MINESweeper: Spectrophotometric Modeling of Stars in the Gaia Era. (arXiv:1907.07690v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Cargile_P/0/1/0/all/0/1">Phillip A. Cargile</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Conroy_C/0/1/0/all/0/1">Charlie Conroy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Johnson_B/0/1/0/all/0/1">Benjamin D. Johnson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ting_Y/0/1/0/all/0/1">Yuan-Sen Ting</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bonaca_A/0/1/0/all/0/1">Ana Bonaca</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dotter_A/0/1/0/all/0/1">Aaron Dotter</a>
We present MINESweeper, a tool to measure stellar parameters by jointly
fitting observed spectra and broadband photometry to model isochrones and
spectral libraries. This approach enables the measurement of spectrophotometric
distances, in addition to stellar parameters such as Teff, log(g), [Fe/H],
[alpha/Fe], and radial velocity. MINESweeper employs a Bayesian framework and
can easily incorporate a variety of priors, including Gaia parallaxes. Mock
data are fit in order to demonstrate how the precision of derived parameters
depends on evolutionary phase and SNR. We then fit a selection of data in order
to validate the model outputs. Fits to the benchmark stars Procyon, Arcturus,
and the Sun result in derived stellar parameters that are in excellent
agreement with the literature, except for the surface gravity of Arcturus,
where our value (1.35) is notably lower than the literature (1.66). We then fit
combined spectra and photometry of stars in the open and globular clusters M92,
M13, M3, M107, M71, and M67. Derived distances, [Fe/H], [alpha/Fe], and
log(g)-Teff, relations are in overall good agreement with literature values,
although there are trends between metallicity and log(g), within clusters that
point to systematic uncertainties at the ~0.1 dex level. Finally, we fit a
large sample of stars from the H3 Spectroscopic Survey in which high quality
Gaia parallaxes are also available. These stars are fit without the Gaia
parallaxes so that the geometric parallaxes can serve as an independent test of
the spectrophotometric distances. Comparison between the two reveals excellent
agreement within their formal uncertainties after accounting for the Gaia zero
point uncertainties.
We present MINESweeper, a tool to measure stellar parameters by jointly
fitting observed spectra and broadband photometry to model isochrones and
spectral libraries. This approach enables the measurement of spectrophotometric
distances, in addition to stellar parameters such as Teff, log(g), [Fe/H],
[alpha/Fe], and radial velocity. MINESweeper employs a Bayesian framework and
can easily incorporate a variety of priors, including Gaia parallaxes. Mock
data are fit in order to demonstrate how the precision of derived parameters
depends on evolutionary phase and SNR. We then fit a selection of data in order
to validate the model outputs. Fits to the benchmark stars Procyon, Arcturus,
and the Sun result in derived stellar parameters that are in excellent
agreement with the literature, except for the surface gravity of Arcturus,
where our value (1.35) is notably lower than the literature (1.66). We then fit
combined spectra and photometry of stars in the open and globular clusters M92,
M13, M3, M107, M71, and M67. Derived distances, [Fe/H], [alpha/Fe], and
log(g)-Teff, relations are in overall good agreement with literature values,
although there are trends between metallicity and log(g), within clusters that
point to systematic uncertainties at the ~0.1 dex level. Finally, we fit a
large sample of stars from the H3 Spectroscopic Survey in which high quality
Gaia parallaxes are also available. These stars are fit without the Gaia
parallaxes so that the geometric parallaxes can serve as an independent test of
the spectrophotometric distances. Comparison between the two reveals excellent
agreement within their formal uncertainties after accounting for the Gaia zero
point uncertainties.
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