SCYON Abstract

Received on November 11 2005

Stellar mass loss and the Intra-Cluster Medium in Galactic globular clusters: a deep radio survey for HI and OH

AuthorsJacco Th. van Loon(1), Snezana Stanimirovic(2), A. Evans(1) and Erik Muller(3,4)
(1)Astrophysics Group, School of Physical & Geographical Sciences, Keele University, Staffordshire ST5 5BG, United Kingdom
(2)Radio Astronomy Lab, University of California at Berkeley, 601 Campbell Hall, Berkeley CA 94720, USA
(3)Arecibo Observatory, National Astronomy and Ionosphere Center, HC3 Box 53995, Arecibo PR 00612, USA
(4)CSIRO Australia Telescope National Facility, PO Box 76, Epping NSW 1710, Australia
Accepted byMonthly Notices of the Royal Astronomical Society


We present the results of a survey, the deepest to date, for HI emission at 21 cm and OH emission at 18 cm (lines at 1612, 1665, 1667 and 1720 MHz) in the direction towards the Galactic globular clusters M15, M2, NGC 6934, NGC 7006 and Pal 13. The aim is to measure the amount of hydrogen in the intra-cluster medium (ICM), and to find OH masers in the circumstellar envelopes of globular cluster red giants. We present a tentative detection of 0.3 M(sun) of neutral hydrogen in M15 and possible detections of neutral hydrogen in M2 and Pal 13. We derive upper limits to the neutral hydrogen content of NGC 6934 and NGC 7006. No OH emission is detected. We also present deep HI data of the northern tip of the Magellanic Stream behind Pal 13.