  We use arguments developed in previous work to identify a second black hole
candidate associated with a M31 globular cluster, Bo 144, on the basis of X-ray
spectral and timing properties. The 2002 XMM-Newton observation of the
associated X-ray source (hereafter XBo 144) revealed behaviour that is common
to all low-mass X-ray binaries (LMXBs) in the low-hard state. Studies have
shown that neutron star LMXBs exhibit this behaviour at 0.01-1000 keV
luminosities <=10% of the Eddington limit (L_Edd). However, the unabsorbed
0.3-10 keV XBo 144 luminosity was ~0.30 L_Edd for a 1.4 M_sun neutron star, and
the expected 0.01-1000 keV luminosity is 3-7 times higher. We therefore
identify XBo 144 as a black hole candidate. Furthermore, it is the second black
hole candidate to be consistent with formation via tidal capture of a mean
sequence donor in a GC; such systems were previously though non-existent,
because the donor was thought to be disrupted during the capture process.
