Bibcode
Schultheis, M.; Zasowski, G.; Allende Prieto, C.; Anders, F.; Beaton, R. L.; Beers, T. C.; Bizyaev, D.; Chiappini, C.; Frinchaboy, P. M.; García Pérez, A. E.; Ge, J.; Hearty, F.; Holtzman, J.; Majewski, S. R.; Muna, D.; Nidever, D.; Shetrone, M.; Schneider, D. P.
Referencia bibliográfica
The Astronomical Journal, Volume 148, Issue 1, article id. 24, 10 pp. (2014).
Fecha de publicación:
7
2014
Número de citas
45
Número de citas referidas
39
Descripción
Galactic interstellar extinction maps are powerful and necessary tools
for Milky Way structure and stellar population analyses, particularly
toward the heavily reddened bulge and in the midplane. However, due to
the difficulty of obtaining reliable extinction measures and distances
for a large number of stars that are independent of these maps, tests of
their accuracy and systematics have been limited. Our goal is to assess
a variety of photometric stellar extinction estimates, including both
two-dimensional and three-dimensional extinction maps, using independent
extinction measures based on a large spectroscopic sample of stars
toward the Milky Way bulge. We employ stellar atmospheric parameters
derived from high-resolution H-band Apache Point Observatory Galactic
Evolution Experiment (APOGEE) spectra, combined with theoretical stellar
isochrones, to calculate line-of-sight extinction and distances for a
sample of more than 2400 giants toward the Milky Way bulge. We compare
these extinction values to those predicted by individual near-IR and
near+mid-IR stellar colors, two-dimensional bulge extinction maps, and
three-dimensional extinction maps. The long baseline, near+mid-IR
stellar colors are, on average, the most accurate predictors of the
APOGEE extinction estimates, and the two-dimensional and
three-dimensional extinction maps derived from different stellar
populations along different sightlines show varying degrees of
reliability. We present the results of all of the comparisons and
discuss reasons for the observed discrepancies. We also demonstrate how
the particular stellar atmospheric models adopted can have a strong
impact on this type of analysis, and discuss related caveats.
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