Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Spitzer Gould Belt Survey of Large Nearby Interstellar Clouds:
  Discovery of a Dense Embedded Cluster in the Serpens-Aquila Rift   We report the discovery of a nearby, embedded cluster of young stellar
objects, associated filamentary infrared dark cloud, and 4.5 micron shock
emission knots from outflows detected in Spitzer/IRAC mid-infrared imaging of
the Serpens-Aquila Rift obtained as part of the Spitzer Gould Belt Legacy
Survey. We also present radial velocity measurements of the region from
molecular line observations obtained with the Submillimeter Array (SMA) that
suggest the cluster is co-moving with the Serpens Main embedded cluster 3
degrees to the north. We therefore assign it the same distance, 260 pc. The
core of the new cluster, which we call Serpens South, is composed of an
unusually large fraction of protostars (77%) at high mean surface density (>430
pc^-2) and short median nearest neighbor spacing (3700 AU). We perform basic
cluster structure characterization using nearest neighbor surface density
mapping of the YSOs and compare our findings to other known clusters with
equivalent analyses available in the literature.

23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an