Long-period radio transients are a new class of astrophysical objects that exhibit periodic radio emission on timescales of tens of minutes. Their true nature remains unknown; possibilities include magnetic white dwarfs, binary systems, or long-period magnetars; the latter class is predicted to produce fast radio bursts (FRBs). Using the MeerKAT radio telescope, we conducted follow-up observations of the long-period radio transient GPM J1839-10.
View Article and Find Full Text PDFMagnetars-highly magnetized neutron stars-are thought to be the most likely progenitors for fast radio bursts (FRBs). Freely precessing magnetars are further invoked to explain the repeating FRBs. We report here on new high-cadence radio observations of the magnetar XTE J1810-197 recorded shortly after an X-ray outburst.
View Article and Find Full Text PDFSome compact objects observed in gravitational wave events have masses in the gap between known neutron stars (NSs) and black holes (BHs). The nature of these mass gap objects is unknown, as is the formation of their host binary systems. We report pulsar timing observations made with the Karoo Array Telescope (MeerKAT) of PSR J0514-4002E, an eccentric binary millisecond pulsar in the globular cluster NGC 1851.
View Article and Find Full Text PDFSeveral long-period radio transients have recently been discovered, with strongly polarized coherent radio pulses appearing on timescales between tens to thousands of seconds. In some cases, the radio pulses have been interpreted as coming from rotating neutron stars with extremely strong magnetic fields, known as magnetars; the origin of other, occasionally periodic and less-well-sampled radio transients is still debated. Coherent periodic radio emission is usually explained by rotating dipolar magnetic fields and pair-production mechanisms, but such models do not easily predict radio emission from such slowly rotating neutron stars and maintain it for extended times.
View Article and Find Full Text PDF