Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamical mass of a star cluster in M83: a test of fibre-fed
  multi-object spectroscopy   (Abridged) Aims: We obtained VLT/FLAMES+UVES high-resolution, fibre-fed
spectroscopy (FFS) of five young massive clusters in M83 (NGC 5236). This forms
the basis of a pilot study testing the feasibility of using FFS to measure the
velocity dispersions of several clusters simultaneously, in order to determine
their dynamical masses; Methods: We adopted two methods for determining the
velocity dispersion of the star clusters: cross-correlating the cluster
spectrum with the template spectra and minimising a chi^2 value between the
cluster spectrum and the broadened template spectra. Cluster 805 in M83 was
chosen as a control to test the reliability of the method, through a comparison
with the results obtained from a standard echelle VLT/UVES spectrum obtained by
Larsen & Richtler; Results: We find no dependence of the velocity dispersions
measured for a cluster on the choice of red giant versus red supergiant
templates, nor on the method adopted. We measure a velocity dispersion of
sigma_los = 10.2+/-1.1 km/s for cluster 805 from our FFS. Our FLAMES+UVES
velocity dispersion measurement gives M_vir = (6.6+/-1.7)e5 M_sun, consistent
with previous results. This is a factor of ~3 greater than the cluster's
photometric mass, indicating a lack of virial equilibrium. However, based on
its effective star formation efficiency, the cluster is likely to virialise,
and may survive for a Hubble time, in the absence of external disruptive
forces; Conclusions: We find that reliable velocity dispersions can be
determined from FFS. The advantages of observing several clusters
simultaneously outweighs the difficulty of accurate galaxy background
subtraction, providing that the targets are chosen to provide sufficient S/N
ratios, and are much brighter than the galaxy background.

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The categories of this paper are: atom-ph
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th