Vol. 572
In section 7. Stellar structure and evolution

LOFAR observations of PSR B0943+10: profile evolution and discovery of a systematically changing profile delay in bright mode

by A. Bilous, J. Hessels, V. Kondratiev, et al. A&A 572, A52


Mode switching, the almost discontinuous flipping of a pulsar between two distinct emission levels, is seen in a small population of pulsars. This paper studies one of the best examples, PSR B0943+10, using LOFAR 25-80 MHz and 110-190 MHz) observations.The authors use the profile to specify the structure of the emission region. (One feature of the pulses is a mapping between the frequency of the emission and its site of origin in the magnetosphere.) The observed B-mode profile delay is frequency-independent and is far too large for the spin-down rate; it may be a gradual movement of the emission cone, unlike the spin involving emission from different field lines. The observed profile delay and variation of the subpulse drift rate have similar dependence on time.