MeerKAT Status AUGUST 2017 Francois Kapp (on behalf the entire SKA - - PowerPoint PPT Presentation

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

• ffset 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

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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)

www.ska.ac.za

• 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.