Radio Transients with Apertif Joeri van Leeuwen

Radio Transients with Apertif Joeri van Leeuwen

[ movie at alert.eu.org ]

Apertif Phased Array Feeds 1.4 GHz, 300 MHz bandwidth, T sys = 70K

Apertif WSRT: Increased field of view 8.7 sq. deg. instantaneously

Apertif Status and timeline Dishes: all 12 retrofitted

Apertif Status and timeline Frontend PAFs: all in place

Apertif Status and timeline Frontend Cabling and Electronics: all in place

Apertif Status and timeline Correlator/Beamformer Electronics: all in place

Apertif Status and timeline Correlator/Beamformer Firmware & Software: in place, being commissioned now, 2016Q3 (Roy Smits, Emily Petroff, Yogesh Maan, Klim Mikhailov, Samayra Straal, Leon Oostrum,..)

Apertif Status and timeline Survey team: formed, buy-in continues to be possible, for data access before public release https://www.astron.nl/radio-observatory/apertif-surveys 10

Apertif Status and timeline Survey definition (5yr) : agreed and published, https://www.astron.nl/radio-observatory/apertif-surveys Imagining surveys commence 1 Jan 2017, time-domain (dedic. + comm.) starts 1 March 2017 Imaging (shallow + medium-deep) Time-domain dedicated (ALERT)

Science Overview What is the fundamental physics of space-time and matter? Where does our understanding of general relativity break down? How is matter accreted and expelled in strong gravity? How do black holes influence galaxy formation? Discover and characterize cosmological radio bursts, supernovae, neutron stars, and black holes.

Science Supernovae and Gamma-Ray Bursts Paragi et al. (2010)

Science Neutron Stars After Demorest et al. (2010)

Science Cosmological radio bursts Fast Radio Bursts (FRBs) at cosmological distances 2007 Parkes Lorimer burst 2013 Arecibo burst Spitler et al. (2014, 2016)

Science Cosmological radio bursts The origin of the bursts remains unexplained. Coalescing compact objects? X-ray afterglows Connected to the unexplained slow radio transients? Radio afterglows Supernova related? Optical, host galaxies Naked explosions? Consistent absence of galaxies Detect, localize, characterize

The ALERT survey Apertif: 8.7 deg 2 field, 20 frames/ms Westerbork Apertif

The ALERT survey LOFAR: resolution and sensitivity, at low frequency see Coenen, van Leeuwen et al. 2014

The problem and the opportunity

The solution: a real-time hybrid FPGA-GPU transient machine 2.1 Tbps > 150 Gbps 25 TMAC/s 150 Gbps -> 3.0 Tbps -> 0.2 Gbps 500 TFLOPS

The solution: a real-time hybrid FPGA-GPU transient machine 16 Uniboard (128 Altera Stratix IV) [ 450 TABs, dedicated ] 5 Uniboard 2 (20 Altera Arria10) [ 250 TABs, 24/7 ] 40 Servers 640 CPU Cores 160 GPUs (NVIDIA/AMD) 1 PFLOP (Top 250) 1 PB disk 10 TB RAM 50 Gbps to the world 6 Racks 50 kw (Air+Water cooled)

The solution: a real-time hybrid FPGA-GPU transient machine 16 Uniboard (128 Altera Stratix IV) 5 Uniboard 2 (20 Altera Arria10) 40 Servers 640 CPU Cores 160 GPUs (NVIDIA/AMD) 1 PFLOP (Top 250) 1 PB disk 10 TB RAM 50 Gbps to the world 6 Racks 50 kw (Air+Water cooled)

Fast transients: the ALERT survey after Coenen, van Leeuwen et al. 2014

Fast transients: The ALERT survey compared

Fast transients: The ALERT survey follow-up Radio, x-ray, gravitational-wave & optical follow-up Interpretation & modelling Host and progenitor associations, expected rates Electron density and distribution along lines of sight Coherent & afterglow emission, acceleration, densities

Slow transients: The Apertif Medium Deep Seven 12-hr repeats at 15 μjy/beam each, over 450 sq. deg. When emphasizing 3-month cadence, the peak timescale at 1.4 GHz for the afterglows for GRBs and TDEs: after Carbone et al. 2016

Conclusions Apertif on WSRT will offer a combination that is unique in the world, of wide-field detection and high-precision radio characterization. Through blind and triggered searches for fast and slower transient radio emission we intend to understand how dense matter behaves under extreme gravity.