We have obtained spectra for globular cluster candidates in M104 with LDSS-2 on the William Herschel Telescope , confirming 34 objects as M104 globular clusters .
We find a cluster velocity dispersion of \sim 260 km/sec , and the Projected Mass Estimator gives a mass of 5.0 ( 3.5,6.7 ) \times 10 ^ { 11 } M _ { \odot } for M104 within a projected radius of \sim 330 ^ { \prime \prime } ( 14 kpc for D=8.55 Mpc ) .
Our best estimate for the mass-to-light ratio is M/L _ { V _ { T } } = 16 ^ { +5.5 } _ { -5.0 } within the same radius .
Considering all of the possible sources of uncertainty , we find a lower limit of M/L _ { V } = 5.3 , which is larger than the M/L _ { V } found from rotation curve analyses inside 180 ^ { \prime \prime } .
We thus conclude that the mass-to-light ratio increases with radius , or in other words that M104 possesses a dark matter halo .
There is a marginal detection of rotation in the M104 cluster system at the 92.5 % confidence level ; larger samples will be needed to investigate this possibility .
Interestingly , the M104 globular cluster and planetary nebulae ( PNe ) kinematics are roughly consistent inside \sim 100 ^ { \prime \prime } .
Finally , we find a mean cluster metallicity of [ Fe/H ] = - 0.70 \pm 0.3 , which is more typical of clusters in gE/cD galaxies than it is of clusters in other spirals .