Free access article

Issue A&A Volume 377, Number 2, October II 2001 Page(s) 425 - 427 Section Extragalactic astronomy DOI 10.1051/0004-6361:20011128

A&A 377, 425-427 (2001)
DOI: 10.1051/0004-6361:20011128

The enigma in the heart of Ursa Minor

S. Demers¹ and P. Battinelli<sup>2

1</sup>  Département de Physique, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada
²  Osservatorio Astronomico di Roma Viale del Parco Mellini 84, 00136 Roma, Italy
    e-mail: battinel@oarhp1.rm.astro.it

(Received 18 June 2001 / Accepted 9 August 2001)

Abstract
To investigate the physical nature of the observed deficiency of stars in the very center of the Ursa Minor Dwarf Spheroidal galaxy, we recently obtained JCMT-SCUBA 850 m photometry of this region. The observed void could be explained by 0.5 mag of extinction. While the amount of dust needed to produce such absorption (under certain assumptions for the dust temperature and the exponent in the dust emissivity term) would yield a 5 mJy signal -easily detectable by SCUBA -we found no signal at 850 m, after 256 min of integration. This finding rules out the presence of a few solar masses of cold dust cloud as the explanation for the central lack of stars observed in Ursa Minor. We discuss possible explanations.

Key words: galaxies: individual: Ursa Minor -- galaxies: ISM -- ISM: dust, extinction

Offprint request: S. Demers, demers@astro.umontreal.ca

SIMBAD Objects

© ESO 2001

What is OpenURL?