Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relative abundance constraints from high-resolution optical transmission
  spectroscopy of WASP-121b, and a fast model-filtering technique for
  accelerating retrievals   High-resolution Doppler-resolved spectroscopy has presented new opportunities
for studying the atmospheres of exoplanets. While the 'classical'
cross-correlation approach has proven to be efficient at finding atmospheric
species, it is unable to perform direct atmospheric retrievals. Recent work has
shown that retrievals are possible using a direct likelihood evaluation or
likelihood 'mappings'. The unique aspect of high-resolution retrievals is that
the data-processing methods required to remove the stellar and telluric lines
also distort the underlying exoplanet's signal and therefore the forward model
must be pre-processed to match this filtering. This was the key remaining
limitation in our previously published framework. This paper directly addresses
this by introducing a simple and fast model-filtering technique that can
replicate the processing performed by algorithms such as SysRem and PCA. This
enables retrievals to be performed without having to perform expensive
injection and pre-processing steps for every model. We show that we can
reliably constrain quantitative measures of the atmosphere from transmission
spectra including the temperature-pressure profile, relative abundances,
planetary velocities and rotational broadening parameters. Finally, we
demonstrate our framework using UVES transmission spectroscopy of WASP-121b. We
constrain the temperature-pressure profile and relative abundances of Fe, Cr,
and V to be $\log_{10}(\chi_{\rm Fe}/\chi_{\rm Cr})$=1.66$\pm$0.28,
$\log_{10}(\chi_{\rm Fe}/\chi_{\rm V})$=3.78$\pm$0.29 and $\log_{10}(\chi_{\rm
Fe}/\chi_{\rm Mg})$=-1.26$\pm$0.60. The relative abundances are consistent with
solar values, with the exception of Fe/Mg, where the large Mg abundance is
probably explained by the escaping atmosphere of WASP-121b that is not
accounted for in our atmospheric model.

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The categories of this paper are: math
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
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The categories of this paper are: stat
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: physics