Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: VLT/ISAAC H-band spectroscopy of embedded massive YSOs   We have performed intermediate resolution (R = 5000), high signal-to-noise
H-band spectroscopy of a small, initial sample of three massive embedded young
stellar objects (YSOs), using VLT/ISAAC. The sample has been selected from
sources characterised in previous literature as being likely of OB spectral
type, to be unambiguously associated with bright (H < 14) single point sources
in the 2MASS database, and to have no optical counterparts. Of the targets
observed, one object shows a ~B3 spectrum, similar to a main sequence object of
the same spectral type. A second object exhibits weak HeI and H emission,
indicating an early-type source: we detect HeII absorption, which supports a
previous indirect derivation of the spectral type as mid-O. The third object
does not show absorption lines, so no spectral type can de derived. It does,
however, exhibit a rich spectrum of strong, broad emission lines and is likely
to be surrounded by dense circumstellar material and at a very early
evolutionary stage. Our results from this very small sample are in agreement
with those of Kaper et al. (2002), who also find spectra similar to optically
visible main sequence stars, together with emission line objects representing a
very early evolutionary phase, in their much larger sample of K-band spectra.

24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess