Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tentative Evidence for Water Vapor in the Atmosphere of the Neptune-Size
  Exoplanet HD 106315 c   We present a transmission spectrum for the Neptune-size exoplanet HD 106315 c
from optical to infrared wavelengths based on transit observations from the
Hubble Space Telescope/Wide Field Camera 3, K2, and Spitzer. The spectrum shows
tentative evidence for a water absorption feature in the $1.1 - 1.7\mu$m
wavelength range with a small amplitude of 30 ppm (corresponding to just $0.8
\pm 0.04$ atmospheric scale heights). Based on an atmospheric retrieval
analysis, the presence of water vapor is tentatively favored with a Bayes
factor of 1.7 - 2.6 (depending on prior assumptions). The spectrum is most
consistent with either enhanced metallicity, high altitude condensates, or
both. Cloud-free solar composition atmospheres are ruled out at $>5\sigma$
confidence. We compare the spectrum to grids of cloudy and hazy forward models
and find that the spectrum is fit well by models with moderate cloud lofting or
haze formation efficiency, over a wide range of metallicities ($1 - 100\times$
solar). We combine the constraints on the envelope composition with an interior
structure model and estimate that the core mass fraction is $\gtrsim0.3$. With
a bulk composition reminiscent of that of Neptune and an orbital distance of
0.15 AU, HD 106315 c hints that planets may form out of broadly similar
material and arrive at vastly different orbits later in their evolution.

27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs