Daily Reports

Observers on-site: Maite Beltrán, Anaëlle Maury, Andrés Zuleta, Rodrigo Álvarez and Angel (AoD). Dave, Carlos and Jean supporting on-site (Tuesday, maintenance slot).

Operators: Gloria (day shift) and Sergio (night shift)

Jan 28th, Tuesday

14:00-16:00; Angel. No system check. NIKA2 and subsystems in good shape. Very bad weather (collateral effects of the storm Herminia; Ivo is coming). EMIR checks of high-frequency signal of external calibrator pending.

16:00-19:00; Rodrigo. Clear skies and tau_225GHz~0.15 after the last storm. Taumeter's external box wiped. Deicing system at work.

19:00-02:00: Anaëlle & Andrés. Sergio inspected the telescope from the platform (~19:30 LT). Ambient temp. -10C. Hard ice block on the upper third of the subreflector. A thumb-thick ice layer on the lower-half of M1. Telescope stopped.

Jan 29th, Wednesday

02:00-06:00; Angel: Ice on M1 and M2. Deicing active. Telescope stopped.

06:00-13:00; Maite: Antenna still stopped at 06:00. Deicing active all night but not properly working in some sectors (e.g., 8 and 3). Sergio moved the antenna to sun rising direction and waiting. Opacity at 0.3 and rising. \\

- 08:00: Cloudy skies, opacity 0.3. Waiting. Still ice on the bottom side of the antenna.

- 12:45: Ice almost melted. Wind gusts 15 m/s. Opacity 0.26.

- 13:00: We will start with test on EMIR.

13:00-19:00: Rodrigo: tests using t07, pointing, onoff_psw. Antenna parked due to high winds (14:00).

16:00. Testing pointing t07, bad results, parking antenna.

19:00-02:00: Anaëlle & Andrés. Snow and wind. Telescope parked.

Jan 30th, Thursday

02:00-06:00; Angel: Snow storm, high wind with a brief stop at ~01:30 (LT). Ambient temp. -9C. Deicing fully working, except for sector 8 (see below) mainly and some sections of the sub-reflector cell. Waiting for a sunny morning for defrosting. Light fog at the end of the shift.

06:00-13:00; Maite: Stopped snowing but we are in the clouds. Deicing working, waiting for the Sun. Temperature -10C.

- 12:00: Still plenty of ice on antenna surface. The wind does not allow to use the platform to clean the secondary.

13:00-19:00; Rodrigo. Antenna still parked.

19:00-02:00; Anaëlle & Andrés: Fog and wind. Telescope full of ice, impossible to clean: parked.

Jan 31th, Friday

02:00-06:00; Angel. Wind speed dropped enough to allow the cleaning of secondary cell, sub-reflector and legs from the platform. Thanks, Sergio. Telescope cleared, finally (02:45). Deicing switched off. Wind speed 12-13 m/s (from OSN anemometer; ours is frozen, as well as the vane). Relative humidity sensor is frozen too (reading blocked at 100%). Tau_225GHz~0.16.

- Tuning E0+E2 with EMIR for testing beam geometry after deicing and the external calibrator. FWHM 12" x 13" (1.2 mm) and 26" x 27" (3.3 mm). Some unexplained spikes on spectra of the EC tests (see the Operator report). DJ suggest a new test but with single Rx configuration.

- 05:00: Switching to NIKA2, total power. Bad KIDs: 24/3/35. Tau_225GHz~0.17. Quite stable: p2p variations +/- 1 Jy/b (2 mm) along focus sequences. Project 189-24, 1 repetition.

06:00-13:00; Maite. Clear skies, opacity ~0.2. Finishing 189-24 in TP. Starting polarization @ 07:15

- 07:30: Skydip (scan 20250131s55), pointing and beam map-pol on 3C286 (s57). Beam 17.6"x17.7". No focus needed. Calib_1

- 08:50: Starting with project 145-24. Source G16.59. Opacity 0.15. 1 Repetition

- 10:15: Pointing+calib_1 Focus+Pointing+Calib_1 on 3C286, elev. 33

- 10:45: Project 145-24, another repetition on G16.59. Opacity ~0.15

- 12:15: Pointing, focus, and calib_1 on 3C454. Opacity 0.12

- 12:40: Problems with the spindles of antenna (first since we started observing). Stopped observations for a while. Antenna stowed for security.

13:00-19:00; Rodrigo: Pointing on Uranus, and 3C454.

- 17:00: observing project 135-54, last iteration of NGC7538 done. The anemometer is working again.

- 18:00:pointing and calib1_scan 3C454, calibrations on CRL2688, MWC349, MGC7027 (scans 140-142). Skydip (scan s143). Pointing on Uranus, then moving to 128-24

19:00-02:00; Andres: Hello world. Clear skies, stable atmosphere. Opacity ~0.11. Starting with project 128-24, source L1551.

- 21:50: Last iteration of L1551 done. Changing to nikaw-24 account

- 22:10: Calibrations finished, moving to project 015-17, source NGC1333, 2 reps.

- 00:30: Changing to nikaw-24 account for calibrations.

- 00:40: Starting with project 136-24.

Feb 1st, Saturday

02:00-06:00; Angel. Tau_225GHz~0.18, quite stable atmosphere.

- Finishing 3rd round on L1482 (136-24), when target reached El. = 30 deg. + end calibration.

- Next science target (project 189-24 only for current LST) too low for observing.

- Taking this opportunity to test the external calibrator (EC), this time with single Rx configuration. Three single scans with EC = off-on-off, for harmonics 15 (232.5 GHz) and 17 (263.5 GHz). The effect of the EC is clear:

- 03:30: Switching to NIKA2 again, polarimetry. Bad KIDs: 21/3/40. Tau_225GHz~0.17. Quite stable: p2p variations +/- 1 to 2 Jy/b (2 mm) along focus sequences. Beam map-pol on 3C286 (scan 20250201s38).

- 04:30: Changing to NIKA2, total power. ad KIDs: 25/5/39. Tau_225GHz~0.18. Very stable. Project 189-24, 1 repetition on CTRS27.