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Daily Reports

IRAM staff at Pico:

OoD until Tue. 13th morning: Gloria Liñan (day), Joaquin Santiago (night)

OoD on Aug. 13-20: Enrique Lobato (day), Pedro Martinez (night)

Rx & Astro: Dave John, Carlos Duran, Miguel Sanchez, Pablo Torne, Angel Bongiovanni

OoD on Aug. 20-27: Joaquin Santiago (day), Sergio Amaya (night)

Relevant conditions at starting:

• The M1 coating works have not been finished at all. Paint touch-ups will be carried out on selected panels, starting on week 36.
• An improvement of air pipes, wiring, sensors, and control systems of the vertex is being finished by Rx team this week. The styrofoam membrane was relocated to the standard position before the NIKA2 observations. No petals have been installed yet in the vertex. Some pieces of foam layers need to be replaced between the petals and the styrofoam membrane.
• For this run, we adopted the lateral focus corrections [mm] obtained in the last NIKA2 pool week (12-19/3/2024): 1.90 /direction X, -0.78 /direction Y.
• 15:30 (LT): Last NIKA2 cooling down steps (DJ): turning on amplifiers of 1 mm arrays. No evident PT noise. Bad KIDs (window closed): 16, 1, 25 (ar 1, 2, 3)
• 20:20 (LT): Opening NIKA2 window, El. 60 deg. Waiting for a final T_MC stabilization (172 mK). Bad KIDs: 30, 3, 43 (ar1, 2, 3)

August 12th, Monday

21:10 - Miguel, Angel: Starting with tau225GHz~0.45; a drop is expected. Max. wind speed ~6-8 m/s. DAQ restarted—bad KIDs: 31, 4, 35 (ar 1, 2, 3). The NIKA2 pointing model is not updated. The first pointing try was on 1741-038. The only issues initially were a bad indent in the make_IMBFITS_nika.py code and a high deviation of the source in El. (~80") in the very first map. The latter issue was fixed after repositioning M5 & M6 (JS).

Relatively stable atmosphere over the night, with several short periods of instabilities/opacity spikes, especially at the beginning of the observations. Sidelobes max. values are well contained in maps at mean elevations, that is, about what was reached after the lateral focus session held in the last NIKA2 pool week (12-19/3/2024): <6% at 2 mm and <12% at 1 mm. Bad scan (tracking deviations >20%) although wind speed was <6 m/s: 20240812s169. Flux calibration scans on NGC7027, CRL26088, and MWC349. Beam map on 2251+158.

23:50 - High elevation scans (azel system) revisited after ASSSA commissioning using NIKA2. The maximum scan speed allowed (i.e. under the current NCS capabilities) as a function of elevation is as follows. Scan with invalid antenna traces: 20240812s199. Maybe because the El. limit allowed by NCS was reached. For the time being, any attempt must be limited to El. = 89 deg and the following max. scan speeds:

[Comment: What is limiting the maximum scanning speed ? Is it pako or is it the new drive ? <CK>]. The limitations live in the NCS (not in paKo) and they will be changed asap. A ticket related to this issue will be opened (cf. Minutes of the coordination meeting held on Aug. 19th) <AB>

Summary of calibration scans:

• Valid calib_1scan maps:

• Valid beam map:

August 13th, Tuesday

00:00 - Angel: starting with flux calibrations on Uranus and Neptune; stable atmosphere during the period. Tau_225 GHz < 0.35, max. wind speed < 11 m/s. Beam map on Uranus at 05:30 (LT). Bad scans (tracking deviations >20%): 20240813s1, s2, s7. Wind speed was between 10 and 11 m/s in these cases.

06:15 - NIKA2 session finished to give a chance to complete EMIR calibration sequences on Uranus & Mars, as well as to continue the works at the vertex.

22:40 - Miguel, Angel: works on vertex finished (DJ, CD, PM); resuming NIKA2 observations. Fairly stable. Flux calibrations on NGC7027 and Neptune.

Summary of calibration scans:

• Valid calib_1scan maps:

• Valid beam map:

August 14th, Wednesday

00:00 - Angel: continuing calibrations on Uranus. Tau_225 GHz ~ 0.3-0.4, max. wind speed < 4 m/s. Looks stable. Occasional opacity spikes around 05:30 (LT), just when the beam map on Uranus was running (scan 20). Flux calibration scans on Neptune, Uranus, Mars (apparent size: 6.1"), and the triad NGC7027, CRL26088, MWC349. Bad scan in the middle of a focus sequence on Mars (tracking deviations >20%): 20240814s64.

08:15 - After flux calibration maps on Uranus and Mars (scans 45 & 47)- the telescope was sent to 0851+202, at ~12 deg. from the Sun position, for a first light experiment about the reaction of the telescope after painting as seen by NIKA2. Kept there for ~1h with FWHM/flux measurements every ~10 min. Then, the calib_1scan on Mars and Uranus were repeated (scans 74 & 76). A summary of the results of this test in 2 mm band is shown below:

Mars before Sun exposition (calib_1scan; El. 64.8 deg.):

Uranus before Sun exposition (calib_1scan; El. 72.2 deg.):

0851+202 - Direct all-dish Sun radiation on M1 (pointing scans):

Mars after Sun exposition (calib_1scan; El. 74.3 deg.) and focus correction:

Uranus after Sun (calib_1scan; El. ):

At the position of 0851+202, the background <rms> was a factor ~1.3-2 (ar 2) and ~1.5-3 (ar 1) higher than values obtained at the position of Mars or Uranus. The beam geometry is not significantly distorted during the test. FWHM values ​​in Uranus and Mars remained within reasonable limits after refocusing.

10:00 - NIKA2 session stopped. Control of the telescope passed to OHB until ~16h (estimated) by agreement, for the installation of a new version of the tracking control loop in the ACU and appropriate testing.

16:30 - 17:50 The OHB team installed the new version of the ACU's control loop. Although Tau_225 GHz ~ 0.6 and unstable atmosphere, we did some preliminary tracking tests for ~1.5h using focus sequences with NIKA2, with peak wind speed between 6-9 m/s. Tracking profiles after that intervention are consistently better than the previous ones. Overshooting effects at the beginning of sub-scan segments no longer appear. Below is an example of the tracking profile -as seen by PIIC- before the HBO intervention (scan 20240814s10, El. ~43.5 deg., max. wind speed 3 m/s) and after it (scan 20240814s90, El. 46.2 deg., max wind speed 7.5 m/s). Sub-scan segments are defined between each pair of red and green vertical lines:

The improvement looks clear. More tests with different wind regimes and telescope attitudes are necessary. PT is working on the data compilation and the analysis of the tracking profiles. The next steps would be aimed at reducing the overhead between consecutive segments.

Summary of calibration scans:

• Valid calib_1scan maps:

• Valid beam map:

August 15th, Thursday

No observations are scheduled. National holiday.

August 16th, Friday

04:30 - Angel: DAQ restarted—bad KIDs: 29, 2, 39 (ar 1, 2, 3). Tau_225 GHz ~ 0.4, peak wind speed < 3 m/s. Starting with focus on Uranus; stable atmosphere in the l.o.s. Hexapod got stuck several times during the session (scans 19, 41, 66). It was necessary to restart NCS services a couple of times after canceling focus sequences. Beam map on Uranus. Then, a series of flux calibration scans on NGC7027, Neptune, Mars, Uranus, and GL490 (just in case) were done.

Observations of Mercury (apparent size: 11"; angular distance to the Sun: 7 deg.; Sun avoidance is set to 5 deg.) were also tried. Flux fractions retrieved for Mercury are about 41% (MB & AP). To be examined. High background RMS levels (e.g. a factor ~5 higher -at 2 mm- than the obtained one on Uranus position) in PIIC-QL maps. Gaussian fittings do not show signs of saturation. The telescope was there for about 1h. Continuing with flux calibration scans on Uranus, alpha Ori, Mars, and CRL618. The atmosphere becomes unstable starting at ~13h. Opacity is increasing steeply. On the other hand, except for alpha Ori, no more flux standards are available at reasonable elevations. Stopping NIKA2 session at 14:15 (LT).

22:40 - Angel, Pedro: DAQ restarted—bad KIDs: 29, 2, 36 (ar 1, 2, 3). Tau_225 GHz ~ 0.4, peak wind speed 3-5 m/s. Fairly stable. Flux calibration scans on the triad NGC7027, CRL26088, MWC349. Beam map on Uranus.

Summary of calibration scans:

• Valid calib_1scan maps:

• Valid beam maps:

August 17th, Saturday

04:30 - Angel, Pedro: DAQ restarted—bad KIDs: 29, 2, 39 (ar 1, 2, 3). Max. wind speed ~7-8 m/s until ~07:30. Then, it dropped to peaks of ~3 m/s. Quite stable atmosphere. After focus/pointing on Uranus, we tried to test the effects of the damage in M4 with/without an absorption mask prepared by CD & DJ, for out-focus scans on Uranus (results in progress). After that, a new beam map on Uranus and a skydip were launched, followed by flux calibration maps on NGC7027, CRL26088, MWC349, Neptune, and Uranus.

08:00 - Miguel takes over for a calibration session with EMIR.

Summary of calibration scans:

• Valid calib_1scan maps:

• Skydip: scan 20240817s28
• Valid beam map:

August 18th-22nd

No NIKA2 observations were scheduled in this period.

August 23rd, Friday

12:30 - Angel (remote), Joaquin/Sergio: Agreed in a staff meeting in the morning to give priority to calibration observations with NIKA2 to fill the observation gap of 10h < UT < 21h. Wind speed < 9 m/s; tau[225 GHz] ~ 0.25. DAQ started. Impossible to lower the count of bad KIDs from ~190 in arrays 1 and 2 when working on the resonances. The atmosphere seems to be unstable. Checking crates for these arrays anyway. Bad KIDs counts with the NIKA2 window closed: 28, 2, 24. Window reopened and DAQ restarted. Bad KIDs counts: 196, 4, 168 (ar 1, 2, 3). Window closed again. Switching to Het. pool account, project 085-24 (EMIR E0+E1). Unable to get a decent pointing in both bands (anomalous refraction). Giving up. Telescope parked at 15:10 (LT).

August 24th, Saturday

14:00 - Angel (remote), Joaquin/Sergio: Wind speed < 5 m/s; tau[225 GHz] ~ 0.78. The Telescope has been parked since ~1h ago, when Het. pool observations of project 021-24 (GP) were suspended when pwv_l.o.s. > 15 mm; awful pointing in E0 band. Waiting for any improvement. It is difficult to produce any progress on calibration data with NIKA2 under these conditions.

August 25th, Sunday

13:00 - Angel (remote), Joaquin/Sergio: Unstable atmosphere. The telescope was parked just before the beginning of this shift, except for periodic tests (JS & SA) with pointing scans with EMIR (3 mm). Signs of anomalous refraction. No NIKA2 scans. Resuming EMIR-E0 pooled observations at 21:15. PT takes over at 22:00.