Dust Formation in a Galaxy with Primitive Abundances
G. C. Sloan,1*
M. Matsuura,2,3
A. A. Zijlstra,4
E. Lagadec,4
M. A. T. Groenewegen,5
P. R. Wood,6
C. Szyszka,4
J. Bernard-Salas,1
J. Th. van Loon7
Interstellar dust plays a crucial role in the evolution of galaxies.
It governs the chemistry and physics of the interstellar medium.
In the local universe, dust forms primarily in the ejecta from
stars, but its composition and origin in galaxies at very early
times remain controversial. We report observational evidence
of dust forming around a carbon star in a nearby galaxy with
a low abundance of heavy elements, 25 times lower than the solar
abundance. The production of dust by a carbon star in a galaxy
with such primitive abundances raises the possibility that carbon
stars contributed carbonaceous dust in the early universe.
2 National Optical Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan.
3 Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
4 School of Physics and Astronomy, University of Manchester, Post Office Box 88, Manchester M6O 1QD, UK.
5 Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussels, Belgium.
6 Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek Australian Capital Territory 2611, Australia.
7 Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG, UK.
* To whom correspondence should be addressed. E-mail: sloan{at}isc.astro.cornell.edu
