SCYON Abstract

Received on January 5 2001

Detection of Massive Tidal Tails around the Globular Cluster Pal 5 with
SDSS Commissioning Data

AuthorsM. Odenkirchen1, E.K. Grebel1, C.M. Rockosi2, W. Dehnen1, R. Ibata1, H.-W. Rix1, A. Stolte1, , C. Wolf1, J.E. Anderson Jr.3, N.A. Bahcall4, J. Brinkmann5, I. Csabai6, G. Hennessy7, R.B. Hindsley8, Z. Ivezic4
Affiliation1Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany
2University of Chicago, Dept. of Astronomy & Astrophysics, 5640 South Ellis Ave., Chicago, IL 60637
3Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510
4Princeton University Observatory, Princeton, NJ 08544
5Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349-0059
6Dept. of Physics & Astronomy, The Johns Hopkins University, 3701 San Martin Drive, Baltimore, MD 21218
7U.S. Naval Observatory, 3450 Massachusetts Ave. NW, Washington, DC~20392-5420
8Naval Research Lab, 4555 Overlook Ave. SW, Washington, DC 20375
9U.S. Naval Observatory, Flagstaff Station, P.O. Box 1149, Flagstaff, AZ 86002-1149
Accepted byThe Astrophysical Journal Letters


We report the discovery of two well-defined tidal tails emerging from the sparse remote globular cluster Palomar 5. These tails stretch out symmetrically to both sides of the cluster in the direction of constant Galactic latitude and subtend an angle of 2.6° on the sky. The tails have been detected in commissioning data of the Sloan Digital Sky Survey (SDSS), providing deep five-color photometry in a 2.5° wide band along the equator. The stars in the tails make up a substantial part (~ 1/3) of the current total population of cluster stars in the magnitude interval 19.5 < i* < 22.0. This reveals that the cluster is subject to heavy mass loss. The orientation of the tails provides an important key for the determination of the cluster's Galactic orbit.