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Status of MKSP LOFAR Observations Andreas Horneffer Contents Where we are Open Issues Old observations Cycle-0 observations My list of Milestones Cycle-0 and Cycle-1 Observations 2 M51 Early Image 3C295 field M51 closeup M101 M51 with 3C295 as calibrator Observed to test calibration interpolation and study M51 D. Mulcahy 3 M51 Better Image After ca. 9 months of work D. Mulcahy 4 NGC891 1 subband, basic calibration selfcal-bias source held for a real transient 5 Fan Region FD = -5 rad/m/m FD = -2 rad/m/m M. Haverkorn, M. Iacobelli 6 Double Double B1835+620 M. Orru 7 Prediction of Ionospheric RM from GPS data C. Sobey and C. Sotomayor Comparison of Ionospheric RM prediction (red) and pulsar data (blue). Ionospheric RM prediction can be included in BBS 9 IC342 C. van Eck Cycle-0 regular observation data 1 Subband, basic calibration 10 Open Issues List of Milestones: Normal Imaging 1. Long integrations of polarization 2. RM Cubes with absolute FD 3. 4. 5. Multi-hour observations Multi-Epoch observations High Resolution in FD Low instrumental Polarization High angular resolution 11 Milestone 0: Normal Imaging Need to calibrate data: Selfcal needs good model of the sky to work Station clocks Ionospheric delay Station gains (incl. dipole gains) Have a good sky model from e.g. MSSS Transfer solutions from a second beam on a calibrator. Be careful when using e.g. gsm.py skymodel! Demixing, sagecal, BBS must not corrupt polarization information. Still several Features missing in the software 12 5ns Problem Solved LOFAR had a major hardware issue last year “5 ns” issue This has been solved with new hardware 13 Milestone 1: Long Integrations Needs Conversion between visibilities and Stokes parameters done correctly correct beam model -> test it with pulsar and all sky data Needs the ability to correct for changes in the ionospheric RM calibrate on pulsars or with GPS based corrections -> GPS based corrections alone are not good enough. 14 Ionospheric RM Correction 15 Ionospheric RM Correction 16 Milestone 2: RM Cubes with absolute FD Needed for multi-epoch observations Needs at least one calibrator with known absolute RM Get it from studies of measured RM and e.g. ionospheric RM from GPS Connect the position angle of a source (a blazar?) to higher frequencies. “Assign” a RM to a calibrator and use it as reference Propagate absolute RM to all calibrators 18 Milestone 3: High Resolution in FD Needs wide frequency coverage -> 8-bite mode works! Multi-epoch observations for HBA low and high? Use the low-band? Probably not… 19 Milestone 4: Low Instrumental Polarization Good understanding of the instrument For the time being: flag out parts at RM ≈ 0 20 Milestone 5: High Angular Resolution Needs us able to deal with long baselines. Made a start at the long-baseline BW Rely on the long baseline working group for the time being. 21 LOFAR Cycle 0 Regular Cycle 0 observations started December 2012 Originally planned till end of August 2013 Extended till 14. November 2013 The nearby galaxies proposal got granted: (To implement and test the new correlator.) 112 hours observing time 213 hours computing time We asked for more time due to the extension 22 LC0 Scheduling March - August 23 MKSP Clycle-0: Nearby Galaxies Target M31 Band Observer Requested time Observed Date HBA (110-190) LBA (30-88) HBA (110-190) LBA (30-88) HBA (110-190) HBA (110-190) Giessuebel Giessuebel Paladino Paladino Mulcahy Adebahr LBA (30-88) Adebahr NGC3079 HBA (110-190) LBA (30-88) HBA (110-190) Mulcahy Mulcahy Sotomayor NGC4631 NGC6946 IC342 HBA (110-190) HBA (110-190) HBA (110-190) Sotomayor Jurusik Mulcahy / v.Eck, Pietka LBA (30-88) Mulcahy or Adebahr M101 NGC3627/3628 HBA (110-190) HBA (110-190) Heald / Toribio Drzazga / Paladino IC10 HBA (110-190) LBA (30-88) HBA (110-190) HBA (110-190) Heesen Heesen Nikiel-Wrochzynski Nikiel-Wroczynski M33 M51 M81/M82 NGC891 Holmberg 124 Stephans Quintet UTC Time LST Range 8h New Time 8h New Time 8h New Time 8h New Time 8h 5h 5h 5h 5h Cycle-1 Cycle-1 0h 26. Sep. 2013 27. Sep. 2013 9. Oct. 2013 10. Oct. 2013 22. Apr. 2013 6. Mar. 2013 30. Mar. 2013 21. Feb. 2013 31. Mar. 2013 20:00 – 04:00 20:00 – 04:00 20:00 – 04:00 20:00 – 04:00 20:00 – 04:00 21:26 – 02:30 19:00 – 00:20 21:05 – 02:10 19:00 – 00:00 10:30 – 18:30 08:52 – 14:00 08:00 – 13:21 07:40 – 12:46 08:04 – 13:05 ---- ---- ---- 8h 8h 5h 5h 5h 5h 8h 4h 4h 8h 8h --8h 9. Apr. 2013 15. Jul. 2013 2. Feb. 2013 13. Mar. 2013 30. Jan. 2013 21. Feb. 2013 9. May. 2013 19. Mar. 2013 2. Apr. 2013 25. Aug. 2013 26. Aug. 2013 ---19. Aug. 2013 18:00 – 02:00 20:00 – 04:00 15:50 – 20:50 22:20 – 04:00 16:00 – 21:00 16:00 – 21:00 19:00 – 03:00 22:00 – 02:30 21:20 – 01:30 19:00 – 03:00 19:00 – 03:00 ---20:00 – 04:00 07:40 – 15:41 16:02 – 00:04 01:09 – 06:10 10:14 – 15:55 01:07 – 06:08 02:34 – 07:35 10:38 – 18:39 10:17 – 14:48 10:30 – 14:40 17:48 – 01:49 17:48 – 01:49 ---18:20 – 02:22 25 Cycle-0 Processing/Analysis Quite a bit of the MKSP Cycle-0 data is currently only archived, but not looked at. The problems are manpower and processing capabilities Processing (data storage) at CEP-1 only guaranteed for 4 weeks. Processing at other places (e.g. Bonn Juelich) possible but cumbersome. For new observations: include manpower and processing in your plans from the beginning. 26 LOFAR Cycle 1 Next observing cycle for LOFAR Planned to run for 6 months Call for Proposals planned for end of May Deadline: end of August Start of observations: 15. November 27 Summary LOFAR is reliably taking science data Data quality has improved Still many features missing in the software. Calibration quality is continuously improving Still a lot of manual work but getting better Quick image with basic calibration can be made by the RO Good (state of the art) images take about 9-12 months dedicated work There is new data available Polarization calibration needs still more work, but I’m still confident that we’ll manage it with time. 28 Questions? 29 Discussion: What new observations are needed? Science goals? Who is going to do the work? Where is the processing going to be done? Does she/he have the time and experience? Even just moving around the data takes time! LOFAR in three lines: Total power is possible now. Low noise and/or high resolution is a lot of work. Polarization is even more work. 30