VLA archive file 22B-193.sb43003623.eb43145710.59933.73626988426

[eacmills]

SB 43003623
JACKS region 11

• Observations completed
• VLA CASA Calibration pipeline run by observatory
• Weblog downloaded and unpacked
• Raw data downloaded (specify where)
  • local machine
  • Globus
• Pipeline calibration assessment
• Calibrated MS generated
  • Uploaded to Globus
• Imaging: Continuum
• Imaging: Lines
  • NH3 (1,1)
  • NH3 (2,2)
  • NH3 (3,3)
  • NH3 (4,4)
  • NH3 (5,5)
  • H2O
  • H64
  • H66
  • NH3 (2,1)
  • NH3 (3,2)
  • NH3 (4,3)
  • NH3 (5,4)
  • NH3 (6,5)

Product Links

[eacmills]

---

Log Name: 2022-12-20_1740_22B-193
Project: 22B-193
SBID(s): 43003623
EBID(s): 43145710
Observing Date: 20-Dec-2022
Observation Type: Science
Bands Used: X K
No. Subarrays: 1
Observer(PI): Prof Elisabeth Mills
Source File(s): 22B-193_sb43003623_1_1
Operator(s): Deena Mickelson
Array Configuration: C
Decommissioned Antenna: 12

Adobe PDF version of this log is located at:
http://www.vla.nrao.edu/operators/logs/

***** WEATHER INFORMATION *****

Time(UTC) Dew Pt Temp Wind Bar Press API RMS Phase(degs)
20Dec 17:40:55 -8.0 1.1 NE at 0.8 m/s 794.5 4.0
20Dec 18:00:12 -8.7 2.2 NE at 1.1 m/s 794.3 6.3
20Dec 19:31:12 -14.5 5.5 SE at 1.9 m/s 792.8 6.1
20Dec 20:00:17 -15.4 6.5 SE at 0.4 m/s 792.3 3.1
20Dec 20:54:26 -14.7 7.1 E at 0.9 m/s 791.7 3.2

*** Operator comments for the above weather entries ***

20Dec 17:40:55 Sky cover 80%. Stratiform clouds.
20Dec 18:00:12 Sky cover 80%. Stratiform clouds.
20Dec 19:31:12 Sky cover 90%. Mixed clouds.
20Dec 20:00:17 Sky overcast. Mixed clouds.
20Dec 20:54:26 Sky overcast. Cumuliform clouds.

***** COMMENTS AND OUTAGES *****

Outage information format:
Start Time, End Time, Category, Form#, # Antennas, Down Time(minutes)
Antenna ID(s) and Data Effect
Description

Number of Antennas Used: 27

20Dec 17:40:13
Starting project 22B-193.

20Dec 17:40:13
The band(s) used is(are): X K.

20Dec 17:40:38
On source 3C286 with all available antennas.

20Dec 17:40:13
To access your data from the NRAO archive visit:
https://science.nrao.edu/facilities/vla/archive
All VLA science data are processed through the VLA calibration pipeline. Details
are at: https://science.nrao.edu/facilities/vla/data-processing/pipeline
For further questions please use the NRAO Helpdesk at:
https://science.nrao.edu/observing/helpdesk
Adobe PDF version of this log is located at:
http://www.vla.nrao.edu/operators/logs/

20Dec 17:40:13
Note: To support our ongoing RFI monitoring efforts, any feedback from your
program on RFI can be sent to: [email protected]
The key information to provide is:

• Observation/project code
• Frequency and Time of the observations
• The characteristics of the RFI signal, in particular if it is continuous or
  intermittent?
• If possible, a spectrum of the RFI should be included in the e-mail.
  Thanks very much for your support; this information will be continuously
  updated on the EVLA science pages at:
  https://science.nrao.edu/facilities/vla/docs/manuals/obsguide/modes/rfi/

20Dec 17:40:13 20Dec 21:09:44 LO-IF WO-15503 0.23 48.2
Antenna(s) 14 (Data: Lost):
Antenna 14 IFs C0, C1 and C2 weak/dead due to T304-c trouble.

20Dec 17:41:16 20Dec 17:44:17 LO-IF WO-15894 1.00 3.0
Antenna(s) 26 (Data: Lost):
Antenna 26 L302-1 lost M-lock.

20Dec 17:40:13 20Dec 21:09:44 LO-IF WO-15816 0.50 104.8
Antenna(s) 8 (Data: Lost):
Antenna 8 S1-1 band switch fails in K-band causing dead IFs A and B.

20Dec 17:55:16 20Dec 17:59:12 LO-IF WO-15894 1.00 3.9
Antenna(s) 26 (Data: Lost):
Antenna 26 L302-1 lost M-lock.

20Dec 18:08:24 20Dec 18:43:17 HVAC WO-15860 1.00 34.9
Antenna(s) 15 (Data: Lost):
Antenna 15 parked so Antenna Mechanics can fix the dry air compressor.

20Dec 18:06:11 20Dec 18:10:27 LO-IF WO-15894 1.00 4.3
Antenna(s) 26 (Data: Lost):
Antenna 26 L302-1 lost M-lock.

20Dec 19:39:54 20Dec 19:57:31 LO-IF Other 1.00 17.6
Antenna(s) 1 (Data: Lost):
Antenna 1 L302-1 lost M-lock.

20Dec 19:39:56 20Dec 19:57:09 LO-IF WO-15894 1.00 17.2
Antenna(s) 26 (Data: Lost):
Antenna 26 L302-1 lost M-lock.

20Dec 20:26:51 20Dec 20:27:27 LO-IF WO-15894 1.00 0.6
Antenna(s) 26 (Data: Lost):
Antenna 26 L302-1 lost M-lock.

Project End Time Total Time % Down Time Total Down Time
(minutes x 27 ants) (minutes)

20-Dec-2022 21:09:44 5657.0 4.1% 234.5

[eacmills]

Issues noted but not flagged by staff during pipeline run:

• ea14 - hardware issues on left polzn A0C0
• ea08,ea26 - high scattered delays on A0C0
• ea09 - hardware issue on left polzn B0D0
• ea10 - pointing issues
• ea18 - hardware issues on right polzn A0C0
• ea28 - hardware issue on right polzn
• ea05 - phase split by baseband
• high weights in ea14, spw=2~15, scan=5,17, probably due to hardware
  failure resulting in very low amplitudes for a duration

[xinglunju]

Pipeline calibration

---

Flagging summary

• Amplitude and bandpass calibration 3C286: 100% of ea08 and half of the spws of ea26 have been flagged. As a result, the corresponding phase calibrator and science target data of these two antennas have to be flagged too. Need to double check when re-running pipeline or running manual calibration.
  
• Phase calibrator J1744: In general the flagging fraction per antenna is <50%. Some antennas have higher flagging fractions (>50%), e.g., ea01, ea14, ea15, ea22, ea27. This likely leads to additional flagging for the science targets, because the science targets have to be bracketed by observations of phase calibrators, and if any phase calibration data were flagged, then the science target data in between have to be flagged as well.
  
  An example, one of science targets, CMZ_11a: in addition to the flagging toward ea08/ea26 due to Amp/BP cal flagging, we see additional flagging toward ea15 and ea22.
  
• In ordrer to find out why these data were flagged, we can dig into the cata logs (links at the bottom of each stage). TBD...

By Task notes

• ‘8. RFI Flagging’ (same in 10. RFI Flagging, 15. RFI Flagging): why the amplitude gets higher after RFI flagging? The vertical scales of the two plots are identical:
  
  
• ‘12. Flux density bootstrapping and spectral index fitting’: fitting result of the flux and spectral index of the phase calibrator J1744. Seems about right...
  
• ‘13. Final calibration tables’: a few plots showing the calibration solutions.
  • Final Amp Time Cal plots, for each antenna. ea14 shows amplitude jumps:
    
  • Final Amp Freq Cal plots, for each antenna. Again, ea14 shows large scatter. Bad BP calibration? But the Bp Amp/Phase Solution plots look ok.
    
  • Final Phase Gain Cal plots, for each antenna. Note the phase wrapping, which is fine:
    
• '17. Plot Summary': an antenna shows strange behavior in phase vs. frequency (the yellow dots): bad BP solutions for this antenna (likely ea14 as we spotted...)?
  
• '19. Tclean/MakeImages': the calibrator images look good.
  • Peak intensities ('pbcor image max') are consistent with calibrator fluxes (from stages 4 & 12), suggesting that the calibrators are point sources.
  • Image beam size of the phase calibrator J1744: 1.88 x 0.737 arcsec. The beam size of the science targets will be similar.

[xinglunju]

Other notes

---

• In ‘15. RFI Flagging’: If a file with continuum regions is specified, then the task will only flag those spw and frequency ranges per the pipeline spectral line heuristics. – is this what we need for skipping RFI flagging in the pipeline?
• How to plot phase vs. time in step 17?

[xinglunju]

A quick-look continuum image, made by the imaging script.

TBD:

• Flagging possible RFI, line contaminiation, etc.
• Self calibration, using either the continuum itself or H2O masers
• Try wide-field imaging?

[xinglunju]

Comparison of JACKS (left) vs MeerKAT 1.28 GHz continuum (right)