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Daily Reports (2025/10/21-28, NIKA2 run 75, Cryo run 87)

Observers on-site: Monica Rodriguez, Samuel Leclercq, Raphaël Maris, Stefano Berta and Stergios Amarantidis (AoD).

Operators: Sergio and Mario.

Shifts: 10-16 Raphaël; 16-22 Samuel; 22-4 Stefano; 4-10 Monica.

All times reported are in UTC (if not mentioned otherwise). Shifts times are local time (UTC+2).

Preparatory notes

Please, remember to use the focus value of Ar1 (roughly Ar2 + 0.65 mm, but use directly the focus Ar1 monitor if possible). Please use the custom modified focus script focusOTF-Z_2025.pako.

Therefore, importantly, when checking the quality of the beam on a pointing map to decide if a new focus is needed, it is better to do it on the Ar1 map, because that's the one focused at best.

Project D01-25 (M51) requires DAQ restarting with the run87_newSweep_M51_tp.ini file. Come back to run87_neSweep_tp.ini after observing this project.

Please fill the Table with the Ar1,2,3 focus values as follows. At best, make one table per day.

Similarly, if any beam maps are taken:

October 21st, 2025, Tuesday

15:00-22:00 [All]: Maintenance finished with no issues. DAQ started at 14:10 with 21/3/47 bad KIDS for arrays 1,2 and 3, respectively. Repeating the DAQ at 14:24 with 28/3/89. Trying to point at NGC7027 and MWC349 but the weather is too unstable (p2p~10-20Jy/beam), moving to K3-50A for pointing and focus (using the modified 2025 script). Moving for calib_1scan to MWC349, etc. Switching to project 053-25 (source 1803+784 is better for pointing/focus). One repetition of L1157B. Around 17:12 we moved to a skydip and then to the normal flux calibrators. After pointing/focus on 1803+784 we move to project 022-25. Two repetitions of Ceph-4.

22:00-04:00 [Stefano]: here follows the evolution of the night:

Mercury and Mars at sunset. Sunset.

October 22nd, 2025, Wednesday

04:00-10:00 [Monica]: Pointing, Focus and calib_1 scan in Uranus. Then project 066-25 (Source M31_inner) for 1 hr (1 round), weather started to became very unstable in the last scan peak to peak variations > 50 Jy/beam (Ar2). Then pointing and focus in Uranus, then the opacity rise to 1.0, so we stopped ~ 50 minutes. Continue with pointing, focus, pointing and calib_1scan in Uranus and Alfori. Then observe project 082-25 (Source PSz2G107) 2 rounds (~ 2hr).

10:00-16:00 [Raphaël]: Pointing Focus on f source 1418+546. Then observe project 082-25 (Source PSZ2G107) 2 rounds (2 hr). Making Skydip. Starting D01-M51 source. Changed to 47 Hz sampling rate: 15/4/37 lost KIDs. Nothing so bright around our science target so we move to 1633+382 to focus. Then back to 1418+546 and then to the science target (observed 6 repetitions of M51).
- @11:15 UT, Jean fixes a problem in the make-imbf. Yesterday the new make-imbf did not produce the imbf files of scan 20251021s171. we ran it manually, but the result was flawed. Jean fixed the manual version of the new make-imbf, that was looking for the Antenna traces in the wrong location. Thank you! The initial issue (that the automatic version did not produce the s171 files) is under investigation.

16:00-22:00 [Samuel]: Tau values have increased above the threshold of the project D01-M51 (0.4) thus we move to calib_1scan observations with the higher sampling rate of project D01-25 and monitor the weather. Pointing on MWC349 with p2p~10Jy/b, repeating + focus. Weather seems to go better in fact: calib_1scan on MWC349 gives now p2p ~ +-5Jy/b and tau=0.37... same for CRL2688 and for NGC7027 --> weather stabilized below D01-25 limits, so we iterate more on it after all. Alas, the time to point on nearby point source and run the script weather evolved just above limits. Switch back to 23 Hz acquisition. After reloading frequencies and tune: bad pix = 30/5/123 for Arr 1/2/3. Lots of lost kid on Arr3 probably due to relatively high sky fluctuations now. But conditions still good enough for project 053-25, though with a little doubt regarding the stability, p2p still < +-10 Jy/b in pointing scans preceding the series of scans on L1157.
- Below, screenshot showing the difference of response to sky fluctuation between Arr1 and Arr3: Arr3 gets x3 higher p2p response than Arr1 besides identical calibrated value for the source! (see today's regular NIKA2 meeting for the discussion about this topic).

Hello!

22:00-04:00 [Stefano]: Here follows th evolution of this shift:

@22:15 UT. While observing, I am thinking again about the different behaviour of Ar1 and Ar3 in variable sky noise. Practical example: one scan can have Ar1 sky noise peak to peak variations of 10 Jy/beam, and the same scan, same sky, same time, has a peak to peak variation in Ar3 of 20 Jy/beam. I asked myself if this could be due to a problem of calibration in Ar3 or Ar1. Last week, I have checked the extracted fluxes (in the PIIC QL monitor on the fly at the telescope) for few pointing scans and did not find any factor of two difference. I will have to check again more systematically when I have time. Note, anyway, that the calibration factors for run 75 are not available yet (they'll be determined at the end of the run or of the semester, as usual). The calibration factor we're using are those of March-June, when the Ar3 RPPs/Kidpars were missing the majority of KIDs. Therefore anything is possible at this point.

New example of Ar1 (left) and Ar3 (right) different behaviour. This is scan 20251022s209:
Ar1 (left); Ar3 (right); scan 20251022s209.

Yesterday/today I reduced the biggest scans taken during the recommissioning week (last week) and produced with the NEW make-imbf. The reduction went fine. This means that thee is no problem of non-monotonic MJD in these scans (this was spotted some time ago and was traced to some differences between old and new make-imbf and on how the new ACU traces are treated.

New make-imbf fail events:
20251022s196 is missing the Ar3 imbf (new make-imbf)
20251023s5 is missing the Ar1 imbf (new make-imbf)
20251023s17 is missing the Ar2 imbf (new make-imbf)

A friendly vulture at Pico. The view from above. Our beloved telescope.

October 23rd, 2025, Thursday

04:00-10:00 [Monica]: Pointing, focus and calib-1scan in Uranus and Alfori. Unfortunately the tau was ~ 0.5 all the time and seems to stay in that value or increase. So I decided to move to EMIR since the NIKA2 projects require tau values ~ 0.3. For EMIR I selected project D06-25 but there was a problem with band E150 (check the operator's report for details). So I moved to project 003-25 since they only require the band E090 (Source Science G229.57+00.1 ~ 60 min). At 6:00 UTC the weather improves a bit, and tau is ~ 0.4 so we moved back to NIKA2. We started the DAQ (run87_newSweep_M51_tp.ini). Bad KIDS were 24/6/91 for Ar2/Ar1/Ar3 respectively. Then observe project D01-25.

10:00-16:00 [Raphaël]: Pointing on the f source 1418+546, observe D01-25. At around 8:10 UTC the weather was unstable (p2p~10Jy/b). At 8:17 UTC, I did the 9 repetitions of the project D01-25 (Source M51) even with this unstable condition (p2p ~10Jy/b) and with a tau ~0.4. At 9:00 UTC, gain unstable condition (p2p ~ 10 Jy/b) and tau > 0.4, I decided to move to another project. I did the pointing source b 1641+399 (p2p ~10 Jy/b) and the Focus 1641+399. At 9:57 UTC (tau ~0.5), I moved to project 051-L1157B. Pointing source 1928+738 (p2p ~ 10 Jy/b). Then observe the source of project 051-L1157B (9th repetition) at 10:02 UTC. Sky not so stable so we try to point focus and finish the project 053-25. At 11:43 UTC, I pointed on the f source 1803+784 (p2p~10Jy/b and fwhm~13 for ar1) and at 11:40, I observed the source of project 051-L1157B (10th repetition). One hour after, pointing again the source f source 1803+784 (p2p ~5Jy/b). Then, at 13:00 UTC, I almost finished the project 053-25.

16:00-22:00 [Samuel]: Tau ~0.4, Ar2 p2p ~ 5 Jy/b, decide to change to a very different region of the sky: the Mouse nebula is getting close to its transit, just above 20 deg elevation! We are at the best moment to observe it, the sky condition is just below the limits set by the PI, and chances to observe it latter in the week is faint according to tau meter prediction, so let's go to project 062-25. Very low elevation, the astigmatism of the telescope is well visible on the focus scans. Sky stability is really at the limit oscillates between +-2.5 and +-10 Jy/b p2p depending on pointing & focus scans, repeat focus twice on 2 different sources (1757-24 & 1830-211) -> consistent results, and trend of tau in right direction -> go to the Mouse! The mouse appears very well already on the quick look plots. At end end of the 12 scans series, ~16;00, do a pointing, beam elongated at 1mm (Ar1 ~12*17"). Do a focus. Focus changed by only 0.07 mm ; the elongation seems to depend a lot on sky fluctuations (e.g. Ar1 ~12.9*13.9" then ~11.8*15.8" for 2 pointing in a row), maybe it's not very surprising at such low elevation... Tau ~0.35, Ar2 p2p ~ 5 Jy/b, Mouse still above 20 deg el, do a 2nd iteration on it.
At ~18:00, after pointing and focus, switch to project 022-25, maps on Ceph_4.

22:00-04:00 [Stefano]: here follows the evolution of the night:

From 22:00:36 to 22:00:49 UT error: "no data from the ACU", during scan 20251023s222. We (Sergio and Stefano) don't know how the scan is affected. AJ says it should be OK, but he and Gabriel will double check.

:-) Hello! Africa, the Moon, Mars and Mercury.

October 24th, 2025, Friday

04:00-11:00 [Monica]: High opacity (tau ~ 0.5) and increasing. Move to EMIR backup project D06-26 (Source science AICMi ~ 3 hrs). Then move to EMIR backup project 018-25 (Science source 79-C1 ~ 1.5 hrs and B213-C16-1 for 30 min).

11:00-18:00 [Raphaël]: At 8:10 UTC, we still have high opacity (tau ~ 0.5) and continue to increasing. We started the project 003-25 (Source G160.14+03.1). Continue the project 003-25 (Source G170.65-00.2). At around 10:00 UTC, the weather still has bad condition (tau~0.5), we decided to park the antenna because we have any sources of project to observe. At around 12:40 UTC Change to the nika setup because the opacity is quiet better (tau ~ 0.4). We had to wait for ~20min due to the visit of the MSc students in the receiver's cabin. We re-started the observations and DAQ at ~11:50 with higher rate of 47Hz with bad KIDS 29/5/83, respectively with the plan to move to the project D01-25. Tau is decreasing but wind is increasing with ~10% of losses due to tracking errors. Fighting to point/focus. Cannot point focus, weather stable but high wind and faint sources around our science target moving to skydip. Moving to SMA_1048+717 which is brighter but the wind is quite high (~17m/s) and its close to our source.

18:00-24:00 [Samuel]: ...

October 25th, 2025, Saturday

00:00-06:00 [Stefano]: ...

06:00-12:00 [Stergios, remote]: ...

12:00-18:00 [Raphaël]: ...

18:00-24:00 [Samuel]: ...

October 26th, 2025, Sunday

00:00-06:00 [Stefano]: ...

06:00-12:00 [Stergios, remote]: ...

12:00-18:00 [Raphaël]: ...

18:00-24:00 [Samuel]: ...

October 27th, 2025, Monday

00:00-06:00 [Stefano]: ...

06:00-12:00 [Stergios, remote]: ...

12:00-18:00 [Raphaël]: ...

18:00-24:00 [Samuel]: ...

October 28th, 2025, Tuesday

00:00-06:00 [Stefano]: ...

06:00-10:30 [Stergios, remote]: ...