to observe on-site until new notice.

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Note by Stefano: It's fantastic to be back. I hope everyone will soon be allowed to come observing in person, because it's a very nice feeling. I promise I'll make this Daily report colorful with some nice photos for you, when possible.

Oct 26th, Tuesday

Always using the new sweep from now on.

Currently the adopted pointing model is the one for "summer". The latest EMIR pool showed large [pointing offsets, like the NIKA2 observations of last week, therefore here we've been wondering if it's time to switch to "winter". The issue is under investigation by Manuel (deputy station manager) and soon we'll know more.

19:00-21:00-03:00 afternoon and 1st half of the night shifts. Angel and Stefano
We start late because earlier the telescope was in the clouds. Then the sky clears for a nice sunset and for letting NIKA2 have some fun :-)
We find a small typo in the Ar3 PIIC DAFs that prevents it to process the data but we have no permissions right now to fix it. Therefore we switch off the Ar3 PIIC monitor and ask RZ to fix it for us tomorrow. We also have a small hickup with the processing the focus sequences, but it does not prevent to use the PIIC monitor anyway (restarting the PIIC monitor the problem is solved). We observe the filler program 045-21 with regular pointing and focus. Skydip in scan 20211026s109. With these conditions we don't perform any beammap nor calibrators scans.
We switch to the 47.6 Hz sampling frequency (editing the .ini file) and we restarted the DAQ. This frequency is needed by the ARSENAL time filler program (086-21). After pointing/focus, we start observing 086-21 with the 47.6 Hz sampling. Note that with 47.6 Hz sampling the data files are bigger and the make-imbf process takes longer than with the standard 23.8 Hz sampling. The PIIC monitors process the 47.6 Hz data just fine. Meanwhile the sky opacity improved to an astonishing 0.3. We give the stage to the next shift.

Little treats of the day:

Oct 27th, Wednesday (day 300)

Hélène, Annie; 03h-09h: We observed project 086-21 (ARSENAL) with 5 repetitions on A520 (one already done in the previous shift, so a total of 6 so far)and 3 repetitions on A665. We were unsure about the exact elevation limit (55 degrees according to the README, 58 degrees according to the pako interface) but did not want to take any risk and switched sources before A520 got to 55 degrees. We did a focus and a calib_1scan on Uranus, and regular pointings. The 2mm FWHM varied between 17.8 and 18.2 arcsec. Opacities remained at ~ 0.3-0.35 in the first half of the shift and then fluctuated more, between ~ 0.35 and 0.7. It was very hard to gauge the stability of the atmosphere from PIIC results, because the display is tiny.

Mónica, Brisa, Stefano, Angel; 09h-15h: We continued with project 086-21; 6 repetitions on A2218. Opacity was around 0.4 with progressively increasing instability. Pointing corrections from ~10, 9 arcsec at the morning evolved over the shift to ~15, 15 arcsec. Beam size (2 mm) about 17.5 x 18.0 arcsec with very slight variations. Stable about 65% of the time (2 to 5 Jy/beam at 2 mm). Variations of timelines reached about 17 Jy/beam for some scans. Mean noise rms (2 mm) of ARSENAL maps ~50, ext. corrected 85 mJy/beam. Stopped around 14:15 because of a sudden opacity increasing.

Isabelle, Karine, Angel, Stefano; 15-21h: we switch again to the sampling frequency of 23.8 Hz. The last scan at 47.6 is scan number 20211027s100. The sky conditions degraded a lot. Opacity was very high (generally above 0.8) with spikes up to 2! We get back on the question of switching the pointing model from summer to winter. Manuel applies some changes: starting from the NIKA2 summer pointing model, he applies a shift of 8 arcsec to the parameter P7 (offset in Elevation), such that P7(new) = P7(summer) + 8 arcsec. [NOTE: this is now done only for NIKA2]. We test this with new pointings and the El offset is now ok. The first scan obtained with this new pointing model configuration is 20211027s111. We observe 045-21, although the conditions are still poor. Stopped at 16:50 because due to very high opacity and dense fog.

21:00-03:00 Juan, Emmanuel, Stefano. tau~0.3. We observe the calibrators NGC7027, MWC349, Uranus (scans 153, 155, 158). Then we start to observe NGC1333-C2 belonging to 010-21 and perform 4 repetitions. We then switch to 199-16 and observe PSZ2-G111.6 (3 repetitions).

Today's challenge: try to take a sky flat-field with NIKA2:

Oct 28th, Thursday

Someone, Angel: 09-15h: The opacity is stable at the start of the shift so we continue for one iteration on 160-16. Then we move to E03-20 for one repetition until it's too high. Opacity and atmosphere gets unstable and we have difficulties to focus for a while. After a restart of the acquisition we move to project 086-21 for one repetition.

Oct 29th, Friday

Oct 30th, Saturday

Oct 30th, Sunday

Nov 1st, Monday

Nov 2nd, Tuesday