Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Possible evidence of p-modes in Cassini measurements of Saturn's gravity
  field   We analyze the range rate residual data from Cassini's gravity experiment
that cannot be explained with a static, zonally symmetric gravity field. In
this paper we reproduce the data using a simple forward model of gravity
perturbations from normal modes. To do this, we stack data from multiple flybys
to improve sensitivity. We find a partially degenerate set of normal mode
energy spectra which successfully reproduce the unknown gravity signal from
Cassini's flybys. Although there is no unique solution, we find that the models
most likely to fit the data are dominated by gravitational contributions from
p-modes between 500-700uHz. Because f-modes at lower frequencies have stronger
gravity signals for a given amplitude, this result would suggest strong
frequency dependence in normal mode excitation on Saturn. We predict peak
amplitudes for p-modes on the order of several kilometers, at least an order of
magnitude larger than the peak amplitudes inferred by Earth-based observations
of Jupiter. The large p-mode amplitudes we predict on Saturn, if they are
indeed present and steady state, would imply weak damping with a lower bound of
Q>1e7 for these modes, consistent with theoretical predictions.

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The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con