Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The globular cluster system of NGC 1316. II - The extraordinary object
  SH2   SH2 has been described as an isolated HII-region, located about 6.5 arcmin
south of the nucleus of NGC 1316 (Fornax A), a merger remnant in the the
outskirts of the Fornax cluster of galaxies. We give a first, preliminary
description of the stellar content and environment of this remarkable object.
We used photometric data in the Washington system and HST photometry from the
Hubble Legacy Archive for a morphological description and preliminary aperture
photometry. Low-resolution spectroscopy provides radial velocities of the
brightest star cluster in SH2 and a nearby intermediate-age cluster. SH2 is not
a normal HII-region, ionized by very young stars. It contains a multitude of
star clusters with ages of approximately 0.1 Gyr. A ring-like morphology is
striking. SH2 seems to be connected to an intermediate-age massive globular
cluster with a similar radial velocity, which itself is the main object of a
group of fainter clusters. Metallicity estimates from emission lines remain
ambiguous. The present data do not yet allow firm conclusions about the nature
or origin of SH2. It might be a dwarf galaxy that has experienced a burst of
extremely clustered star formation. We may witness how globular clusters are
donated to a parent galaxy.

23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn