A white dwarf merger as progenitor of the anomalous X-ray pulsar 4U 0142+61?

Understand

It has been recently proposed that massive fast-rotating highly-magnetized white dwarfs could describe the observational properties of some of Soft Gamma-Ray Repeaters (SGRs) and Anomalous X-Ray Pulsars (AXPs).

• Moreover, it has also been shown that high-field magnetic (HFMWDs) can be the outcome of white dwarf binary mergers.
• The products of these mergers consist of a hot central white dwarf surrounded by a rapidly rotating disk.
• Here we show that the merger of a double degenerate system can explain the characteristics of the peculiar AXP 4U 0142+61.