Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mid-infrared spectroscopy of SVS13: Silicates, quartz and SiC in a
  protoplanetary disc   We present $N$-band (8$-$13 $\mu$m) spectroscopic observations of the
low-mass, embedded pre-main-sequence close binary system SVS13. Absorption
features are clearly detected which are attributable to amorphous silicates,
crystalline forsterite, crystalline enstatite and annealed SiO$_{2}$. Most
intriguingly, a major component of the dust in the envelope or disc around
SVS13 appears to be SiC, required to model adequately both the total intensity
and polarisation spectra. Silicon carbide is a species previously detected only
in the spectra of C-rich evolved star atmospheres, wherein it is a dust
condensate. It has not been unambiguously identified in the interstellar
medium, and never before in a molecular cloud, let alone in close proximity to
a forming star. Yet pre-Solar grains of SiC have been identified in meteorites,
possibly suggesting an interesting parallel between SVS13 and our own
Solar-System evolution. The uniqueness of the spectrum suggests that we are
either catching SVS13 in a short-lived evolutionary phase and/or that there is
something special about SVS13 itself that makes it rare amongst young stars. We
speculate on the physical origin of the respective dust species and why they
are all simultaneously present toward SVS13. Two scenarios are presented: a
disc-instability-induced fragmentation, with subsequent localised heating and
orbital evolution firstly annealing initially amorphous silicates and then
dispersing their crystalline products throughout a circumstellar disc; and a
newly discovered shock-heating mechanism at the interface between the
circumstellar and circumbinary discs providing the crystallisation process. One
or both of these mechanisms acting on carbon-rich grain material can also
feasibly produce the SiC signature.

4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics