SCYON Abstract

Received on March 13 2009

A peculiar HI cloud near the distant globular cluster Pal 4

AuthorsJacco Th. van Loon (1), Snezana Stanimirovic (2), Mary Putman (3), Joshua E.G. Peek (4), Steven J. Gibson (5), Kevin A. Douglas (6), and Eric J. Korpela (7)
Affiliation(1) Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG, United Kingdom
(2) Department of Astronomy, University of Wisconsin, Madison, WI 53706, USA
(3) Department of Astronomy, Columbia University, New York, NY 10027, USA
(4) Department of Astronomy, UC Berkeley, 601 Campbell Hall, Berkeley, CA 94720, USA
(5) Department of Physics & Astronomy, Western Kentucky University, Bowling Green, KY 42101, USA
(6) Astrophysics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom
(7) Space Sciences Laboratory, UC Berkeley, 601 Campbell Hall, Berkeley, CA 94720, USA
Accepted byMonthly Notices of the Royal Astronomical Society
Contactjacco@astro.keele.ac.uk
URLhttp://arXiv.org/abs/0903.2391
Links

Abstract

We present 21-cm observations of four Galactic globular clusters, as part of the on-going GALFA-HI Survey at Arecibo. We discovered a peculiar HI cloud in the vicinity of the distant (109 kpc) cluster Pal 4, and discuss its properties and likelihood of association with the cluster. We conclude that an association of the HI cloud and Pal 4 is possible, but that a chance coincidence between Pal 4 and a nearby compact high-velocity cloud cannot be ruled out altogether. New, more stringent upper limits were derived for the other three clusters: M3, NGC 5466, and Pal 13. We briefly discuss the fate of globular cluster gas and the interaction of compact clouds with the Galactic Halo gas.