Tidal disruption and the tale of three clusters

New preprint :: NGC6397, NGC 6712, NGC 6218

Tidal disruption and the tale of three clusters
Authors:  Guido De Marchi (ESA), Francesco Paresce (INAF), Luigi Pulone (INAF)
Comments: Two pages, one figure, to appear in the proceedings of “Globular Clusters – Guides to Galaxies”, eds. T. Richtler and S. Larsen

 How well can we tell whether a globular cluster will survive the Galaxy’s tidal forces? This is conceptually easy to do if we know the cluster’s total mass, mass structure and space motion parameters. This information is used in models that predict the probability of disruption due to tidal stripping, disc and bulge shocking. But just how accurate is the information that goes into these models and, therefore, how reliable are their predictions? To understand the virtues and weaknesses of these models, we have studied in detail three globular clusters (NGC 6397, NGC 6712, NGC 6218) whose predicted interaction with the galaxy is very different. We have used deep HST and VLT data to measure the luminosity function of stars throughout the clusters in order to derive a solid global mass function, which is the best tell-tale of the strength and extent of tidal stripping operated by the Galaxy. We indeed find that the global mass functions of the three clusters are different, but not in the way predicted by the models. [abridged]

URL : http://arxiv.org/abs/astro-ph/0702021

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s