Banting Research Foundation

Abstract Since fast radio bursts (FRBs) were discovered, their precise origins have remained a mystery. Multiwavelength observations of nearby FRB sources provide one of the best ways to make rapid progress in our understanding of the enigmatic FRB phenomenon. We present results from a sensitive, broadband multiwavelength X-ray and radio observational campaign of FRB 20200120E, the closest known extragalactic repeating FRB source. At a distance of 3.63 Mpc, FRB 20200120E resides in an exceptional location, within a ~10 Gyr-old globular cluster in the M81 galactic system. We place deep limits on both the persistent X-ray luminosity and prompt X-ray emission at the time of radio bursts from FRB 20200120E, which we use to constrain possible progenitors for the source. We compare our results to various classes of X-ray sources and transients. In particular, we find that FRB 20200120E is unlikely to be associated with: ultraluminous X-ray bursts (ULXBs), similar to those observed from objects of unknown origin in other extragalactic globular clusters; giant flares, like those observed from Galactic and extragalactic magnetars; or most intermediate flares and very bright short X-ray bursts, similar to those seen from magnetars in the Milky Way. We show that FRB 20200120E is also unlikely to be powered by a persistent or transient ultraluminous X-ray (ULX) source or a young, extragalactic pulsar embedded in a Crab-like nebula. We also provide new constraints on the compatibility of FRB 20200120E with accretion-based FRB models involving X-ray binaries and models that require a synchrotron maser process from relativistic shocks to generate FRB emission. These results highlight the power that multiwavelength observations of nearby FRBs can provide for discriminating between potential FRB progenitor models.

We have discovered a 2.5 Mpc (projected) long filament of infrared-bright galaxies connecting two of the three ~5x10^14 Msun clusters making up the RCS 2319+00 supercluster at z=0.9. The filament is revealed in a deep Herschel Spectral and Photometric Imaging REceiver (SPIRE) map that shows 250-500um emission associated with a spectroscopically identified filament of galaxies spanning two X-ray bright cluster cores. We estimate that the total (8-1000um) infrared luminosity of the filament is Lir~5x10^12 Lsun, which, if due to star formation alone, corresponds to a total SFR 900 Msun/yr. We are witnessing the scene of the build-up of a >10^15 Msun cluster of galaxies, seen prior to the merging of three massive components, each of which already contains a population of red, passive galaxies that formed at z>2. The infrared filament demonstrates that significant stellar mass assembly is taking place in the moderate density, dynamically active circumcluster environments of the most massive clusters at high-redshift, and this activity is concomitant with the hierarchical build-up of large scale structure.

Acta PaediatricaVolume 54, Issue 4 p. 369-374 Variations in Oxygen Consumption in the Infant with Hypoxaemia due to Cardiopulmonary Disease Henry LEVISON, Henry LEVISON Research Institute of The Hospital for Sick Children and the Department of Paediatrics, University of Toronto, Canada Banting Research Fellow.Search for more papers by this authorMaria DELIVORIA, Maria DELIVORIA Research Institute of The Hospital for Sick Children and the Department of Paediatrics, University of Toronto, CanadaSearch for more papers by this authorPAPADOPOULOS PAUL R. SWYER, PAPADOPOULOS PAUL R. SWYER Research Institute of The Hospital for Sick Children and the Department of Paediatrics, University of Toronto, CanadaSearch for more papers by this author Henry LEVISON, Henry LEVISON Research Institute of The Hospital for Sick Children and the Department of Paediatrics, University of Toronto, Canada Banting Research Fellow.Search for more papers by this authorMaria DELIVORIA, Maria DELIVORIA Research Institute of The Hospital for Sick Children and the Department of Paediatrics, University of Toronto, CanadaSearch for more papers by this authorPAPADOPOULOS PAUL R. SWYER, PAPADOPOULOS PAUL R. SWYER Research Institute of The Hospital for Sick Children and the Department of Paediatrics, University of Toronto, CanadaSearch for more papers by this author First published: July 1965 https://doi.org/10.1111/j.1651-2227.1965.tb06386.xCitations: 9 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume54, Issue4July 1965Pages 369-374 RelatedInformation