Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The expected performance of stellar parametrization with Gaia
  spectrophotometry   Gaia will obtain astrometry and spectrophotometry for essentially all sources
in the sky down to a broad band magnitude limit of G=20, an expected yield of
10^9 stars. Its main scientific objective is to reveal the formation and
evolution of our Galaxy through chemo-dynamical analysis. In addition to
inferring positions, parallaxes and proper motions from the astrometry, we must
also infer the astrophysical parameters of the stars from the
spectrophotometry, the BP/RP spectrum. Here we investigate the performance of
three different algorithms (SVM, ILIUM, Aeneas) for estimating the effective
temperature, line-of-sight interstellar extinction, metallicity and surface
gravity of A-M stars over a wide range of these parameters and over the full
magnitude range Gaia will observe (G=6-20mag). One of the algorithms, Aeneas,
infers the posterior probability density function over all parameters, and can
optionally take into account the parallax and the Hertzsprung-Russell diagram
to improve the estimates. For all algorithms the accuracy of estimation depends
on G and on the value of the parameters themselves, so a broad summary of
performance is only approximate. For stars at G=15 with less than two
magnitudes extinction, we expect to be able to estimate Teff to within 1%, logg
to 0.1-0.2dex, and [Fe/H] (for FGKM stars) to 0.1-0.2dex, just using the BP/RP
spectrum (mean absolute error statistics are quoted). Performance degrades at
larger extinctions, but not always by a large amount. Extinction can be
estimated to an accuracy of 0.05-0.2mag for stars across the full parameter
range with a priori unknown extinction between 0 and 10mag. Performance
degrades at fainter magnitudes, but even at G=19 we can estimate logg to better
than 0.2dex for all spectral types, and [Fe/H] to within 0.35dex for FGKM
stars, for extinctions below 1mag.

20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex