The bifurcated emission component ( BEC ) in the radio profile of the millisecond pulsar J1012 + 5307 can be interpreted as the signature of the curvature radiation beam polarised orthogonally to the plane of electron trajectory .
Since the beam is intrinsically narrow ( \sim \kern - 1.991693 pt 1 ^ { \circ } ) , the associated emission region must be small for the observed BEC to avoid smearing out by spatial convolution .
We estimate whether the energy available in the stream is sufficient to produce such a bright feature in the averaged profile .
The energy considerations become complicated by the angular constraints imposed by the width of the microbeam , and by the specific spectrum of the BEC which is found to have the spectral index \xi _ { \scriptscriptstyle BEC } \approx - 0.9 in comparison to the index of \xi \approx - 2 for the total profile .
For typical parameters , the luminosity of the BEC is determined to be 4 10 ^ { 25 } erg/s , whereas the maximum-possible beam-size-limited power of the stream is L _ { \scriptscriptstyle \Delta \Phi } \approx 2 10 ^ { 29 } erg/s .
This implies the minimum energy-conversion efficiency of \eta _ { \scriptscriptstyle \Delta \Phi } \approx 2 10 ^ { -4 } .
The BEC ’ s luminosity does not exceed any absolute limits of energetics , in particular , it is smaller than the power of primary electron and/or secondary plasma stream .
However , the implied efficiency of energy transfer into the radio band is extreme if the coherently emitting charge-separated plasma density is limited to the Goldreich-Julian value .
This suggests that the bifurcated shape of the BEC has macroscopic origin , however , several uncertainties ( eg .
the dipole inclination and spectral shape ) make this conclusion not firm .