The McGill Magnetar Catalog

TLDR: In this paper, the authors present a catalog of the 26 currently known magnetars and magnetar candidates, and investigate and plot possible correlations between their timing, X-ray, and multiwavelength properties.

Abstract: We present a catalog of the 26 currently known magnetars and magnetar candidates. We tabulate astrometric and timing data for all catalog sources, as well as their observed radiative properties, particularly the spectral parameters of the quiescent X-ray emission. We show histograms of the spatial and timing properties of the magnetars, comparing them with the known pulsar population, and we investigate and plot possible correlations between their timing, X-ray, and multiwavelength properties. We find the scale height of magnetars to be in the range 20-31 pc, assuming they are exponentially distributed. This range is smaller than that measured for OB stars, providing evidence that magnetars are born from the most massive O stars. From the same fits, we find that the Sun lies ~13-22 pc above the Galactic plane, consistent with previous measurements. We confirm previously identified correlations between quiescent X-ray luminosity L_X and magnetic field B, as well as X-ray spectral power-law index Gamma and B, and show evidence for an excluded region in a plot of L_X vs. Gamma. We also present an updated kT versus characteristic age plot, showing magnetars and high-B radio pulsars are hotter than lower-B neutron stars of similar age. Finally, we observe a striking difference between magnetars detected in the the hard X-ray and radio bands; there is a clear correlation between the hard and soft X-ray flux, whereas the radio-detected magnetars all have low soft X-ray flux suggesting, if anything, that the two bands are anti-correlated. An online version of the catalog is located at this http URL