Extended Data Fig. 9: X-ray luminosity constraint of ZTF J1406+1222.
From: A 62-minute orbital period black widow binary in a wide hierarchical triple
The 0.2–10 keV X-ray luminosity, LX, versus \(\dot{E}\) for known black widow systems16,84 (detections shown as black circles and upper limits as red triangles). The red dashed line indicates the region to which we have constrained ZTF J1406+1222, on the basis of the X-ray luminosity upper limit derived from our Swift observation and the estimate of Ė based on the peak temperature of the irradiated face of the neutron star’s companion. Several known millisecond pulsars with a similar Ė are currently below our X-ray flux upper limit, and thus deeper observations may yield an X-ray detection of ZTF J1406+1222.
