We report the discovery of an isolated millisecond pulsar M15O (J2129+1210O)
from the globular cluster M15 (NGC 7078) with a period of $\sim$11.06686 ms and
a dispersion measure of $\sim$67.44 cm$^{-3}$ pc. Its spin period is so close
to the $10^{\text{th}}$ harmonic of the bright pulsar M15A ($\sim$11.06647 ms)
and thus missed in previous pulsar search. We suggest adding the spectrum in
the pulsar candidate diagnostic plot to identify new signals near the
harmonics. M15O has the first spin frequency derivative and the second spin
frequency derivative,being 1.79191(5) $\times$ $10^{-14}$ Hz $s^{-2}$ E
3.3133(6)$\times$ $10^{-23}$ Hz $s^{-3}$, rispettivamente. Its projected distance
from the optical centre of M15 is the closest among all the pulsars in M15. The
origin can be something from the center of the massive and core-collapsed
globular cluster M15.

Questo articolo esplora i giri e le loro implicazioni.

Scarica PDF: