NOAO >   Observing Info >   Approved Programs >   2010A-0088

Small NOAO Logo

Proposal Information for 2010A-0088


PI: Rodrigo Ibata, Observatoire de Strasbourg, ibata@astro.u-strasbg.fr
Address: Universite de Strasbourg, 11, rue de l'universite, Strasbourg 67000, France

CoI: Anjali Varghese, Observatoire de Strasbourg
CoI: Mike Irwin, Institute of Astronomy, Cambridge
CoI: Geraint Lewis, University of Sydney
CoI: Scott Chapman, Institute of Astronomy, Cambridge

Title: What is the nature of the dark matter: cold or warm? Imprints on the tidal stream of Pal 5

Abstract: We request KPNO/MOSAIC to complete a survey of the extremely extended tidal tails of the disrupting globular cluster Palomar 5. If dark matter is cold, hundreds of dense clumps of masses above 10^7 \rm M_\odot were formed early on in the Universe, and were later incorporated into the Galaxy. Most of these clumps may never have formed any stars (or any significant number of stars), and could therefore be completely dark. However, we have shown that the dark lumps do leave a clear imprint on dynamically cold tidal streams. In 2008 and 2009 we undertook a VLT/FLAMES survey to examine whether this expected heating has occurred or not, but unfortunately our sample is rendered useless by contaminating foreground dwarf stars. Here we request time to use the Washington + DDO51 filters to reject contaminants in our spectroscopic and photometric samples, allowing us to attain our science goal of determining whether the tidal stream of Palomar 5 has indeed been kinematically heated by interactions with dark matter mini-halos.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2010A-0088

noaoprop-help@noao.edu

Small NOAO Logo