GCRT J1745-3009 AS A TRANSIENT WHITE DWARF PULSAR

摘要

A transient radio source in the direction of the Galactic center, GCRT J1745 —3009, exhibited five peculiar consecutive outbursts at 0.33 GHz with a period of 77.13 minutes and a duration of ～ 10 minutes for each outburst. It has been claimed to be the prototype of a hitherto unknown class of transient radio sources. We interpret it as a transient white dwarf pulsar with a period of 77.13 minutes. The ～10 minute flaring duration corresponds to the epoch in which the radio beam sweeps our line of sight. The bursting epoch corresponds to the episodes in which stronger sunspot-like magnetic fields emerge into the white dwarf polar cap region during which the pair-production condition is satisfied and the white dwarf behaves like a radio pulsar. It switches off as the pair-production condition breaks down.