A Double Globular Cluster in M31

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Session 76 -- Spirals I
Display presentation, Wednesday, 11, 1995, 9:20am - 6:30pm

[76.07] A Double Globular Cluster in M31

Stephen Holland, G. G. Fahlman, \& H. B. Richer (UBC)

The globular cluster (GC) G185, located 1\farcm7 south of the center of M31, is shown to have a companion GC approximately 4\arcsec~to the NE. While several multiple GCs have have been observed in the Magellanic Clouds none have been found in an old GC system. We estimate the probability of such a chance line-of-sight alignment near the nucleus of M31 to be 0.016 yet find no obvious indication of any tidal deformation in either cluster as would be expected if the clusters were interacting.

Two-dimensional modelling suggests G185 has a King [(1966) {\sl AJ}, 71 , 64] concentration of $c = 1.2 \pm 0.1$ while the companion has $c = 0.55 \pm 0.10$ and is physically smaller than G185. Both objects have integrated dereddened colors of $({\sl V}-{\sl I}) \simeq 1.04$, similar to Galactic GCs. We will present isophotal analyses of both components of G185 as well as of van den Bergh 2, an apparently normal old GC located $\sim$1\arcmin~N of G185.

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