MODEST Working Group 5:
Simulating Observations of Simulations of Young Dense Star Clusters (YoDeCs)

As an example of SOS we shows two synthetic ``ground-based images'' of a million-year-old star cluster near the Galactic center. Details of this simulation are published here. The initial conditions for this simulation were similar to the Arches cluster near the Galactic center. The initial cluster contained about 65000 stars selected from a Scalo (1986) initial mass function. Only stars which were originally members of the cluster are shown in the image; the (substantial) Galactic foreground and background are omitted for clarity. The ``knots'' in the left image are dense clumps in the tidal tail formed as the cluster dissolves in the Galactic field. Assessing the observability of these tidal tails will be an important component of our analysis program. The frame below shows a higher-resolution image of the cluster itself. Left: An animation of this cluster, created using partiview is available on the Starlab Web site, where additional examples may be found.

Left: Magnified detail of the simulated CCD of a simulation of the Arches cluster

This simulated UV spectrum is taken from a 6.7Myr old star cluster of 131072 stars from a Salpeter mass function. The initial conditions ware to mimick the 7-12Myr old star cluster MGG-11 in the irregular galaxy M82. The spectra are created by Houria Belkus and Joris van Bever and using the Brussels spectral synthesis code. The black curve represents the spectra for all stars in the cluster, the blue curve is only for the stars in the cluster core. There is an apparent difference in the spectra of the entire star cluster and the core of the P Cygni lines CIV 1550 en NIV 1720 Angstrom.

The two spectra to the left are from the same cluster at zero age and at an age of 12 Myr.