A&A 436, 535-540 (2005)
The outermost cluster of M 31S. Galleti1, 2, M. Bellazzini2, L. Federici2 and F. Fusi Pecci2
1 Università di Bologna, Dipartimento di Astronomia, via Ranzani 1, 40127 Bologna, Italy
2 INAF - Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
(Received 10 February 2005 / Accepted 1 March 2005)
We report on the identification of a new cluster in the far halo of the M 31 galaxy. The cluster, named Bologna 514 (B514) has an integrated magnitude , and a radial velocity, as estimated from two independent low-resolution spectra, km s-1, which fully confirms its membership to the M 31 system. The observed integrated spectrum is very similar to those of classical globular clusters. Being located at ( kpc in projected distance) from the center of the parent galaxy, B514 is by far the most remote M 31 cluster ever discovered. Its projected position, near the galaxy major axis, and M 31-centric velocity, similar to that observed in the outermost regions of the HI rotation curve, may indicate that it belongs to the subsystem of M 31 clusters that has been recently proposed (Morrison et al. 2004 ) to be part of the dynamically-cold thin disc of the galaxy.
Key words: galaxies: Local Group -- galaxies: star clusters -- galaxies: kinematics and dynamics -- galaxies: spiral
© ESO 2005