Daily Reports (2026/02/24 - 03/03 NIKA2 run 79, Cryo run 91)
Observers on-site: Felipe Alves, Shixian Mo, Miren Muñoz (up to Friday), Li Yingxi, Miguel Sanchez (starting on Friday)
Astronomer on Duty: Stefano Berta
Pool Manager: Angel Bongiovanni
Operators: Pedro (day), Ioaquin (night)
Organization of shifts:
22:00-04:00 LT: Miren/Miguel
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
20260227s54-58
3C273
out
1.33
1.53
yes
started at 1.7 mm
145-149
Uranus
out
1.25
1.45
no
started at 1.5 mm
177-181
3C84
out
1.38
1.60
no
started at 1.6 mm
20260228s51-55
3C273
out
1.44
1.68
yes
started at 1.7 mm
113-117
Neptune
out
out
1.0
yes
started at 1.3 mm; Ar3 marginal
118-122
Neptune
out
0.72
0.94
yes
started at 0.9 mm
135-139
Uranus
0.65
1.52
1.86
no
started at 1.5 mm; Ar2 based on FWHM only
20260301s35-39
3C273
0.49
1.40
1.63
yes
started at 1.5 mm; Ar2 only FWHM; using the old make-imbf (slooooow)
91-95
3C454
out
1.27
1.54
yes
started at 1.5 mm; 2251+158; very good fit in Ar1 and Ar3
112-116
Uranus
0.0
0.90
1.12
yes
started at 1.3 mm; Ar2 based on FWHM only
131-135
Uranus
out
0.84
1.03
yes
started at 1.0 mm
156-160
Uranus
out
1.37
1.60
no
started at 1.6 mm
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 LT. Opacity ~ 0.16 and stable sky (+/- 2 Jy/beam @2mm)
- 108-25: 1 repetition on G214.5_S4_5 and 1 repetition on G206.0183
- Switched to nikaw-25 for a skydip (20260227s3)
- All sources in NIKA2 projects are too low, so we need to move to EMIR backups
- 02:00 LT: EMIR time. 3 repetitions on M51. Opacity ~ 0.17.
Friday, 27th February 2026
04:00-10:00 LT Felipe
- 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, two extras rep of M51. Observing script modified to m51_otf_260227.pako
- @6:15 LT we switch to NIKA2 pol. Lost KIDS 16/3/16. Start with project 130-25
- 130-25 four reps of B59, using 3C273 and 3C454 for the IP
10:00-16:00 LT Li
- 156-25 one reps of N68, using 3C454 for the IP
- calibrations on NGC7027 and CRL2688 (scans nr 93 and 94)
- @11 LT cloudy, but tau(225)~0.2 and good peak to peak stability, therefore we continue
- 156-25 six reps of N68, using 3C454 and Neptune for the IP
- 155-25 one rep of S106WFIL
16:00-21:30 LT Mo
- 155-25 one rep of S106WFIL
- @17:15 LT we switch to total power. Lost KIDs 17/5/24
- 108-25 one rep of G206.0183 and two reps of G222.6000
- skydip (scan nr 159)
- @19:55 LT we stop and have a ~1h pause. The sky is rather variable and the resonances are drifting a lot during these long scans. The sky opacity prediction says that tau will decrease soon, that is the sky will likely clear up. It's not worth to switch to EMIR for a short time, therefore we take a little break and wait a bit.
21:30-04:00 LT Miguel
- @21:30 LT we start observing again, using EMIR. Project 147-25
- @22:45 LT we switch back to NIKA2. Lost KIDs 25/5/38. we start observing @23:00 LT
- 108-25 two repetitions of G224.6079 (final elevation around 28 deg), 1 repetition of G214.5_S01_1 (too low elevation to try a second repetition). All sources are too low (below 30 deg) to do any useful observation so we change to EMIR @01:24 LT.
- @01:50 LT start observing EMIR project 102-25
Saturday, 28th February 2026
04:00-10:00 LT Felipe
- 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, 3 extras rep of M51. Observing script used is m51_otf_260227.pako
- @05:20 LT: stop EMIR and starting setup of NIKA2 pol. Lost KIDS: 14/4/28
- @05:45 LT: start of NIKA2 pol. observations on project 130-25. 5 repetitions using 3C273 and 3C454 (at end) for the IP. tau~0.26, very low wind
10:00-16:00 LT Li
- 155-25: three repetitions of S106WFIL using 2251+158 (3C454) and Neptune for IP characterization
- scan 20260228s87 reached El~88.4 deg! Both scans 86 and 87 had a "pre-limit" in telescope velocity triggered, plus one-two tracking alarm(s).
- the new make-imbf des not produce the imbf files of scans 87 and 89. It produces 90 regularly. Stefano makes the imbf of 87 and 89 by hand
- @14:15 LT the 155-25 target is now in a big thick white cloud. We move to Neptune for calibrations and re-focus. Difficulties at re-focusing (warm temperature outside and strong Sun hitting the dish). Thick clouds all around, except at the Sun's and Neptune's position. The focus keeps changing very quickly. Skydip (scan nr 125)
- @15:30 LT we stop the telescope, because of the thick clouds and it starts snowing!!!
16:00-22:00 LT Mo + Stefano
- @20:15 LT we switch on NIKA2 again (total power). Lost KIDs 13/3/21
- 108-25 1 rep of G214.5_S0_1
- 108-25 1 rep of G222.6000
22:00-04:00 LT Miguel
- Pointing, focus and calib_1scan towards Uranus
- Pointing and calib_1scan towards ALFORI (Alpha Orionis, a.k.a. Betelgueuse)
- 108-25 1 rep of G206.0183
- 108-25 1 rep of G224.6079. Scan 155 cancelled at 23:32 LT, lost tuning. JSG retuned, 30/4/29 KIDs lost. Resumed (orthogonal angle is s156).
- 188-25 1 rep of G214.5_S0_1, 1 rep of G195.8882. We stop here as the elevation of the objects is getting too low (below 30 deg).
- Switch to EMIR. Look for 1mm pool project to exploit the sub-mm sky tonight. 01:25 LT.
Sunday, 1st March 2026
04:00-10:00 LT Felipe
- Continuing 1mm EMIR project (183-25) started in previous shift. Weather conditions are exceptional, tau ~ 0.19 and very low wind. Script currently being executed: 183-25_otf_0301.pako, with science source NGC4565.
- @5:45 LT stop EMIR and starting setup of NIKA2 pol. Lost KIDs: 13/3/17
- @06:00 LT: start of NIKA2 pol. observations on project 130-25 in excellent weather conditions. N repetitions using 3C273 and 3C454 (at end) for the IP. tau~0.15, very low wind
SB: the /imbfits/ disk is 100% full! Therefore the new make-imbf script cannot write the IMBF files and we have to proceed using the old one, which is a mess, because it's f'n' slow and we are in NIKA2-Pol. For the Murphy law, this happens on a Sunday morning at 6 a.m. Sigh!
- Consequences: until space is made,
- we'll use the Ar2 focus +0.95 if it's not out of range, or we wait for the Ar1 focus wasting some extra precious time (last day with decent weather and last chance to complete the project);
- we will not perform any pointing before calib_1scan (the IP corr scripts anyway do a re-centering);
- we will operate blindly, taking for granted that the focus won't change.
- @7:00 LT Jean makes space. Thank you so much for doing this on an early Sunday morning! Total time lost ~30 minutes waiting for the old make-imbf production.
130-25 four repetitions of B59, using 3C273 and 3C454 for IP. The project 130-25 still has one hour available, but we set it to finished for now.
10:00-16:00 LT Li
- calibrations (scans 65, 66, 67, 71, 77), skydip (scan 68)
- the new make-imbf skips scan 74. SB runs it by hand
- 155-25 one repetition of S106WFIL, using Neptune and 2251+158 for IP
@12:47 LT the power supply is off. The Diesel generators are switched on automatically. The observations should not be affected, for now. The whole ski station has no power, many people are "waiting" in the cabins and in the lifts!!!
155-25 one last repetition of S106WFIL, using Neptune and 2251+158 for IP. The allocated time of 155-25 is now completed! SB sets it to finished.
- 156-25 two repetitions on S08, using Uranus for IP
- @15:58 LT the power grid is back and the Diesel generator switches off. No consequences for the observations
16:00-22:00 LT Mo
- 084-25 one rep of IRAS 23385 using Uranus for IP
- @18:25 LT we switch to NIKA2 total power. Lost KIDs 12/4/18
- 108-25 one rep of G195.5194, G211.8773, G214.5_S6, G214.5_S4_5, and G210.1020
- @21:00 LT the wind is increasing, but we resist until the end of all 5 sources.
22:00-04:00 LT Miguel
- we let the 108-25 observations to be completed
- @22:55 LT we have to park the telescope because of the high wind.
Monday, 2nd March 2026
04:00-10:00 LT Felipe
- the telescope is parked because of wind and snow.
10:00-16:00 LT Li
- the telescope is parked because of wind and snow.
SB: the mirroring of the NIKA2 data from Granada/Pico to Grenoble is again stopped. The last transferred imbf files are of Feb 21st (Ar1 only, btw). This happens every time. I've sent to the Grenoble IT (cc Granada and other people) the usual request to restart the mirroring. This is unfortunate because causes delays in the production of the new DAFs for the full run 79 and conflicts with preparation of proposals for the next IRAM deadline (March 12th). I'm sorry for any inconvenience this might cause, but it's out of my (magic) powers to make this work smoothly once and for all.
16:00-22:00 LT Mo
- the telescope is parked because of wind and snow.
22:00-04:00 LT Miguel
- the telescope is parked because of wind and snow.
Tuesday, 3rd March 2026
04:00-10:00 LT Felipe
- Starting with 3mm EMIR project 102-25. Weather conditions are poor, currently with tau ~ 0.3 and increasing, and wind borderline high, with gusts from time to time crossing the 10m/s limit. A bit of fog with a tendency to clearing. Script currently being executed: m51_otf_26-227.pako. As weather is not good, probably we will not switch to NIKA2.
- @8:15 LT: it snows and winds are getting stronger, telescope had to be parked. Project 102-25 had 7 full repetitions performed today
Post scriptum
@09:28 LT Miguel
- the wind is getting (slightly) down, so we try to continue 102-25. One further repetition before leaving.
- @10:20 LT. End of the week.
END of the last NIKA2 W25 pool week
The last winter 2025/26 NIKA2 pool week is over. A big thanks goes to the operators for their precious help and infinite patience, the cooks for the fantastic meals, all the IRAM-ES staff for their support, and of course to You, observers... without you there would be no NIKA2 observations! See you all next time! Stefano.