Palomar 13's Last Stand

Abstract

We present a proper motion and CCD photometric study of stars in the distant halo globular cluster Palomar 13. The absolute proper motion of Pal 13 with respect to the background galaxies, derived from moderate scale photographic plates separated by a 40-year baseline, is $({\mu }_{\alpha cos\delta },{\mu }_{\delta })=(+2.30,+0.27)\pm (0.26,0.25)$ milliarc-seconds per year. The resultant total space velocity (315 km s${}^{-1}$) implies that Pal 13 is in the inner part of its orbit near perigalacticon. Orbital integration reveals the cluster to possess an inclined, very eccentric, retrograde orbit. These data confirm that Pal 13 is a paradigm "young halo" globular cluster. The derived proper motions for cluster stars are used to produce membership probabilities and a cleaned CCD UBV catalogue for Pal 13. With this data set we have made small revisions to Pal 13's distance, metallicity, position and light profile. The membership of four previously reported RR Lyrae variables and a proportionally large group of blue straggler stars are confirmed. As expected, the blue stragglers are centrally concentrated. The small size of this cluster, combined with the shape of its light profile, which shows a clear departure from a classical King function beyond the tidal radius, suggests that Pal 13 is in the final throes of destruction. This could explain the large blue straggler specific frequency, as destructive processes would preferentially strip less massive stars.

54 pages, 9 figures, 7 tables, accapted for publication in February 2001 AJ

References in corpus (8)

• A giant stream of metal-rich stars in the halo of the galaxy M31
• The Present and Future Mass of the Milky Way Halo
• Exploring Halo Substructure with Giant Stars: I. Survey Description and Calibration of the Photometric Search Technique
• Exploring Halo Substructure with Giant Stars: II. Mapping the Extended Structure of the Carina Dwarf Spheroidal Galaxy
• Constraining the History of the Sagittarius Dwarf Galaxy Using Observations of its Tidal Debris
• The Absolute Proper Motion of Palomar 12: A Case for Tidal Capture from the Sagittarius Dwarf Spheroidal Galaxy
• Palomar 13's Last Stand
• Exploring the Leo II dSph I.: The Variable Star Content

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