Discovery of a Candidate Binary Supermassive Black Hole in a Periodic Quasar from Circumbinary Accretion Variability

Kavli Affiliate: R. G. McMahon | Summary:Binary supermassive black holes (BSBHs) are expected to be a generic byproduct from hierarchical galaxy formation. The final coalescence of BSBHs is thought to be the loudest gravitational wave (GW) siren, yet no confirmed BSBH is known in the GW-dominated regime. While periodic quasars have been proposed as BSBH […]


Continue.. Discovery of a Candidate Binary Supermassive Black Hole in a Periodic Quasar from Circumbinary Accretion Variability

Precision Measurement of the Beam-Normal Single-Spin Asymmetry in Forward-Angle Elastic Electron-Proton Scattering

Kavli Affiliate: A. C. Davis | Summary:A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of […]


Continue.. Precision Measurement of the Beam-Normal Single-Spin Asymmetry in Forward-Angle Elastic Electron-Proton Scattering

The correlation of high-redshift galaxies with the thermal Sunyaev-Zel’dovich effect traces reionization

Kavli Affiliate: Martin Haehnelt | First 5 Authors: Eric J. Baxter, Lewis Weinberger, Martin Haehnelt, Vid Iršič, Girish Kulkarni | Summary: We explore a potential new probe of reionization: the cross-correlation of high-redshift galaxies with maps of the thermal Sunyaev-Zel’dovich (tSZ) effect. We consider two types of high redshift galaxies: Lyman break galaxies (LBGs) and […]


Continue.. The correlation of high-redshift galaxies with the thermal Sunyaev-Zel’dovich effect traces reionization

Optimizing neutron moderators for a spallation-driven ultracold-neutron source at TRIUMF

Kavli Affiliate: A. C. Davis | Summary:We report on our efforts to optimize the geometry of neutron moderators and converters for the TRIUMF UltraCold Advanced Neutron (TUCAN) source using MCNP simulations. It will use an existing spallation neutron source driven by a 19.3 kW proton beam delivered by TRIUMF’s 520 MeV cyclotron. Spallation neutrons will […]


Continue.. Optimizing neutron moderators for a spallation-driven ultracold-neutron source at TRIUMF

Parity-Violating Inelastic Electron-Proton Scattering at Low $Q^2$ Above the Resonance Region

Kavli Affiliate: A. C. Davis | Summary:We report the measurement of the parity-violating asymmetry for the inelastic scattering of electrons from the proton, at $Q^2 = 0.082$ GeV$^2$ and $ W = 2.23$ GeV, above the resonance region. The result $A_rm Inel = – 13.5 pm 2.0 (rm stat) pm 3.9 (rm syst)$~ppm agrees with […]


Continue.. Parity-Violating Inelastic Electron-Proton Scattering at Low $Q^2$ Above the Resonance Region

Catalogues of Active Galactic Nuclei From Gaia and unWISE Data

Kavli Affiliate: R. G. McMahon | First 5 Authors: Yiping Shu, Sergey E. Koposov, N. Wyn Evans, Vasily Belokurov, Richard G. McMahon | Summary: We present two catalogues of active galactic nucleus (AGN) candidates selected from the latest data of two all-sky surveys — Data Release 2 (DR2) of the emph{Gaia} mission and the unWISE […]


Continue.. Catalogues of Active Galactic Nuclei From Gaia and unWISE Data

Catalogues of Active Galactic Nuclei From Gaia and unWISE Data

Kavli Affiliate: R. G. McMahon | Summary:We present two catalogues of active galactic nucleus (AGN) candidates selected from the latest data of two all-sky surveys — Data Release 2 (DR2) of the emphGaia mission and the unWISE catalogue of the emphWide-field Infrared Survey Explorer (emphWISE). We train a random forest classifier to predict the probability […]


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A fast-switching magnet serving a spallation-driven ultracold neutron source

Kavli Affiliate: A. C. Davis | Summary:A fast-switching, high-repetition-rate magnet and power supply have been developed for and operated at TRIUMF, to deliver a proton beam to the new ultracold neutron (UCN) facility. The facility possesses unique operational requirements: a time-averaged beam current of 40~$μ$A with the ability to switch the beam on or off […]


Continue.. A fast-switching magnet serving a spallation-driven ultracold neutron source