We present a model of globular cluster (GC) self-enrichment.
In this model, the final metallicity depends on
the pressure exerted by the hot protogalactic medium on the
proto-globular cluster clouds (PGCCs) and consequently
on their location in the protogalaxy. Our model is therefore able to
explain the metallicity gradient observed in the Old Halo globular
One of the main argument used against
the hypothesis of self-enrichment in GCs is the supernova energetics,
namely the ability of a small number of supernovae to disrupt PGCCs.
However, with a simple self-enrichment model, Parmentier et al.
(Section 5, this meeting) have shown that this idea may not be true,
because only a fraction of the kinetic energy of the Type II supernova
ejecta is deposited as kinetic energy of the ISM. The kinetic energy of
the supershell, pushed by several tens or even hundreds of SNeII, can be
less than the binding energy of the PGCC once the shell has reached the
edge of the PGCC. We now go a step further and investigate an important
consequence of this self-enrichment model.
Dinescu, D.I., Girard, T.M., Van Altena, W.F., 1999, AJ 117, 1792
Dopita M.A., Smith G.H., 1986, ApJ 304, 283
Harris W.E., 1996, AJ 112, 1487
Lee Y.W., Demarque, P., Zinn R., 1994, ApJ 423, 248
Murray S.D., Lin D.N.C., 1992, ApJ 400, 265
Parmentier G., Jehin E., Magain P., Neuforge C., Noels A. and
A.A. Thoul, 1999, accepted for publication in A&A
Zinn, R., 1992, Graeme H. Smith, Jean P.Brodie, eds, ASP Conference
Series, Volume 48, The globular clusters-galaxy connection, p 38
Institut d'Astrophysique et de
Géophysique de l'
Université de Liège
Avenue de Cointe, 5
B-4000 Liège, BELGIQUE
Tel: +32 (0)4 252.99.80
Fax: +32 (0)4 252.74.74
Last modification: October,26 2000.