How rapidly do neutron stars spin at birth? Constaints from archival X-ray observations of extragalactic supernovae

Traditionally, studies aimed at inferring the distribution of birth periods of neutron stars are based on radio surveys. Here we propose an independent method to constrain the pulsar spin periods at birth based on their X-ray luminosities. In particular, the observed luminosity distribution of supernovae (SNe) poses a constraint on the initial rotational energy of the embedded pulsars, via the correlation found for radio pulsars, and under the assumption that this relation continues to hold beyond the observed range. We have extracted X-ray luminosities (or limits) for a large sample of historical SNe observed with Chandra, XMM and Swift, which have been firmly classified as core-collapse SNe. We have then compared these observational limits with the results of Monte Carlo simulations of the pulsar X-ray luminosity distribution for a range of values of the birth parameters. We find that a pulsar population dominated by millisecond periods at birth is ruled out by the data

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Mental health problems are on the rise among young adults in the U.S. (Kingkade, 2016). At the same time, today’s U.S. young adults are significantly more invested than their older counterparts in portraying themselves as “positive” (self-confident, easy-going, and happy; Berenson et al., 2018). Although many have begun to speculate that these two trends may be linked (e.g., Fagan, 2017), little empirical research on this issue exists