MeerKAT Status AUGUST 2017 Francois Kapp (on behalf the ... · AUGUST 2017 . Francois Kapp (on...
Transcript of MeerKAT Status AUGUST 2017 Francois Kapp (on behalf the ... · AUGUST 2017 . Francois Kapp (on...
AUGUST 2017
Francois Kapp (on behalf the entire SKA South Africa team)
MeerKAT Status
www.ska.ac.za
www.ska.ac.za
MeerKAT
MeerKAT construction - Dishes 64 x 13.5m highly efficient offset Gregorian dishes spread over 8 km (~75% within ~1km diameter)
MeerKAT construction – Feeds and Digitisers
MeerKAT construction – Time and Frequency Reference
MeerKAT construction – Correlator Beamformer
MeerKAT construction – Array Releases
• Array releases: planned engineering milestones to enable early integration, test, verification and observations to support this
• AR1 – June 2016 • AR1.5 – March 2017 • AR2 – late 2017 • AR3 – Q2 2018
• Followed by commissioning and
then science use
MeerKAT construction
Receivers: L-band receivers (0.9–1.67 GHz) UHF (0.58–1.0 GHz) S-band (1.75–3.5 GHz) X-band (8 – 14.5 GHz) planning stage
Extremely good L-band performance - Tsys
Note: the resonant peak at 1420MHz is a measurement artifact that could not be calibrated out with sufficient accuracy
Extremely good L-band performance – Ae/Tsys
www.ska.ac.za
KAT-7 (engineering testbed) image in 2012
www.ska.ac.za
4-dish MeerKAT in May 2016 (commissioning)
www.ska.ac.za
16-dish MeerKAT in June 2016 (Array Release 1)
1% of First Light image
www.ska.ac.za
www.ska.ac.za
www.ska.ac.za
www.ska.ac.za
www.ska.ac.za
Technical challenges
MeerKAT Data Rates
MeerKAT SDP Hardware Landscape
1.6 PFLOPs (GPU)
23 PBytes (Disk - CEPH)
40 PBytes (Tape)
www.ska.ac.za
● 32 dishes available (square surrounding core is 1.2 km on the side)
● SKA SA commissioning team making a variety of observations to test telescope
● Closer commissioning interaction with LSP teams starting in May 2017
Array configuration in April 2017
www.ska.ac.za
Commissioning in April 2017, up to 32 antennas
www.ska.ac.za
● 4K channels
● 16 antennas dual-polarisation
● 12 hour track observed on 2017-04-04
● Imaged with 2 x phase + 1 x amplitude self-calibration on 16 s timescale
● With Briggs -0.5 weighting image has 9 μJy/beam (vs 10 μJy/beam in June 2016 image)
● Thermal is ~8.5 μJy/beam
● 1800 sources in central degree of field (vs 1400 in first light image)
“DEEP2 “
Early 8 km-baseline observations
Array layout
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(Tom Mauch)
FRII type galaxy – offset vs centred
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● 32K channels (140 imaged)
● 16 core antennas, dual polarisation
● 9 hour track, 2017-04-05
● Mosaic: 7 pointings
● ~50 minutes per pointing
● Min baseline (projected): 16 m
● Max baseline: 711 m
● Beam 90x70 arcsec
● Measured rms 2.8 mJy (emission-free chan) vs 2.3 theoretical
(Spiral galaxy at 5 Mpc discovered in Cape Town in 1752 by Louis de La Caille)
HI emission in M83
www.ska.ac.za
M83 (Sean Passmoor)
www.ska.ac.za
● 8 channel binning
● No self-cal or primary beam corrections
● Imaged using wsclean:
● Multifrequency synthesis (7 channels)
● Multiscale (largest scale ~70 arcmin)
● Briggs robust 0
● Beamsize 58x64 arcsec
G330.89-0.36 star forming region (continuum, 32k mode)
● ATCA SGPS: 5 configs, 30 m – 3 km baselines
● Smoothed resolution 100 arcsec, sensitivity up to ~30 arcmin
ATCA (Sharmila Goedhart)
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● Hint of extended source in SUMSS
● 7-point MeerKAT mosaic in 4K mode
● Radio source (blue) angular size = 0.8 deg; elliptical galaxy (red/IR) at z = 0.02; linear size = 1.2 Mpc: GRG
(Nadeem Oozeer)
A newly identified Giant Radio Galaxy
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An extra (cool) detection in the new DEEP2 pointing (Spiral galaxy in continuum [and optical] at 70 Mpc)
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● AR2 within weeks
● AR3 within months (Q2 2018)
● Many hours of Commissioning
● Formal operations
● Eventually: Integration with SKA1…
MeerKAT: What is next?
Thanks
SKA South Africa, a Business Unit of the National Research Foundation, is supervising South Africa’s involvement in the SKA on behalf of the Department of Science & Technology.