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Daily Reports (2025/12/9-16, NIKA2 run 77, Cryo run 89)

Observers on-site: Simon, Yiqing, Monica, Philippe (in remote first 2 days)

Astronomer-of-Duty, Pool Manager: Angel Bongiovanni

Operators: Joaquin, Pedro

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

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

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

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.

December 9th, 2025, Tuesday

• Focus sequences
  Scan nr	Target	Ar2	Ar1	Ar3	Polarized?	Notes
  121 - 125	1641+399	...	0.93	1.13	No	Marginal fitting for Ar2
  133 -137	2037+511	0.26	1.0	1.38	No	No so good for Ar3
  153 - 157	Neptune	1.0	...	...	No	Bad fitting for Ar1 and Ar3. Using 1.6 as a guess focus. Repeat
  158 - 162	Neptune	1.03	1.7	1.95	No
  181 - 185	Uranus	0.71	1.4	...	Yes	Bad fitting for Ar1 and Ar3. Using 1.4 as a guess focus. Repeat
  186 - 190	Uranus	0.66	1.4	1.72	Yes
  199 - 204	Neptune	0.95	1.7	1.95	Yes	Reasonably Good

16:00 - 22.00 Monica: We started the observations , tau ~ 0.25 a bit unstable, no wind, very high clouds. DAQ started in total power. Bad kids (Ar1, Ar2, Ar3 / 8, 7, 29). After pointing and Focus calib_1scan in MWC349 (Scan 20251209s128) and NGC7027 (s130). Then skydip (s131). Then we move to project 152-25 (Science source WB89-152 ~ 70 min -DONE). Pointing & Focus & calib_1scan (s163) in Neptune. At 19:50 we move to polarimetry projects. New DAQ, bad kids (Ar1, Ar2, Ar3 / 17, 7, 39). Then move to project 170-25. Calib_1scan (s165). Continue with the science source (Tycho - 1 rep). See PIIC-QL sample (s170, 2 mm band) below. Calib_1scan in Neptune. move to nikaw-25 Pointing & focus & calib_1scan in Uranus.

22:00-04:00 Philippe (Remotely from Granada office): Observed a polarized focus sequence on Neptune (s199-s204) and a polarized calib_1scan on Neptune (s205), but opacity and stability were degrading, therefore switched to TP. New DAQ, bad kids (Ar1, Ar2, Ar3 / 28, 7, 73). Did 1 calib_1scan on Uranus (s209) and 1 skydip (s210) in TP. Then switched to EMIR, project 147-25. Checked reference position: neither N2H+, nor SO emission in reference position; no significant C18O emission emission either, but probably weak C18O in the off position; there is definitely 13CO, HCO+, and HNC emission in the off position used to observe the reference position in position switching --> Consider observing the reference position in frequency switching? Observed the two positions p1oh (s222) and p2oh (s2) used for internal calibration purposes, then took one pair of OTF maps (@147-25_W3OH_OTF_scX + 147-25_W3OH_OTF_scY) and started another pair (@147-25_W3OH_OTF_scX).

04:00-10:00: Simon: Important spikes on tau-meter with tau~0.38 and a wind of ~9-11 m/s, high clouds. Completed the second repetition of latest map (@147-25_W3OH_OTF_scY) after pointing and focus. Observed negative features around 88 GHz (scans 24 and 32). The VESPA data appears to have important oscillations on vertical polarization (VESPA-2). The operators know. At 05:00 considered the project as closed for tonight. We change to project 193-25 of the EMIR Backup programmes at 05:20. tau~0.35 and decreasing, wind speed of ~9 m/s and decreasing, high clouds. Pointing and focus to 1226+023 were successful but we detected an anomaly possibly affecting a subscan of the correlator on WILMA-4 that could affect science target for 12CO(2-1) line. FTS spectra are okay. Scans 60 and 61 show artifacts above 89.6 GHz (already reported by the operator to GP); they do not appear in following scans after re-calibration. After repetition 12 (scan 84), we evaluated a possible switch to NIKA2. Although the tau is low (~0.35), the atmospheric conditions are looking bad (thick clouds coming from the North covering ~60% of the sky) and the opacity is increasing based on the predictions. So we decided to continue with project 193-25, using EMIR.

10:00 - 16:00 Yiqing: Tau~0.35 with unstable condition and overcast sky. Continue with observing with EMIR. We switch project to 149-25 using E150, tuning results on 1253-055 look ok. Move to project test to check the pointing and focus on 1253-055, results look reasonable. Attempts to point on 2037+511 near the science target failed due to worsening weather conditions. As no other backup projects are suitable, we attempt to point on a brighter source K3-50A, results look ok, proceed to point back on 2037+511, results ok, moving back to project 149-25. Pointing on 2037+511 yields bad results, meanwhile high wind with gust > 10km/s is destabilizing the telescope tracking. Telescope sent to stop at ~ UT12:20.

16:00 - 22:00 Monica: Snowfall, high wind speed. Telescope stopped until ~19h (LT). Opacity ~0.5, wind speed between 7 and 10 m/s. Resuming observations with EMIR backup programs (project 149-25). Switching to project test. Unstable atmosphere. Tried several pointing corrections after focusing (EMIR E1: 140.1 GHz). Constant evidence of anomalous refraction. Instabilities increase. Parking the telescope at 21:10 (LT). 22:00-04:00 Philippe (remotely from Granada): Telescope parked in stow position. Unstable atmosphere with high opacity ~ 0.4-0.5. Very light snow. Starting again around 1:30 LT with EMIR project 147-25. Opacity tau225 ~ 0.35, but significant fluctuations preventing NIKA2 observations.