Daily Reports (2026/02/24 - 03/03 NIKA2 run 79, Cryo run 91)
Observers on-site: Felipe Alves, Shixian Mo, Miren Muñoz, Li Yingxi.
Astronomer on Duty: Stefano Berta
Pool Manager: Angel Bongiovanni
Operators: Pedro (day), Ioaquin (night)
Organization of shifts:
22:00-04:00 LT: Miren
04:00-10:00 LT: Felipe
10:00:16:00 LT: Li
16:00-22:00 LT: Mo
Important
Focus offsets shall be measured on Ar1
Pointing offsets shall be measured on Ar2
Pool-Account usage: Accounting of observing times
Calibration observations like pointing, focus, and calib_1scan (the latter in case of NIKA2-Pol only, aimed at characterizing the instrumental polarization) which are conducted before and during project observations are part of the project time. Note that all proposals include such overheads in the time and sensitivity estimates. This holds for total power and polarimetry observations.
Other calibration observations which are important for all projects like beam maps, skydips, or calib_1scan for absolute flux calibration may be accounted under the pool account (nikaX-YY, where X = s,w and YY = year ; nikaw-25 in this case).
- When conditions are unstable and it is unclear whether project observations make sense at all, calibrations may be accounted to the pool account.
Focus and Beam maps accounting
Please fill the Table with the Ar1,2,3 focus values as follows. At best, make one table per day.
Focus sequences
Scans nr.
Target
Ar2
Ar1
Ar3
Pol?
Notes
20260224s75-79
Uranus
out
0.65
0.90
yes
started at 1.3 mm
109-113
Uranus
-0.14
uhm
+0.72
yes
started at 1.0 mm; Ar2 based on FWHM only; Ar3 with 4 points only; Ar1 with only 3 points -> re-do
114-118
Uranus
-0.17
+0.64
+0.84
yes
started at 0.8 mm; Ar2 based on FWHM only
128-132
Uranus
0.11
0.85
+1.15
yes
started at 1 mm; Ar2 based on FWHM only (marginal)
153-157
Uranus
out
1.43
out
yes
started at 1.3 mm; Ar1 only 4 points but good parabola
182-186
3C84
0.51
1.55
1.80
yes
started at 1.43 mm
20260225s8-12
3C279
out
1.60
1.86
yes
started at 1.55 mm
14-18
3C279
out
1.65
1.90
yes
started at 1.60 mm
31-35
3C279
0.67
out
out
yes
started at 0.70 mm
40-44
3C279
0.78
1.70
1.96
yes
started at 1.7 mm; Ar2 based on FWHM only
71-75
3C273
0.36
1.3
1.5
yes
started at 1.55 mm; Ar2 based on FWHM only
139-143
Uranus
out
1.2
1.4
yes
started at 1.5 mm
180-184
Uranus
0.69
1.4
1.65
yes
started at 1.7 mm; Ar2 based on fwhm only
215-219
0815+202
0.66
1.64
1.82
no
started at 1.4 mm; Ar2 and Ar3 based on fwhm only
20260226s45-49
3C273
0.29
1.32
1.54
yes
started at 1.5 mm; Ar2 based on fwhm only
70-74
MWC349
out
1.35
1.6
yes
windy; started at 1.2 mm; Ar1 based on Ar3-0.25
145-149
Uranus
out
1.2
1.45
no
started at 1.2 mm
156-160
0815+202
0.37
1.39
1.63
no
started at 1.2 mm, based on fwhm only
Similarly, if any beam maps (total power or polarimetry) are taken:
Beam maps
Scan Nr
Target
Focus
TP (99 subscans) or Pol (95 subscans)
Notes
20260225s22
3C279
1.65
Pol
Ar1
20260225s24
3C279
1.90
Pol
Ar3
20260225s37
3C279
0.67
Pol
Ar2
Tuesday, 24th February 2026
@09:30 UT the team arrived safely at the observatory
@9:30-14:00 UT: Maintenance time; we do a cuple of hours of training on Stefano's slides before lunch
@15:30-22:00 LT Mo + everyone
- we start the NIKA2 operations, with polarimetry; lost KIDS 5/15/22. The 1.5 Hz peak in the pow spec (see last week) is still there.
- Tapas log-in is not working at the beginning and PM fixes it
- few stuck scans at the start (focus sequences). Pedro fixes the problem.
- training all together
- 156-25 one repetition of N68 using Uranus for IP
- 128-25 one repetition of L1482 using Uranus for IP
- calibrations on Uranus + skydip (scan nr 20260224s125)
- 128-25 one repetition of L1482 using Uranus for IP
- 128-25 last scan repeated, so to compensate for the one cancelled on 2026/02/16 and make a round total number of repetitions
@22:00-04:00 LT Miren
- 128-25: one repetition of L1482 using Uranus for IP
- Calib_1scan on 3C84 (20260224s174), closer in elevation to L1482 than Uranus. To be used to calibrate the IP with Uranus.
- Calib_1scan on Uranus for IP (20260224s176)
- Calib_1scan on 3C273 (20260224s179). To be used to calibrate the IP with Uranus.
- Pointing, focus, pointing, and calib_1scan (20260224s188) on 3C84
- 0.25 repetitions (1/4 rounds) of L1482. Too low in elevation for more rounds.
- Calib_1scan on 3C273 (20260225s4) for IP.
- nikaw-25: polarimetry beammaps for the three arrays. Ar1 beam of 11x13 arcsec, several focus and pointings to try to solve this before the Ar1 beammap.
Wednesday, 25th February 2026
Note about using the QSOs for IP characterization:
Miren has observed calib_1scan of 3C84 and 3C273 with the same setup as Uranus (same focus, similar Elevation, same time) under 128-25, for future use. When observing (later today) other projects, we will have only the QSOs available, e.g. 3C273. We will observe them for IP characterization. At the stage of the data reduction, we can derive the intrinsic polarization properties of 3C273 using the 3C273+Uranus scans taken by Miren, and then subtract it from the 3C273 scan(s) taken together with the science target (but no Uranus) to obtain the IP (instrumental pol). See Section 6.10.1 of the next PIIC user manual release.
04:00-10:00 LT Felipe + Stefano
- we let the 3rd pol beam map finish.
- and then we are in a gap of projects that started already in the previous shift at ~00 UT. Projects 197-25 and 137-27 (Total power, filling the gap) have been completed. Therefore we are now running short of targets. We continue with some QSOs monitoring with NIKA2. Specifically, we run calib_1scans on 3C286, 3C273, 3C279, to be used to cross-calibrate their pol properties with each other. Skydip (scan nr 38)
- 130-25 five reps of B59 using 3C273 for IP (to be characterized with the 3C273+Uranus scans taken in the previous shift in 128-25), and 3C454 at the end
10:00-16:00 LT Li + Stefano
- 140-25 one rep of CloudG using 3C454 for IP
- 155-25 three reps of S106WFIL using 3C454 and Neptune (! see Section 6.10.1 of the next PIIC user manual release) for IP
- one round on the three calibrators (MWC349, CRL2688, NGC7027; scans 118, 119, 120). [We're in NIKA2-Pol, but we'll use them for the usual TP absolute flux cal]
16:00-22:00 LT Mo + Stefano
- the taumeter tau is increasing, but the peak to peak variations of the 2mm timeline (pointing scans) are still within +/- Jy/beam along the l.o.s. of 155-25 and 128-25, therefore we continue with polarimetry
- 128-25 1,5 reps of L1482, using Uranus for the IP characterization
- skydip (scan nr 174), calibration scan on Betelgeuse (nr 177)
128-25 one last rep of L1482, using Uranus for the IP characterization. The allocated time of 128-25 is now completed! SB sets it to "finished"
- @21:30 LT we switch to total power. Lost KIDs: 25/2/29
22:00-04:00 LT Miren
- 108-25: finishing the 2nd repetition on G211.8773, opacity ~ 0.26. 2 repetitions on G214.5_S6.
- At 00:15 tau is ~ 0.3 and peak to peak variations at 2mm of +/- 2 Jy/beam.
- 108-25: 1 repetition on G214.5_S4_5. All the sources of this project are too low and sources of project 126-25 are at an elevation of -30 deg, so we need to switch to EMIR.
- ~ 01:00 LT. We switch to EMIR backup projects. 147-25 project sources are already too low, so we start with project 102-25.
- EMIR 102-25: 3 repetitions on M51. Opacity ~ 0.3 and stable sky.
Thursday, 26th February 2026
04:00-10:00 LT Felipe + Stefano
- EMIR time, filling the gap. We continue the observations of 102-25 (M51): we let the rep started in the previous shift finish, pointing, focus, one extra rep of M51
- the wind is whistling through the door. Uhm
- @5:15 LT we have to park the telescope because of the wind. We'll try again when the NIKA2 sources are high enough on the horizon.
- @6 LT we switch to NIKA2 and try. Lost KIDs 11/3/23. No bump at 1.5 Hz and regular, narrow 3 Hz peak at 3 Hz (HWP rotation). Looking great!
- 130-25 two reps of B59, using 3C273 for IP (7 reps completed)
- we interrupt @8:40 LT because of the wind. We move to the direction of 156-25. Motor currents errors. We take some scans to allow Ignazio to record data for the re-definition of the alarm criteria. The situation gets better and we decide to go on trying 156-25
- 156-25 zero reps of N68, using 3C454 for the IP. At 9:22 LT we officially give up. Too much wind. At least we tried.
- @9:25 LT telescope parked
10:00-16:00 LT Ioannis (remotely)
- @11:00 LT starts the XPOL POLAMI session. But the telescope is still parked
- then follows XPOL T14-25
- @14:10 LT Ioannis starts observing for T14-25
16:00-22:00 LT Mo
- @18:00 LT the XPOL T14-25 session ends (by Ioannis).
- we switch to NIKA2 total power. Lost KIDs 16/4/17. Observations start @18:20 LT
- 108-25 half repetition of G222.6000 (one scan). Then @19:15 LT we have to stop because of the wind. We wait some time to see how the wind evolves. What a day!
- ...
22:00-04:00 LT Miren
- We resume observations at 23:40
Friday, 27th February 2026
04:00-10:00 LT
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10:00-16:00 LT
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16:00-22:00 LT
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22:00-04:00 LT
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Saturday, 28th February 2026
04:00-10:00 LT
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10:00-16:00 LT
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16:00-22:00 LT
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22:00-04:00 LT
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Sunday, 1st March 2026
04:00-10:00 LT
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10:00-16:00 LT
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16:00-22:00 LT
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22:00-04:00 LT
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Monday, 2nd March 2026
04:00-10:00 LT
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10:00-16:00 LT
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16:00-22:00 LT
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22:00-04:00 LT
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Thuesday, 3rd March 2026
04:00-10:00 LT
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