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Daily Reports (2026/10/20-27, NIKA2 run 81, Cryo run 93)

Observers on-site: Philippe André, Samuel Crowe, Jean-François Lestrade, Kaiyi Du

AoD: Miren

Operators: Sergio, Mario

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).

• When conditions are unstable and it is unclear whether project observations make sense at all, calibrations may be accounted to the pool account.

Book-keeping of important scans

We ask you to please keep track of focus sequences (as much as possible) and beam maps (always). Thanks.

Focus sequences

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

• Focus sequences
  Scan nr	Target	Ar2	Ar1	Ar3	Polarized?	Notes
  20261020s44-48	1830-211	1.35	1.04	1.02	no	starting at 1mm
  20261020s74-78	K3-50A	1.40	1.13	1.13	no	scatter A2
  20261020s101-105	Uranus	1.51	1.03	1.03	yes
  20261021s9-13	3C454	1.64	1.14	1.17	yes
  20261021s28-32	Uranus	1.48	1.17	1.2	yes
  20261021s59-63	0316+413	bad	1.05	1.03	no	started 1.14mm
  20261021s77-81	1226+023	bad	bad	bad	no	started 1.05 mm; realized we were very far out of focus
  20261021s82-86	1226+023	0.7	0.51	0.51	no	started 0.5 mm
  20261021s94-98	1641+399	bad	0.4	0.4	no	started at 0.5 mm
  20261021s123-127	1226+023	bad	0.6	0.55	no	started at 0.5 mm
  20261021s139-143	1226+023	bad	0.9	0.8	no	started at 0.5 mm
  20261021s146-150	K3-50A	bad	0.8	0.8	no	started at 1 mm
  20261021s164-168	K3-50A	1.12	0.74	0.79	no	started at 0.8 mm
  20261021s185-189	1928+738	1.7	1.2	01.22	no	started at 1 mm
  20261021s213-217	Uranus	1.62	1.15	1.17	yes	started at 1.2 mm
  20261022s17-21	Uranus	1.69	1.30	1.32	yes	started at 1.15 mm
  20261022s28-32	Uranus	1.75	1.23	1.25	yes	started at 1.30 mm
  20261022s48-52	0316+413	bad	1.01	0.98	no	started at 1.25 mm; huge scatter in arr2 focus fits
  20261022s58-62	0851+202	bad	1.3	1.4	no	started 1.00 mm; large scatter so we ran it again
  20261022s63-67	0851+202	1.6	1.2	1.2	no	started 1.3 mm
  20261022s78-82	0851+202	0.98	0.75	0.75	no	started 1.2 mm
  20261022s94-98	1633+382	0.91	0.67	0.67	no	started at 0.75 mm

Beam maps

Similarly, if any beam maps (total power) are taken:

• Beam maps (99 sub-scans)
  Scan Nr	Target	Focus	Notes

Similarly, if any beam maps (polar) are taken:

• Beam maps (95 sub-scans)
  Scan Nr	Target	Focus	Notes

October 20th, 2026, Tuesday

All observers arrive at the telescope.

16h20 - 19 LT, Kaiyi & Miren:

• 16h20 LT: end of maintenance. Very cloudy and opacity around 0.44, doing system check with EMIR.
• 17h27 LT: We did some repetitions on 030-26 (EMIR).

19 - 1 LT, Jean-François: Now opacity is around 0.35 and stable with p2p atmo fluctuations less than +/- 2 Jy/beam but 3 spikes on the taumeter during the session although sky looks fairly clear. Move to NIKA2 and project 093-26 and did 9 targets (cal_1scan). Then Observe secondary calibrator MWC349 (20261020s83) and a skydip (20261020s84). Then Miren switch to polarimetry with HWP for project 084-25: source G094.6028 with calibration scan on 3C454 before and after, we add a calibration scan on Uranus that is now above 40deg.

Focus did not change significantly during the session (1.04-1.13). Pointing offsets are large (15") but consistent thru the run.

October 21st, 2026, Wednesday

1 - 7 LT, Philippe: Opacity (tau225) fluctuating between ~0.4 and ~0.3. Observed 1 repetition on G094.6028 and 1 repetition on G100.38 for project 084-25. Did a calibration on Uranus (calib_1scan: 20261021s33) in polarized mode. Took 1 full repetition plus 2 of 3 scans of observe_G111a for 031-26 (stopped after 2 scans as elevation was getting quite low for polarimetry). Switched to TP (47Hz) at 6:45 LT. Did another calibration on Uranus (calib_1scan: 20261021s45) in total power (47Hz) and a skydip (20261021s46).

7 - 13 LT, Samuel: Opacity (tau225) started around 0.3 but steadily dropped throughout the morning to around 0.2. Started with project 082-26 observing NGC4449. Took 4 full repetitions of 2 scans each on NGC4449, then switched to observing IC0342 for project 083-26 because the opacity was so low. Finished one full repetition of 5 scans on IC0342. Project 083-26 is now completed. Took one scan of n2edf (half a repetition) for project 092-26, before cancelling the second scan of the repetition because the opacity went above 0.3 and began fluctuating. Switched back to project 082-26 to observe NGC4449 but it was too high so we cancelled. There is no other high priority option at 47 Hz TP (and this opacity) so we switched to 23 Hz TP to observe 093-26. We started data acquisition at 13:02 local time with lost kids, array 1/2/3 = 18, 9, 24.

13 - 19 LT, Kaiyi: opacity (tau225) started with ~0.35. Started with project 093-26. We switched from 23 Hz TP to 47Hz TP at 14:48 with lost kids, Ar1/2/3 = 18,9,26. We switched to project 082-26 and completed 4 repetitions (1hr) on NGC4449. Opacity became very good, tau=0.25~0.15, therefore we changed to project 092-26, and complete one repetition. We did calib_1scan on NGC7027 (20261021s158), MWC349 (20261021s159) & CRL2688 (20261021s160). Then we switched back to project 092-26 and run one new repetition.

19 - 1 LT, Jean-François: tau225 between 0.15 and 0.1 all along the run. Project 092-26 TP 47Hz : 5 repetitions completed. At some point resonances were somewhat spread out, so Miren retuned. Move to polar mode. One Cal_1scan on Neptune in this mode. Then project 084-25 : 1 repetition on target G094.6028 with IP cal on quasar 4C454 before and after. On cal_1scan on Neptune at the end.

October 22nd, 2026, Thursday

1 - 7 LT, Philippe: Very good (clear and stable) sky conditions, with opacity (tau225) ~0.15 throughout the shift. Observed B-FUN (015-17) polarimetry project: 2 repetitions of observe_b213_polar before transit, 1 repetition of observe_ngc2024n_polar near transit, and 2 repetitions of observe_b213_polar after transit. Did a calibration on Uranus (calib_1scan: 20261021s218) in polarized mode.

7 - 13 LT, Samuel: Clear and stable sky conditions continued from the night; opacity (tau225) ~0.15. Did a fifth repetition of observe_b213_polar and a calibration on Uranus (calib_1scan: 20261022s39) in polarized mode. Did a final calibration scan on Uranus (calib_1scan:20261022s45) in polarized mode before switching to project 043-26. Completed one full execution of observe_S284-3.pako (1 hour). We then switched to TP 47 Hz to take observations of NGC4449 for project 082-26.

13 - 19 LT, Kaiyi: Started with good sky conditions (tau225~0.12).

19 - 1 LT, Jean-François:

October 23rd, 2026, Friday

1 - 7 LT, Philippe:

7 - 13 LT, Samuel:

13 - 19 LT, Kaiyi:

19 - 1 LT, Jean-François:

October 24th, 2026, Saturday

1 - 7 LT, Philippe:

7 - 13 LT, Samuel:

13 - 19 LT, Kaiyi:

19 - 1 LT, Jean-François:

October 25th, 2026, Sunday

1 - 7 LT, Philippe:

7 - 13 LT, Samuel:

13 - 19 LT, Kaiyi:

19 - 1 LT, Jean-François:

October 26th, 2026, Monday

1 - 7 LT, Philippe:

7 - 13 LT, Samuel:

13 - 19 LT, Kaiyi:

19 - 1 LT, Jean-François:

October 27th, 2026, Tuesday

1 - 7 LT, Philippe:

7 - 13 LT, Samuel: