Kaspi_RadioTransients_LRP2020 2 Liu_21cm_cosmology 17 Benneke_Exoplanets 63 BolducDuval_EPO 77 Rowe_Comprehensive_univ_LRP-Townhall-UdeM 89 Spekkens_EDI_Montreal1Nov 101 Radio Transients Vicky Kaspi McGill U. For J. Ruan (McGill), G. Sivakoff (U. Alberta), P. Boyle (McGill), J. Brown (U. Calgary), M. Dobbs (McGill), M. Drout (U. Toronto), E. Fonseca (McGill), D. Haggard (McGIll), K. Masui (MIT), A. Naidu (McGill), C. Ng (U. Toronto), U. Pen (U. Toronto), P. Scholz (U. Toronto), J. Sievers (McGill), K. Smith (Perimeter), I. Stairs (UBC), K. Vanderlinde (U. Toronto) Kaspi_RadioTransients_LRP2020 2 Introduction • Revolution driven by primarily by computing • Radio transients: • Fast Radio Bursts • Relatively new (since 2007) • Slow transients -- (GRBs, Novae/SNe, Tidal Disruption Events, X-ray Binaries) • Slow transients -- Multi-messenger (DNS, NS/BH) • aLIGO/Virgo GW revolution • Open questions described in WP and summarized here represent science recommendations for attention by WP authorship (but no TDE champion) • Not considering pulsars, AGN, blazars here Kaspi_RadioTransients_LRP2020 3 Other relevant WPs • E018 Lead: J. Di Francesco “The Next Generation Very Large Array” • E023 Lead: R. Hlozek “Science with the Large Synoptic Survey Telescope” • E029 Lead: K. Vanderlinde “The Canadian Hydrogen Observatory and Radio-transient Detector” • E035 Lead: J. Ruan “A Vision for Canadian Leadership in Multi-Messenger Astrophysics in the Next Decade” • E042 Lead: K. Spekkens “Canada and the SKA from 2020-2030” • E075 Lead. M. Rahman “Probing Diverse Phenomena through Data Driven Astronomy” Kaspi_RadioTransients_LRP2020 4 Fast Radio Bursts: Introduction • Few-ms bursts of radio waves • ~1000/sky/day • Dispersion Measure (DM) indicates cosmological distances • Unknown origin • Few dozen published thus far • Several localizations thus far, host galaxies confirm cosmological • Some sources repeat CHIME/FRB Collaboration, ApJL, 2019. Kaspi_RadioTransients_LRP2020 5 CHIME/FRB Results Summarized • First light July 2018 8 New repeaters, ApJL 2019 • Commissioning phase ending soon • Have detected 100s of events • 5 papers: • Overview, ApJ 2018 • 1st 13 events, Nature 2019 • 2nd repeater, Nature 2019 • 1st repeater detected, ApJL 2019 • 8 new repeaters, ApJL 2019 First 13 events; 2nd repeater • Many papers in prep. Nature, 2019 Kaspi_RadioTransients_LRP2020 6 FRB Open Questions 1: What is their Nature? • Are FRBs Young or Old? Typically models suggest one or other (e.g. magnetar vs DNS); need localizations! • Are FRBs a Single Class? Are FRBs homogeneous pop. or are there multiple types? Hint: some repeat…need lots of detections, localizations • Could all FRBs be Repeaters? Could all be repeaters? Some analyses suggest yes…CHIME/FRB helpful • What are FRB Environments? What are their environments like? Counterparts? Need localizations, multi- wavelength follow-up • What is the Nature and Emission Mechanism of FRBs? What are FRBs and how do they produce such high L’s? Kaspi_RadioTransients_LRP2020 7 FRB Open Questions 2: Cosmic Probes? • Can FRBs solve the “Missing” Baryon Problem? FRB DMs sensitive to warm/hot IGM and galaxy e- haloes; need 104 FRBs or more; more enabled with localizations/redshifts. • Can FRBs Constrain Cosmology/Fundamental Physics? Variety of applications beyond MBP: CMB optical depth, tests of EP, kSZ, photon mass limit, …; need large numbers, high z’s • Can FRBs Constrain Cosmic Magnetism? Precision RMs for large, localized sample could detect B-field order on large scales, expected for primordial fields; need large numbers • Can we Detect FRB Gravitational Lensing? Detection of lensing could constrain dark matter in 20-100Msun black 4 5 holes; Ho measurements maybe too. Need 10 -10 events. Kaspi_RadioTransients_LRP2020 8 Slow Transients: Open Questions • What are the properties of relativistic jets and how do they evolve? Jet morphology poorly known; sensitive radio and multi-wavelength imaging & timing obs will make great progress; ngVLA, SKA, CHORD • Are relativistic jets launched due to the spin of the accretor or the accretion disk? High-res imaging, monitoring of many accreing NS, TDEs needed in concert with multi-wavelength obs; SKA, ngVLA, CHORD • What are the explosion mechanisms and progenitor systems of explosive transients? Monitoring of radio emission from explosive transient probes env. of progenitor: need ngVLA, SKA-1 Mid, CHORD • What is the nature of the transient radio sky? Systematic wide-area radio survey unprecedented; e.g. VLASS, AVSTS could reveal thousands of new sources; will require deeper follow-up with SKA-1 Mid, ngVLA Kaspi_RadioTransients_LRP2020 9 Slow Transients & MMA: Open Questions • DNSs always produce GRB jets? Some jets may be “choked” by ejecta; need to observe many DNS mergers with high sensitivity, resolution • Structure of GRB jets? Top hat vs structured: need to monitor many in radio post-merger with high sensitivity • Kilonova ejecta make synchrotron afterglows? Fainter, peaks later than jet afterglow but can constrain eject properties, nucleosynthetic yield; need high sensitivity monitoring • Measure Ho ? GWs give d, galaxy-ID gives z. But d-i degeneracy; can be broken via radio obs & modelling of synchrotron afterglow to get jet angle Kaspi_RadioTransients_LRP2020 10 CHORD Upcoming/Envisioned Instruments I • CHIME/FRB Outriggers • Build 2+ distant stations, buffer baseband & dump at CHIME/FRB trigger (Phase 1 of CHORD) • Initial design funded by Moore Foundation • CHORD (WP by Vanderlinde et al. E029) • Factor of several > rate rel. to CHIME: ~104/yr achievable • Unique broadband detection for emission mechanism, propagation • Localization of all events to tens of mas Kaspi_RadioTransients_LRP2020 11 Upcoming/Envisioned Instruments II • ngVLA (WP by di Francesco et al. WP E018) • SKA (WP by Spekkens et al. WP E042) ngVLA • For FRBs: • useful for repeater studies, SKA-1 Mid monitoring/study of localized FRBs • SKA1-Mid likely best option for FRB discovery, offering ~CHIME rate and localization (Macquart et al. 2015) • For Slow Transients: very useful for high-sensitivity monitoring of light curves, esp. in concert with other bands e.g. X-rays. Also high-res imaging very useful. Kaspi_RadioTransients_LRP2020 12 Instrument Comparison Matrix CHIME/FRB CHORD ngVLA SKA Outriggers FRB Nature A A B B- FRB as Probes A A C B- Slow Transients C B A A Slow Transients - MMA C B A A Kaspi_RadioTransients_LRP2020 13 Risks Logistical/Political Risks Science Risks • • FRBs: not realizing their potential as CHIME/FRB Outriggers: CHIME cosmic probes by not having a large requires continued operations sample with z’s. • Mitigated by CHIME/Outriggers and funding post-2022; no obvious CHORD; SKA1-Mid could help too source but time delay a factor! • FRBs: could we learn something that • FRB localization: need time on would change observational strategy optical telescopes to identify • Regardless, want high stats, localizations host galaxies, measure z’s. • Multi-messenger astrophysics: observable DNS and NS/BH mergers • Wide-field optical surveys (LSST, rare PanSTARRS) will mitigate this Kaspi_RadioTransients_LRP2020 14 Synergies • FRB localization synergy with optical observers, wide-field • E.g. LSST • FRB cosmological probes synergy with cosmology and galaxy evolution communities • Slow transients naturally multi-wavelength; synergy with other observational communities; science synergy with compact objects community • MMA synergy with multi-wavelength and GW communities; compact objects community • General synergies with Big Data, HPC community Kaspi_RadioTransients_LRP2020 15 Multi-wavelength timing probes jet properties and launching Black Hole X-ray Binary Cyg X-1 (VLA) Black Hole X-ray Binary Cyg X-1 (VLA+NuSTAR) Tetarenko (Sivakoff, Tetarenko) + Tetarenko (Sivakoff, Tetarenko) + 2019 2019 Kaspi_RadioTransients_LRP2020 16 21CM COSMOLOGY IN CANADA Adrian Liu, McGill University Liu_21cm_cosmology LRP Town Hall, 1st November 201917 What’s our mission? Liu_21cm_cosmology 18 Hydrogen is everywhere, and the 21cm line allows us to trace hydrogen Emit radio wave with 21cm wavelength Absorb radio wave with 21cm wavelength Liu_21cm_cosmology 19 We have yet to observe most of the observable Universe “r=ct” Liu_21cm_cosmology 20 We have yet to observe most of the observable Universe “r=ct” Liu_21cm_cosmology 21 Spatial patterns vs… Angle on sky Liu_21cm_cosmology 22 Spatial patterns vs… Average over sky Pritchard & Loeb (2010) … the mean (“global”) signal? Liu_21cm_cosmology 23 What’s the status of the field? Liu_21cm_cosmology 24 • At low redshifts (z < 6; post-reionization): • Positive detections of spatial fluctuations in cross-correlations at z ~ 0 and z ~0.8 • At high redshifts (z > 6; during or before reionization): • Increasingly stringent upper limits on spatial fluctuations. • A possible detection of the global signal at z ~ 17 (still needs to be checked!) Liu_21cm_cosmology 25 Masui et al. (2013) Liu_21cm_cosmology 26 • At low redshifts (z < 6; post-reionization): • Positive detections of spatial fluctuations in cross-correlations at z ~ 0 and z ~0.8 • At high redshifts (z > 6; during or before reionization): • Increasingly stringent upper limits on spatial fluctuations. • A possible detection of the global signal at z ~ 17 (still needs to be checked!) Liu_21cm_cosmology 27 Compilation from Liu & Shaw (2019) Liu_21cm_cosmology 28 • At low redshifts (z < 6; post-reionization): • Positive detections of spatial fluctuations in cross-correlations at z ~ 0 and z ~0.8 • At high redshifts (z > 6; during