TY - JOUR
T1 - Chemical Cartography with APOGEE
T2 - Mapping Disk Populations with a 2-process Model and Residual Abundances
AU - Weinberg, David H.
AU - Holtzman, Jon A.
AU - Johnson, Jennifer A.
AU - Hayes, Christian
AU - Hasselquist, Sten
AU - Shetrone, Matthew
AU - Ting, Yuan Sen
AU - Beaton, Rachael L.
AU - Beers, Timothy C.
AU - Bird, Jonathan C.
AU - Bizyaev, Dmitry
AU - Blanton, Michael R.
AU - Cunha, Katia
AU - Fernández-Trincado, José G.
AU - Frinchaboy, Peter M.
AU - García-Hernández, D. A.
AU - Griffith, Emily
AU - Johnson, James W.
AU - Jönsson, Henrik
AU - Lane, Richard R.
AU - Leung, Henry W.
AU - Mackereth, J. Ted
AU - Majewski, Steven R.
AU - Mészáros, Szabolcs
AU - Nitschelm, Christian
AU - Pan, Kaike
AU - Schiavon, Ricardo P.
AU - Schneider, Donald P.
AU - Schultheis, Mathias
AU - Smith, Verne
AU - Sobeck, Jennifer S.
AU - Stassun, Keivan G.
AU - Stringfellow, Guy S.
AU - Vincenzo, Fiorenzo
AU - Wilson, John C.
AU - Zasowski, Gail
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022
Y1 - 2022
N2 - We apply a novel statistical analysis to measurements of 16 elemental abundances in 34,410 Milky Way disk stars from the final data release (DR17) of APOGEE-2. Building on recent work, we fit median abundance ratio trends [X/Mg] versus [Mg/H] with a 2-process model, which decomposes abundance patterns into a "prompt"component tracing core-collapse supernovae and a "delayed"component tracing Type Ia supernovae. For each sample star, we fit the amplitudes of these two components, then compute the residuals δ[X/H] from this two-parameter fit. The rms residuals range from ∼0.01-0.03 dex for the most precisely measured APOGEE abundances to ∼0.1 dex for Na, V, and Ce. The correlations of residuals reveal a complex underlying structure, including a correlated element group comprised of Ca, Na, Al, K, Cr, and Ce and a separate group comprised of Ni, V, Mn, and Co. Selecting stars poorly fit by the 2-process model reveals a rich variety of physical outliers and sometimes subtle measurement errors. Residual abundances allow for the comparison of populations controlled for differences in metallicity and [α/Fe]. Relative to the main disk (R = 3-13 kpc), we find nearly identical abundance patterns in the outer disk (R = 15-17 kpc), 0.05-0.2 dex depressions of multiple elements in LMC and Gaia Sausage/Enceladus stars, and wild deviations (0.4-1 dex) of multiple elements in ω Cen. The residual abundance analysis opens new opportunities for discovering chemically distinctive stars and stellar populations, for empirically constraining nucleosynthetic yields, and for testing chemical evolution models that include stochasticity in the production and redistribution of elements.
AB - We apply a novel statistical analysis to measurements of 16 elemental abundances in 34,410 Milky Way disk stars from the final data release (DR17) of APOGEE-2. Building on recent work, we fit median abundance ratio trends [X/Mg] versus [Mg/H] with a 2-process model, which decomposes abundance patterns into a "prompt"component tracing core-collapse supernovae and a "delayed"component tracing Type Ia supernovae. For each sample star, we fit the amplitudes of these two components, then compute the residuals δ[X/H] from this two-parameter fit. The rms residuals range from ∼0.01-0.03 dex for the most precisely measured APOGEE abundances to ∼0.1 dex for Na, V, and Ce. The correlations of residuals reveal a complex underlying structure, including a correlated element group comprised of Ca, Na, Al, K, Cr, and Ce and a separate group comprised of Ni, V, Mn, and Co. Selecting stars poorly fit by the 2-process model reveals a rich variety of physical outliers and sometimes subtle measurement errors. Residual abundances allow for the comparison of populations controlled for differences in metallicity and [α/Fe]. Relative to the main disk (R = 3-13 kpc), we find nearly identical abundance patterns in the outer disk (R = 15-17 kpc), 0.05-0.2 dex depressions of multiple elements in LMC and Gaia Sausage/Enceladus stars, and wild deviations (0.4-1 dex) of multiple elements in ω Cen. The residual abundance analysis opens new opportunities for discovering chemically distinctive stars and stellar populations, for empirically constraining nucleosynthetic yields, and for testing chemical evolution models that include stochasticity in the production and redistribution of elements.
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U2 - 10.3847/1538-4365/ac6028
DO - 10.3847/1538-4365/ac6028
M3 - Article
AN - SCOPUS:85133549275
SN - 0067-0049
VL - 260
JO - Astrophysical Journal, Supplement Series
JF - Astrophysical Journal, Supplement Series
IS - 2
M1 - 32
ER -