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Daily Reports (2025/11/18-25, NIKA2 run 76, Cryo run 88)

Observers on-site: Tuan-Anh Duong, Fengwei Xu, Benedetta Kalemi, Sihan Jiao

Astronomer-of-Duty, Pool Manager: Ioannis Myserlis

Operators: Joaquín Santiago, Mario Cervera

Preparatory notes

Please, remember to use the focus value of Ar1 (roughly Ar2 + 0.65 mm, but use directly the focus Ar1 monitor if possible).

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

Similarly, if any beam maps are taken:

Pool-Account usage: Accounting of observing times

November 18th, 2025, Tuesday

15:30-18:00 Ioannis : Maintenance finished on time and start directly with NIKA2 observations. ~ 1hr of NIKA2 observations training with new observers (and the ones that want to refresh their memory). Started with NIKA2 total power to check stability. Tuning looks good (12/5/21 bad kids for Ar1/2/3) and pointing plus focus look consistent and stable. Sky looks stable (~ 1.5 - 2 Jy/beam at 2mm) and we decide to change to NIKA2-Pol (8/4/39 bad kids on Ar1/2/3). Start of project 084-25. Pointing, focus and calib_1scan (20251118s88) on 3C454 (2251+158), which has similar elevation with selected target (IRAS23151). Tried to do 1 rep on IRAS23151 but fog came fast and light snow started as well, so we stopped until weather gets better.

18:00-00:00 Sihan : @ 19:10 the weather is better, have a try. Sky is stable ( < 2 Jy/beam at 2mm). Restart of project 084-25. Pointing, focus and calib_1scan (20251118s107) on 3C454. 1 repetition on IRAS23151. After the scientific observation, calib_1scan (20251118s117) on 3C454. @ around 21:25 switch to total power for project 066-25.Sky is stable ( < 2 Jy/beam at 2mm). Pointing and focus on 3C454, calib_1scan on CRL2688 (20251118s125). Do skydip @ 23:55 (20251118s135).

November 19th, 2025, Wednesday

00:00-06:00 Tuan-Anh : Starting with NIKA2-Pol, good tuning (17/6/19 bad kids Ar1/2/3). Pointing, focus, calib_1scan (20251118s142) and beam map optimized for Ar1 focus (20251119s1). Then start with 015-17 (B-FUN) observations. Pointing, focus and calib_1scan on Uranus then pointing on 0333+321, 2 repetitions on NGC1333 with calib_1scan. Switch to nikas-25: pointing, focus, calib_1scan on Uranus. Back to 015-17, pointing on 0458-020, 1 repetition on OMC-3N then calib_1scan on Uranus. At last, do a beam map optimized for Ar3 focus (20251119s45) and a skydip (20251119s46). We have a very stable sky +/- 0.5 Jy/beam, tau ~ 0.15 during the shift.

06:00-12:00 Fengwei : After beam map in polarization is finished we move to NIKA2-TP mode (tuning good 15/7/17 bad kids for Ar1/2/3). Pointing and focus on 1226+023 and we start with observations of project 082-25. 1 repetition on PSZ2G229. And we switched to nikas-25: pointing, focus, (20251119s60) on 1226+023. Then we switched to 082-25. Pointing scan and then to start science scans on PSZ2G229 with 1 repetition. Pointing scan (20251119s72) on 1226+023 gives a still good focus and beam shape at both 1 and 2 mm. So we continue 1 repetition on PSZ2G229. We switch to nikas-25: pointing and focus on 1226+023 (20251119s78). Then we switched to 082-25 to do pointing and then 1 repetition on PSZ2G229.

12:00-18:00 Ioannis, Juan : Beam slightly extended (~18.5" at 2mm) so repeat pointing and focus on 1226+023. Indeed focus changed again and now the beam size is getting larger. Skydip (20251119s105) and flux calibration on MWC349 (20251119s108, s114), CRL2688 (20251119s111) and NGC7027 (20251119s118). We moved to project 082-25 after a focus in 3C286 and launch 1 repetition on PSZ2G229 (20251119s122-125 , notice last scan was cancelled) As PSZ2G229 was too low we switched to observing PSZ2G107 but could not focus correctly, finally focus 2251+158 on and did 1 full repetition ( 20251119s157-160 )

18:00 -24:00 Sihan: get good focus at 18:20 then do skydip. The weather is very good and stable (tau <0.15 and <1 jy/beam), and switch to NIKA2pol for project 084-25. Exceptional tuning (9/9/12 bad kids in Ar1/2/3). Pointing, focus and calib_1scan (20251119s188) on 3C454 (2251+158), which has similar elevation with selected target (IRAS23151). Finish one repetition and then go back to 3C454 (2251+158) to do calib_1scan (20251119s209,20251119s219), pointing, focus. Go to IRAS23151 for one repetition, Finish one repetition and then go back to 3C454 (2251+158) to do calib_1scan (20251119s229). Flux calibrations on MWC349 (20251119s231), CRL2668 (20251119s232), NGC7027 (20251119s233). We finish the shift with pointing, focus and two beam maps on Uranus, one with focus optimized for Ar1 (20251119s241) and another for Ar3 (20251119s242). for one repetition.

November 20th, 2025, Thursday

00:00-06:00 Tuan-Anh : Continue beam map 20251119s242 from previous shift. Start at 0:54 LT, pointing, focus, calib_1scan on Uranus. Switch to BFUN (015-17), pointing on 0333-321, 1 repetition for NGC1333 with calib_1scan (20251120s15), 1 repetition for OMC-3N with calib_1scan (20251120s19). Switch to nikas-25: pointing, focus, calib_1scan on Uranus, 1 repetition for OMC-2S with calib_1scan (20251120s35), 1 repetition for NGC1333 with calib_1scan (20251120s39). Beam slightly extended 17"x18.5" @2mm.

05:00-12:00 Fengwei : Point, focus, and calib_1scan (20251120s48) on 0316+413. Then skydip. Then calib_1scans (20251120s52, 20251120s54) on ALFORI and CRL618. Change to NIKA2-TP with the special setup for project D01-25 (tuning good 9/6/12 bad kids for Ar1/2/3). Point, focus on 1226+023. Now move to project D01-25. Point on 1418+596. Start Science Scan, for three repetitions. And move to 1418+596 again, check the beam FHWM which is 16x18 arcsec, still good. Keep two repetitions. Reach two hours and move to Point, Focus on 1226+023 (in Project nikas-25). Re-focus and move back to Project D01-25. Start two repetitions.

11:00-18:00 Benedetta : After changing the setup to normal NIKA2-TP mode (good tuning with 9/5/18 bad kids in Ar1/2/3), we do pointing and focus on K3-50A and start with the observations of project 022-25. Start science scan for three repetitons. After checking the beam FHWM which was good (18.12 * 18.59) and weather stability (very good, +/- 1 Jy/beam), started the second three repetition of science scans. Scan 124 has weather stability issues (tau ~ 0.77).

17:00-23:00 Sihan: get good pointing and focus on 2251+158 and then move to project 066-25. When pointing on the nearby pointing source, sky stability +/- 3-4 Jy/beam. After two repetition2, go to 2251+158 to do pointing, focus, and skydip.Flux calibrations on CRL2668 (20251120s170), NGC7027 (20251120s172), MWC349 (20251120s174). @22:15 switch to NIKApol for project 084-25 (tuning good 8/6/18 bad kids for Ar1/2/3). Pointing, focus and calib_1scan (20251120s192) on 3C454 (2251+158), which has similar elevation with selected target (IRAS23151).

November 21st, 2025, Friday

23:00-05:00 Tuan-Anh : Continue science scan in the previous shift then calib_1scan on 2251+158. Start at 00:10 LT, switch to nikas-25, pointing, focus and calib_1scan on Uranus. Switch to B-FUN, pointing on 0333+321 then perform 1 repetition for NGC1333 with calib_1scan (20251121s3), 1 repetition for NGC2024S with calib_1scan (20251121s8). Switch to nikas-25, pointing, focus and calib_1scan (20251121s16) on Uranus. Switch to B-FUN, pointing on 0458-020 then perform 1 repetition for OMC-2S with calib_1scan (20251121s23), 1 repetition for OMC-3N with calib_1scan (20251121s28). Pointing, focus on Uranus then skydip.

05:00-11:00 Fengwei: Taking over from Tuan-Anh. calib_1scan on ALFORI (20251121s038) and calib_1scan on CRL618 (20251121s041), calib_1scan on 3C286 (20251121s044), and calib_1scan on 3C273 (20251121s047). Change to NIKA2-TP (in the D01-25 setup) and tuning looks good (9/7/12 bad kids in Ar1/2/3). Back on D01-25. Four repetitions on M51. After pointing calibration on 1418+546 and find a bit elongated beam. So, Pointing and re-Focus on 1226+023. Then back to D01-25. Two repetitions again on M51.

11:00-17:00 Benedetta: Performed a skydip on nikas-25 project. Performed pointing and focusing on 1226+023. Very good sky conditions 1 Jy/beam. The focusing has been repeated 4 times on source 1226+023 and every time one of the three arrays was not on focus. So we changed to another source, K3-50A, which is less bright but further to the sun. After 2 focusing repetitions we obtained a good compromise at 1.05 mmm to focus the 3 arrays. Then back to project D01-25. Nearby pointing to 1418+56. Size FWHM too elongated (16.95 x 19.58 arcsec). We focus again on a bright source K3-50A. Nearby pointing to 1418+56, beam dimensions FWHM 16.53 x 18.26, sky stability good < 5 Jy/beam. Three repetitions again on M51. Nearby pointing to 1418+56, beam dimensions FWHM 17.4 x 20.79, little elongated but since the project is almost done avoiding refocus to perform one last science scan because sky stability very good < 2 Jy/beam, tau still less than 0.1. Run the last science scan on M51. Refocusing on nikas25, on MWC349. Bad results for array 2. Refocusing.

17:00-23:00 Sihan: Change to NIKA2-TP (from the D01-25 setup) and tuning looks good (13/6/12 bad kids in Ar1/2/3) for project 066-25. Pointing and focus on 3C454 (2251+158). Finish 2 repetition for project 066-25. Flux calibrations on CRL2668 (20251121s204), NGC7027 (20251121s205), MWC349 (20251121s206). @21:20 switch to NIKApol for project 084-25 (tuning good 15/6/10 bad kids for Ar1/2/3). Pointing, focus and calib_1scan (20251121s215) on 3C454 (2251+158). 1 repetition on IRAS23033.

November 22nd, 2025, Saturday

23:00-05:00 Tuan-Anh : Start B-FUN (015-17) at 23:25, switch to nikas-25: pointing, focus on Uranus then calib_1scan (20251121s237). Switch to 015-17, pointing on 0458-020, 1 repetition for OMC-3N with calib_1scan (20251121s244), 1 repetition for OMC-2S with calib_1scan (20251122s4), Pointing, focus and calib_1scan (20251122s12) on Uranus in nikas-25 project. Switch to 015-17, pointing on 0333+321 then do 1 repetition on NGC1333 with calib_1scan (20251122s19), 1 repetition on NGC2024 with calib_1scan (20251122s24) Pointing, focus and calib_1scan (20251122s32) on Uranus in nikas-25 project. Do skydip (20251122s33).

05:00-11:00 Fengwei: Taking over from Tuan-Anh. In nikas-25, do pointing and focus on W3OH. Start 084-25 at 4:22. Point and calib_1scan on 0316+413 (20251122s44). Move on W3OH for pointing. 1 repetition on G138.2957. Point and calib_1scan on 0316+413 (20251122s55). In nikas-25, calib_1scan on 3C286 (20251122s58) and calib_1scan on 1226+023 (20251122s61). Focus on 1226+023. Then go to project 022-25. Start science on Ceph-5. Three repetitions done. Check the pointing and focus. Still in focus so do another two repetitions.

11:00-17:00 Benedetta: Going to 1226+023 to point and focus again. I go to nearby source 1928+738 after 2 focusing repetitions (final focus @2 mmm 17.67x18.49). Wind speed is increasing , tracking has poorer quality but still in the limits. Performing pointing and moving to science source Ceph_5. Performed three repetitions of science scans. Wind is increasing, less tracking precision (but within 2-3 arcsec). After three science scan we go to nearby target 2254+617 to pointing. Focus is not good on this source 23.52x32.89 but maybe because it's too faint. So we try again on 1928+738 even if it's a little too high in elevation respect to science source. Focus good 18.37x18.73 @2 mm, weather stability very good within 1 Jy/beam. No more strong wind, precision back to 1 arcesc in tracking. Start three science scans repetitions for Ceph_5. Close project 22-025 with 17/30. Going to nika25 and performing pointing and focusing on a bright source K3-50A. Focus on another source which is less extended, 1757-240 for focusing. Problems with focusing ar2 and ar3, after 2 try we found the right focus at 0.55 mm. Start skydip. Start calib_scan on MWC349, CRL2688, NGC7027. Insertion of half wave plate and started tuning for polarimetry.

17:00-23:00 Sihan: Pointing, focus and calib_1scan (20251122s165) on 3C454 (2251+158). One repetition on IRAS23033. After one repetition on IRAS23033, move to 3C454 (2251+158) to do calib_1scan (20251122s175), pointing, focus and calib_1scan (20251122s187). One repetition on IRAS23033, the sky is very stable (peak to peak is < 1-2 jy/beam @ 2mm), tau225 is ~0.4 (close the the limitation). After one repetition on IRAS23151, move to 3C454 (2251+158) to do calib_1scan (20251122s199), pointing, focus and calib_1scan (20251122s206). One repetition on IRAS23151, the sky is very stable (peak to peak is < 1-2 jy/beam @ 2mm), tau225 is ~0.4 (close the the limitation). After one repetition on IRAS23151, move to 3C454 (2251+158) to do pointing and calib_1scan (20251122s199). @ 22:50 do skydip and flux calibrations on MWC349 (20251122s).

November 23rd, 2025, Sunday

23:00-05:00 Tuan-Anh : Tau > 0.4 at start of the shift, so we can't observe for B-FUN (015-17) . Start with project 084-25 at 01:30 LT. Pointing, focus, calib_1scan (20251123s35) on 0316+413. Switch to 084-25, pointing on 0224+671, 1 repetition for G138.2957 with calib_1scan (20251123s45). Switch to nikas-25, pointing, focus, calib_1scan (20251123s53) on 0316+413. Switch to 084-25, pointing on 0224+671, 1 repetition for G138.2957 with calib_1scan (20251123s64).

05:00-11:00 Fengwei: Taking control. Finish the polarization calib_1scan in 20251123s64. In nikas-25, pointing and focus on 1226+023. Not parabolic for arr3. So again focus on 1226+023. EMIR test by IM as below. IM - Note of EMIR/XPOL observations: During the night and the unstable sky conditions, I switched to EMIR/XPOL mode to take some polarization observations on the polarization calibrators that we are using for the NIKA2-Pol project this week. The observations were performed for ~ 3.5hrs in total in two slots (00:00-01:30 and 05:00-07:00 local time) within the 000-23 project and the data were collected with the T14-25 project id (scan ranges 20251122s240-20251123s25 and 20251123s65-20251123s111) and observing scripts using E230 and E090, but optimized for E230 (larger bandwidth VESPA part). The sources which were observed are: Uranus, Neptune, 3C84 (0316+413), 3C454.3 (2251+158), 3C286 (1328+307), 3C273 (1226+023) and 3C279 (1253-055). This data will allow us to (1) construct a fine-tuned IP parameter value set to correct for the EMIR/XPOL IP that we have in this session and [using the unpolarized targets in the sample: Uranus, Neptune and 3C84] (2) get updated 1mm polarization values of the variable sources that can be used for NIKA2-Pol calibration purposes [using the variable targets in the sample: 3C454.3, 3C273 and 3C279] and (3) check our calibration approach against the expected polarization of the stable polarization target in the sample, 3C286. In project 022-25, three repetitions [18/30-20/30] on Ceph5. In 022-25 project, pointing and focus on 1226+023. Not parabolic for arr2. So again focus on 1226+023. And do another two repetitions on Ceph5. During the last repetition, hand over to Bene.

11:00-17:00 Benedetta: Continuing the focus on 1226+023. Good focus after 2 repetitions. Continuing project 022-25, point to nearby target 1928+738. Very good focus on nearby target 17.1 x 17.97. Start 3 repetitions of observations on science target Ceph 5. Repointing on nearby target, 2007+776 since 1928+738 is too high in elevation now. Bad focus, tried both on 2007+776 and 1928+738. Mode switched to polarimetry before refocusing. Pointing 1757-240 bright source, focusing repeated 3 times without good results. Change source further to the sun, 2200+420. Pointing and focusing performed (2 attempts). Starting observing project 039-25. Pointing to 3C286 for calib_1scan. Pointing to nearby source 1741-038 and set pointing. Good focus (17.25x18.18 @2mm), good sky stability within 2 Jy/beam, tau ~ 0.3, low wind so high tracking precision. Start science observations for W43 for ~ 1h (4 repetitions). Pointing 3C286 for performing calib_1scan. Pointing 2251+158 for focusing again. calib_1scan

17:00-23:00 Sihan: got good focus on 2251+158, and then do calib_1scan. Do 1 hour scientific observation for project 039-25. After 1 hour scientific observation for project 039-25, we go back to 2251+158 to do pointing, calib_1scan, and focus.@ 19:15 do skydip and flux calibrations on CRL2688(20251123s248), MWC349 (20251123s250), NGC7027 (20251123s252). @20:20 tau is very variable. Switch to NIKA2 total power, and tuning looks good (13/10/37 bad kids in Ar1/2/3) for project 066-25.

November 24th, 2025, Monday

23:00-05:00 Tuan-Anh : Tau > 0.35, sky stability p2p +/- 3~5 Jy/beam, so we can't observe for B-FUN (015-17). Start with project 066-25, 1 repetition for M31_outer, 1 repetition for M31_inner.

Swich to Nika-2 Pol at 03:20 LT. Pointing, focus and calib_1scan (20251124s44) on Uranus. Switch to 015-17, pointing on 0333+321 then do 1 repetition for NGC1333.

05:00-11:00 Fengwei: Taking over from Tuan. In nikas-25, point, focus, and calib_1scan on 0316+413. In 084-25, start 1 repetition for target G138.2957. Weather is as stable as 1-2 Jy/beam when the repetition starts. tau225 is within 0.25-0.31, which is always good for six scans within one repetition. After that, revisit 0316+413 for a calib_1scan. The elevation of 0316+413 is relatively as low as 17 deg. Point and focus and calib_1scan on 1226+023. Point+calib_1scan on 1253-055. Point+calib_1scan on 3C286. 1 skydip.

11:00-17:00 Benedetta: Science scan repetition for project 022-25 on going. Repetition 25/30 over. Pointing to nearby target 1928+738 to perform the pointing and to check the weather stability. Weather conditions good within 5 Jy/beam, but elongated beam 17.16x21.55, but it is a weak source, so check the focus on brighter one 1226+023. Beam size 17.45x20.67, weather still good within 5 Jy/beam. Out of focus so start focusing procedure. Good focus found at 1.12 mm for all arrays. Go back to nearby target 1928+738 and pointing. Start three repetitions for project 022-25 on Ceph_5. Weather stability very good, within 5 Jy/beam and low wind. Good tau ~ 0.14. Starting project 062-25, pointing to nearby 1757-240 for pointing and refocusing. Sky stability getting worse, within 20 Jy/beam. Focus 19.25x25.28 @2mm (need for refocusing as expected).

17:00-23:00 Sihan: