Long-period radio transient PSR J0901-4046 is not an Isolated White Dwarf Pulsar

Abstract

We report the {\it Chandra} non-detection of PSR J0901$-$4046, a $P=75.89$ seconds long-period radio transient (LPT). For a distance of 467 pc, the upper limit on X-ray luminosity is $L_X\le$ few $\times 10^{28}$ erg s${}^{-1}$. For the measured $P$ and $\dot{P}$, this upper limit, approximately 50 times lower than the previous {\it Swift} observations, is comparable to the spin-down luminosity of a neutron star, but would be approximately four orders of magnitude smaller than the spindown power of a white dwarf. Our results disfavor isolated WDs as the central star in PSR J0901$-$4046. We suggest that the isolated LPTs are powered by magnetic dissipation (not rotation), in a way similar to magnetars' radio emission.