Discovery and timing of pulsars in the globular cluster M13 with FAST
  We report the discovery of a binary millisecond pulsar (namely PSR
J1641+3627F or M13F) in the globular cluster M13 (NGC 6205) and timing
solutions of M13A to F using observations made with the Five-hundred-metre
Aperture Spherical radio Telescope (FAST). PSR J1641+3627F has a spin period of
3.00 ms and an orbital period of 1.4 days. The most likely companion mass is
0.16 M$_{\odot}$. M13A to E all have short spin periods and small period
derivatives. We also confirm that the binary millisecond pulsar PSR
J1641$+$3627E (also M13E) is a black widow with a companion mass around 0.02
M$_{\odot}$. We find that all the binary systems have low eccentricities
compared to those typical for globular cluster pulsars and that they decrease
with distance from the cluster core. This is consistent with what is expected
as this cluster has a very low encounter rate per binary.
