Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Volatile carbon locking and release in protoplanetary disks. A study of
  TW Hya and HD 100546   The composition of planetary solids and gases is largely rooted in the
processing of volatile elements in protoplanetary disks. To shed light on the
key processes, we carry out a comparative analysis of the gas-phase carbon
abundance in two systems with a similar age and disk mass, but different
central stars: HD 100546 and TW Hya. We combine our recent detections of
C$^{0}$ in these disks with observations of other carbon reservoirs (CO,
C$^{+}$, C$_{2}$H) and gas mass and warm gas tracers (HD, O$^{0}$), as well as
spatially resolved ALMA observations and the spectral energy distribution. The
disks are modelled with the DALI 2D physical-chemical code. Stellar abundances
for HD 100546 are derived from archival spectra. Upper limits on HD emission
from HD 100546 place an upper limit on the total disk mass of
$\leq0.1\,M_{\odot}$. The gas-phase carbon abundance in the atmosphere of this
warm Herbig disk is at most moderately depleted compared to the interstellar
medium, with [C]/[H]$_{\rm gas}=(0.1-1.5)\times 10^{-4}$. HD 100546 itself is a
$\lambda\,$Bo\"{o}tis star, with solar abundances of C and O but a strong
depletion of rock-forming elements. In the gas of the T Tauri disk TW Hya, both
C and O are strongly underabundant, with [C]/[H]$_{\rm gas}=(0.2-5.0)\times
10^{-6}$ and C/O${>}1$. We discuss evidence that the gas-phase C and O
abundances are high in the warm inner regions of both disks. Our analytical
model, including vertical mixing and a grain size distribution, reproduces the
observed [C]/[H]$_{\rm gas}$ in the outer disk of TW Hya and allows to make
predictions for other systems.

13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
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The categories of this paper are: nlin
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The categories of this paper are: acc-phys
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-ex
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The categories of this paper are: q-alg
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The categories of this paper are: hep-th
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The categories of this paper are: solv-int