First Discovery of New Pulsars and RRATs with CHIME/FRB

We report the discovery of seven new Galactic pulsars with the Canadian Hydrogen Intensity Mapping Experiment’s Fast Radio Burst (CHIME/FRB) backend. These sources were first identified via single pulses in CHIME/FRB, then followed up with CHIME/Pulsar. Four sources appear to be rotating radio transients, pulsar-like sources with occasional single-pulse emission with an underlying periodicity. Of those four sources, three have detected periods ranging from 220 ms to 2.726 s. Three sources have more persistent but still intermittent emission and are likely intermittent or nulling pulsars. We have determined phase-coherent timing solutions for the latter two. These seven sources are the first discovery of previously unknown Galactic sources with CHIME/FRB and highlight the potential of fast radio burst detection instruments to search for intermittent Galactic radio sources.

FIGARO simulation: FIlaments & GAlactic RadiO simulation

We produce the first low to mid-frequency radio simulation that incorporates both traditional extragalactic radio sources as well as synchrotron cosmic web emission. The FIlaments & GAlactic RadiO (FIGARO) simulation includes 10 unique 4° × 4° fields, incorporating active galactic nucleii (AGNs), star-forming galaxies (SFGs), and synchrotron cosmic web emission out to a redshift of z = 0.8 and over the frequency range 100–1 400 MHz. To do this, the simulation brings together a recent 1003 Mpc3 magnetohydrodynamic simulation (Vazza et al. 2019, A&A, 627, A5), calibrated to match observed radio relic population statistics, alongside updated ‘T-RECS’ code for simulating extragalactic radio sources (Bonaldi et al. 2019, MNRAS, 482, 2). Uniquely, the AGNs and SFGs are populated and positioned in accordance with the underlying matter density of the cosmological simulation. In this way, the simulation provides an accurate understanding of the apparent morphology, angular scales, and brightness of the cosmic web as well as—crucially—the clustering properties of the cosmic web with respect to the embedded extragalactic radio population. We find that the synchrotron cosmic web does not closely trace the underlying mass distribution of the cosmic web, but is instead dominated by shocked shells of emission surrounding dark matter halos and resembles a large, undetected population of radio relics. We also show that, with accurate kernels, the cosmic web radio emission is clearly detectable by cross-correlation techniques and this signal is separable from the embedded extragalactic radio population. We offer the simulation as a public resource towards the development of techniques for detecting and measuring the synchrotron cosmic web.

AGN astrometry: A powerful tool for galaxy kinematic studies

This article highlights the successes of the high resolution astrometric VLBI observations used for measuring proper motion of galaxies in the Local group. The required, high accuracies, often in the μ as yr−1 regime, are only attainable through the use of the phase-referencing technique. These require either a compact radio source (AGN) or strong maser emission in the target galaxy and, additionally, some compact extra-galactic radio sources (quasars) to serve as ideal background reference source. The derived proper motions can lead to lower limits on the orbital lower estimates to the mass of the host galaxy, promise a new handle on dynamical models of interacting galaxy systems and offer insights on the spatial distribution of dark matter in the near universe.

Updated Calibration of the LOFAR Low-Band Antennas

The LOw-Frequency ARray (LOFAR) telescope measures radio emission from air showers. In order to interpret the data, an absolute, frequency dependent calibration is required. Due to a growing need for a better understanding of the measured frequency spectrum, we revisit the calibration of the LOFAR antennas in the range of 30—80 MHz. Using the galactic radio emission and a detailed model of the LOFAR signal chain, we find a calibration that provides an absolute energy scale and allows us to study frequency dependent features in measured air shower signals.

EoR Foregrounds: the Faint Extragalactic Radio Sky

A wealth of new data from upgraded and new radio interferometers are rapidly improving and transforming our understanding of the faint extra-galactic radio sky. Indeed the mounting statistics at sub-mJy and μJy flux levels is finally allowing us to get stringent observational constraints on the faint radio population and on the modeling of its various components. In this paper I will provide a brief overview of the latest results in areas that are potentially important for an accurate treatment of extra-galactic foregrounds in experiments designed to probe the Epoch of Reionization.