CHIME/FRB Shriharsh Tendulkar Photo credit: Andre Recnik
Fast Radio Bursts CHIME/FRB Capabilities Current Status Recent Results Synergies 2
WHAT ARE FRBS? Very short (~ms), very bright (~Jansky), radio bursts from ~Gpc away Energies of ~10 38 39 erg Luminosities ~ 10 41 ergs/s (wimpy compared to other transients) Similar to pulsar signals (but not periodic, almost all single) Rate ~10 3 /sky/day at 1 Jy (Lawrence+2017, ++) (See frbcat.org; Petroff+ 2017) ~40 reported since 2007 Animation Credit: NRAO Outreach/T. Jarrett (IPAC/Caltech); B. Saxton, NRAO/AUI/NSF 3
FAST RADIO BURSTS Key questions What are FRBs? Are there multiple populations? How do they link to other transients? Tendulkar+2017 Can we use them as cosmological probes? Probing Structure + Turbulence 4
FAST RADIO BURSTS Origins are unclear plenty of models but few constraints Magnetars, pulsars, BNS mergers, NS-BH mergers... Need localization, multiwavelength follow-up No counterparts, afterglows yet sgrbs, GW, kilonovae, MW bursts possible One FRB localized (Chatterjee+2017, Tendulkar+2017) Tendulkar+2017 Promising probes Baryon distributions (Masui & Siggurdson 2015) Magnetic fields (Akahori+ 2017) MACHO dark matter, PBH binaries (Wang & Wang 2018) Probing Structure + Turbulence 5
FAST RADIO BURSTS Origins are unclear plenty of models but few constraints Magnetars, pulsars, BNS mergers, NS-BH mergers... Need localization, multiwavelength follow-up No counterparts, afterglows yet sgrbs, GW, kilonovae, MW bursts possible Need One a large FRB localized homogenous (Chatterjee+2017, complete Tendulkar+2017) sample of FRBs Separate intrinsic properties and propagation Promising probes Tendulkar+2017 Baryon distributions (Masui & Siggurdson 2015) Magnetic fields (Akahori+ 2017) MACHO dark matter, PBH binaries (Wang & Wang 2018) Probing Structure + Turbulence 6
CHIME Canadian Hydrogen Intensity Mapping Experiment Transit telescope designed to study Baryon Acoustic Oscillations at z=0.8 2.5 Four 20m x 100m North-South cylinders 256 dual-pol feeds on each cylinder 400-800 MHz bandwidth FOV: E-W ~2.5 o 1.3 o, N-S ~120 o ~250 sq deg Parkes: 0.6 sq deg Arecibo: 0.02 sq deg \ CFI funded FRB backend for real-time detection: CHIME/FRB 1024 beams from full 4- cylinder CHIME
CHIME FRB RATES 1 10 FRBs per day at 10- sigma Uncertainty due to spectral distribution etc. Frequency band where no FRBs existed Work by Pragya Chawla (Chawla+2017) 8
FRBS AND CHIME What we want Thousands of events for event rate, flux distribution, angular distribution, DM distribution, scattering vs DM, Find Repeaters Real-time triggers Sensitivity to polzn vs freq, vs time Localization: Absolutely necessary for distinguishing models Can CHIME deliver? Yes Flux, spectra corrected for beam sensitivity Yes Yes à GCN, VO, ATel Digest Yes Arcminutes: Within CHIME (SNR dependent) Arcseconds: Maybe, if optical/x-ray bursts/afterglows exist* OR VLBI 9
256 feeds CHIME Analog signal chain Digitizers + FPGAs F-Engine E & W F-Engine Receiver Huts ~ 13 Tbps GPU correlator X-Engine X-Engine N & S GPU Huts 1024 freq channels n 2 visibilities 130 Gbps 30 sec 16k freq channels CHIME Cosmology 1024 stationary CHIME-FRB CHIME-Pulsar intensity beams 1-ms sampling 1024 freq channels 10 tracking voltage beams 2.5-us sampling 10
CHIME/FRB PIPELINE X-Engine Housing CHIME/FRB Housing L0 L1 L2 L3 L4 Single-Beam Analysis Multi-Beam Analysis Buffer FFT beamforming 1024 intensity beams Upchannelization 256 nodes 128 nodes 128 streams L0 node L0 node L0 node 64 freq. chan. x 8 beams RFI rejection Dedispersion & Detection Sifting/grouping L1 Node L1 Node L1 Node Buffer Intensity callback Baseband callback Grouping RFI rejection Localization L2/L3 Node Flux estimation Source identification Extragalactic check Action decision Action implementation Databases Header data Intensity data Baseband data Offline analysis Web interface+alerts Archiver + DB Pulsar tracking beam Alert community Key challenge: Real time (dispersion sweep + 2-3 seconds) M. Boyce, P. Boyle, S. Brar, D. Cubranovic, E. Fonseca, U. Giri, A. Josephy, V. Kaspi, K. Masui, A. Naidu, C. Ng, C. Patel, Z.Pleunis, M. Rafaiei, P. Scholz, K. Smith, SPT Process 13 Tbps data Clean, real time RFI removal 11
Aeroplanes By Charles Moatti FRB! Pulsar Viewer made by Alex Josephy 12
FIRST FRB FRB 180725A First FRB detection lower than 700 MHz Others going all the way to 400 MHz 13
CHIME FUTURE CHIME FRBS DM = 849.19 pc cm 3 (DM gal = 70 pc cm 3 ) DM = 1005.49 pc cm 3 (DM gal = 233 pc cm 3 ) DM = 316.93 pc cm 3 (DM gal = 80 pc cm 3 ) PRELIMINARY PRELIMINARY Time span = 256 ms Time span = 256 ms CHIME/FRB Collaboration 14
CHIME FUTURE Currently pre -commissioning and calibrating Good up time in running 1000 beams on the sky, 24/7 CHIME Commissioning à Full operation Detect 360 3600 FRBs per year Studying outriggers for CHIME/FRB Can we get milliarcsecond localization for every FRB? 15
SYNERGIES Associating FRBs to hosts Arcsecond localization is challenging Correlating FRB positions to galaxies, radio sources, other source types Photo-z and spectroscopic surveys SDSS, WFIRST, EUCLID, LSST Find prompt counterparts In microwave bands with CMB experiments Optical rapid imaging, simul. observations X-ray simultaneous observations Eftekhari+2017 Afterglows Search for faint optical, X-ray, GW transients LSST, VLASS SPT Collaboration 16
Synergies Positions VLA, CHIME/OT, SKA Simulobserving With other FRB searches CHIME Population FRBs Optical/X-ray facilities 1) Burst/Afterglow 2) Host galaxies Theoretical Progress! X-ray/Gamma-ray Facilities LIGO Multi-λ Follow up Counterparts / Afterglows 17
Stay tuned 18