Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Arid or Cloudy: Characterizing the Atmosphere of the super-Earth 55
  Cancri e using High-Resolution Spectroscopy   The nearby super-Earth 55 Cnc e orbits a bright (V = 5.95 mag) star with a
period of ~ 18 hours and a mass of ~ 8 Earth masses. Its atmosphere may be
water-rich and have a large scale-height, though attempts to characterize it
have yielded ambiguous results. Here we present a sensitive search for water
and TiO in its atmosphere at high spectral resolution using the Gemini North
telescope and the GRACES spectrograph. We combine observations with previous
observations from Subaru and CFHT, improving the constraints on the presence of
water vapor. We adopt parametric models with an updated planet radius based on
recent measurements, and use a cross-correlation technique to maximize
sensitivity. Our results are consistent with atmospheres that are cloudy or
contain minimal amounts of water and TiO. Using these parametric models, we
rule out a water-rich atmosphere (VMR >= 0.1%) with a mean molecular weight of
<= 15 g/mol at a 3 sigma confidence level, improving on the previous limit by a
significant margin. For TiO, we rule out a mean molecular weight of <= 5 g/mol
with a 3 sigma confidence level for a VMR greater than 10^-8; for a VMR of
greater than 10^-7, the limit rises to a mean molecular weight of <= 10 g/mol.
We can rule out low mean-molecular-weight chemical equilibrium models both
including and excluding TiO/VO at very high confidence levels (> 10 sigma).
Overall, our results are consistent with an atmosphere with a high mean
molecular weight and/or clouds, or no atmosphere.

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The categories of this paper are: physics
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ex
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The categories of this paper are: econ
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: hep-th
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The categories of this paper are: bayes-an
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The categories of this paper are: cond-mat
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc