J/AJ/167/208 The APO-K2 Catalog. II. Red giants stellar ages (Warfield+, 2024)
The APO-K2 Catalog.
II. Accurate Stellar Ages for Red Giant Branch Stars across the Milky Way.
Warfield J.T., Zinn J.C., Schonhut-Stasik J., Johnson J.W.,
Pinsonneault M.H., Johnson J.A., Stello D., Beaton R.L., Elsworth Y.,
Garcia R.A., Mathur S., Mosser B., Serenelli A., Tayar J.
<Astron. J., 167, 208 (2024)>
=2024AJ....167..208W 2024AJ....167..208W
ADC_Keywords: Milky Way; Stars, giant; Stars, ages; Abundances, [Fe/H];
Stars, masses; Stars, diameters; Infrared
Keywords: Stellar ages ; Asteroseismology ; Stellar abundances ; Milky
Way evolution ; Milky Way formation ; Galaxy stellar content ;
Red giant stars ; Stellar evolutionary models
Abstract:
We present stellar age determinations for 4661 red giant branch stars
in the APO-K2 catalog, derived using mass estimates from K2
asteroseismology from the K2 Galactic Archaeology Program and
elemental abundances from the Apache Point Galactic Evolution
Experiment survey. Our sample includes 17 of the 19 fields observed by
K2, making it one of the most comprehensive catalogs of accurate
stellar ages across the Galaxy in terms of the wide range of
populations spanned by its stars, enabling rigorous tests of Galactic
chemical evolution models. Taking into account the selection functions
of the K2 sample, the data appear to support the age-chemistry
morphology of stellar populations predicted by both inside-out and
late-burst scenarios. We also investigate trends in age versus stellar
chemistry and Galactic position, which are consistent with previous
findings. Comparisons against APOKASC-3 asteroseismic ages show
agreement to within ∼3%. We also discuss offsets between our ages and
spectroscopic ages. Finally, we note that ignoring the effects of
α-enhancement on stellar opacity (either directly or with the
Salaris metallicity correction) results in an ∼10% offset in age
estimates for the most α-enhanced stars, which is an important
consideration for continued tests of Galactic models with this and
other asteroseismic age samples.
Description:
APOGEE DR17 is a part of the final data release of the Sloan Digital
Sky Survey Phase IV (SDSS-IV) and provides high-resolution
near-infrared spectra (using twin, R∼22500 H-band spectrographs).
Spectra were collected using the 2.5m Sloan Foundation Telescope at
the Apache Point Observatory in New Mexico, USA (APOGEE-North), from
2011 to 2020 and the 2.5m du Pont Telescope at Las Campanas
Observatory in Chile (APOGEE-South) from 2017 to 2020.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 245 4661 APO-K2 RGB sample
table2.dat 223 3209 Re-calibrated APOKASC-2 RGB sample
table3.dat 239 1912 APO-K2 RC sample
table4.dat 226 230 APO-K2 sample with [Fe/H]<(-1)
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
III/286 : APOGEE-2 DR17 final allStar catalog (Abdurro'uf+, 2022)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/AJ/112/359 : Galaxies in the Hubble Deep Field (van den Bergh+ 1996)
J/A+A/410/527 : Abundances in the Galactic disk (Bensby+, 2003)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
J/ApJ/746/16 : Modelling the convection zone (van Saders+, 2012)
J/MNRAS/456/3655 : Masses and ages of red giants (Martig+, 2016)
J/A+A/597/A30 : Seismology & spectroscopy CoRoGEE red giants (Anders+, 2017)
J/ApJ/835/83 : K2 GAP data release. I. Campaign 1 (Stello+, 2017)
J/MNRAS/476/3233 : 14983 Kepler red giants (Hon+, 2018)
J/ApJS/239/32 : APOKASC-2 cat of Kepler evolved stars (Pinsonneault+, 2018)
J/MNRAS/475/5487 : Stellar properties of KIC stars (Silva Aguirre+, 2018)
J/MNRAS/489/4641 : APOKASC Evolutionary state red-giant stars (Elsworth+, 2019)
J/MNRAS/489/176 : Dynamical heating across Milky Way disc (Mackereth+, 2019)
J/ApJ/878/21 : Vertical motions APOGEE & Gaia red clump stars (Ting+, 2019)
J/A+A/627/A173 : Abundances for 4 metal-poor stars (Valentini+, 2019)
J/ApJS/251/23 : K2 GAP DR2; campaigns 4, 6 & 7 (Zinn+, 2020)
J/A+A/645/A85 : Age dissection of the Milky Way discs (Miglio+, 2021)
J/AJ/161/100 : Ages & alpha-abundances population in K2 (Warfield+, 2021)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- EPIC Ecliptic Plane Input Catalog (EPIC)
identifier
11- 28 A18 --- APOGEE APOGEE Identifier
30- 48 I19 --- GaiaEDR3 Gaia EDR3 identifier [source_id]
50- 57 F8.4 deg RAdeg [8/360] Right Ascension (J2000)
59- 66 F8.4 deg DEdeg [-31/28] Declination (J2000)
68- 74 F7.3 deg GLON [0/360] Galactic longitude
76- 82 F7.3 deg GLAT [-67/66] Galactic latitude
84- 89 A6 kpc Rkpc Galactocentric R position
91- 96 A6 kpc Zkpc Galactocentric Z position
98-101 I4 K Teff [3726/5374] APOGEE calibrated effective
temperature
103-106 I4 K Teff-u [3643/5326] APOGEE uncalibrated effective
temperature
108-110 I3 K e_Teff [4/161] Uncertainty in Teff
112-115 F4.2 [cm.s-2] logg [0.9/4.61] APOGEE calibrated log surface
gravity
117-120 F4.2 [cm.s-2] logg-u [1.01/4.46] APOGEE uncalibrated log
surface gravity
122-125 F4.2 [cm.s-2] e_logg [0.02/0.33] Uncertainty in logg
127-132 F6.3 [Sun] [Fe/H] [-0.999/0.419] APOGEE log Iron abundance
relative to Hydrogen
134-138 F5.3 [Sun] e_[Fe/H] [0.006/0.043] Uncertainty in [Fe/H]
140-144 F5.3 [Sun] [a/M] [0.0/0.387] APOGEE log
α-element/Metal abundance ratio
146-150 F5.3 [Sun] e_[a/M] [0.003/0.509] Uncertainty in [a/M]
152-157 A6 [Sun] [O/Fe] APOGEE log Oxygen abundance relative
to Iron
159-163 A5 [Sun] e_[O/Fe] Uncertainty in [O/Fe]
165-166 I2 --- aFlag [-1/1] The α flag (1)
168-171 F4.2 Msun Mstar [0.6/2.59] Stellar mass, solar units (2)
173-176 F4.2 Msun e_Mstar [0.0/1.98] Uncertainty in Mstar
178-182 F5.2 Rsun Rstar [3.75/31.41] Stellar radius (2)
184-187 F4.2 Rsun e_Rstar [0.01/9.39] Uncertainty in Mstar
189-192 F4.2 [cm.s-2] logg-seis [1.59/3.32] Stellar log surface gravity
(2)
194-197 F4.2 [cm.s-2] e_logg-seis [0.0/0.06] Uncertainty in logg-seis
199-203 F5.1 uHz numax [5.1/257.0] frequency of maximum
acoustic power
205-207 F3.1 uHz e_numax [0.0/2.3] Uncertainty in numax
209-213 F5.2 uHz deltanu [1.0/18.04] Large frequency-spacing
215-218 F4.2 uHz e_deltanu [0.0/0.32] Uncertainty in deltanu
220-223 F4.1 Gyr Age [0.5/74.2] Age
225-228 F4.1 Gyr e_Age [0.1/64.4] Lower uncertainty in Age
230-234 F5.1 Gyr E_Age [0.1/490.8] Upper uncertainty in Age
236-239 F4.1 Gyr Age-mode [0.3/30.0] Modal Age
241-245 A5 --- SFW Galaxia selection function weighting (3)
--------------------------------------------------------------------------------
Note (1): The alpha flag as follows:
-1 = unclassified stars;
0 = α-poor stars;
1 = α-rich stars.
Note (2): Mass, Radius and logg-seis derived from asteroseismic
scaling relations calibrated to Gaia DR2 radius scale; see Zinn+,
2022, J/ApJ/926/191 and Appendix A.3
Note (3): The weighting for that star given by the Galaxia selection
function, and have been normalized so that the maximum weight is 100.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 27 A18 --- APOGEE APOGEE Identifier
29- 47 I19 --- GaiaEDR3 Gaia EDR3 identifier [source_id]
49- 56 F8.4 deg RAdeg [280/302] Right Ascension (J2000)
58- 64 F7.4 deg DEdeg [36/53] Declination (J2000)
66- 71 F6.3 deg GLON [68/85] Galactic longitude
73- 78 F6.3 deg GLAT [5/22] Galactic latitude
80- 85 F6.3 kpc Rkpc [7.549/11.464] Galactocentric R position
87- 91 F5.3 kpc Zkpc [0.058/2.619] Galactocentric Z position
93- 96 I4 K Teff [3854/5140] APOGEE calibrated effective
temperature
98-101 I4 K Teff-u [3773/5096] APOGEE uncalibrated effective
temperature
103-104 I2 K e_Teff [4/22] Uncertainty in Teff
106-109 F4.2 [cm.s-2] logg [1.17/3.42] APOGEE calibrated log surface
gravity
111-114 F4.2 [cm.s-2] logg-u [1.26/3.48] APOGEE uncalibrated log
surface gravity
116-119 F4.2 [cm.s-2] e_logg [0.02/0.05] Uncertainty in logg
121-126 F6.3 [Sun] [Fe/H] [-0.994/0.401] APOGEE log Iron abundance
relative to Hydrogen
128-132 F5.3 [Sun] e_[Fe/H] [0.006/0.017] Uncertainty in [Fe/H]
134-138 F5.3 [Sun] [a/M] [0.0/0.324] APOGEE log α-element/
Metal abundance ratio
140-144 F5.3 [Sun] e_[a/M] [0.003/0.179] Uncertainty in [a/M]
146-147 I2 --- aFlag [-1/1] The α flag (1)
149-152 F4.2 Msun Mstar [0.61/2.19] Stellar mass, solar units (2)
154-157 F4.2 Msun e_Mstar [0.03/0.84] Uncertainty in Mstar
159-163 F5.2 Rsun Rstar [3.6/53.9] Stellar radius, solar units (2)
165-168 F4.2 Rsun e_Rstar [0.05/3.71] Uncertainty in Mstar
170-173 F4.2 [cm.s-2] logg-seis [1.17/3.31] Stellar log surface gravity
(2)
175-180 F6.2 [cm.s-2] e_logg-seis [54.39/212.12] Uncertainty in logg-seis
182-186 F5.1 uHz numax [2.0/249.8] frequency of maximum acoustic
power
188-191 F4.1 uHz e_numax [0.0/11.1] Uncertainty in numax
193-197 F5.2 uHz deltanu [0.45/18.78] Large frequency-spacing
199-202 F4.2 uHz e_deltanu [0.0/0.86] Uncertainty in deltanu
204-207 F4.1 Gyr Age [0.6/60.6] Age
209-212 F4.1 Gyr e_Age [0.1/38.7] Lower uncertainty in Age
214-218 F5.1 Gyr E_Age [0.1/149.0] Upper uncertainty in Age
220-223 F4.1 Gyr Age-mode [0.5/30.0] Modal Age
--------------------------------------------------------------------------------
Note (1): The alpha flag as follows:
-1 = unclassified stars;
0 = α-poor stars;
1 = α-rich stars.
Note (2): Mass, Radius and logg-seis derived from asteroseismic
scaling relations calibrated to Gaia DR2 radius scale; see Zinn+,
2022, J/ApJ/926/191 and Appendix A.3
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- EPIC Ecliptic Plane Input Catalog (EPIC)
identifier
11- 28 A18 --- APOGEE APOGEE Identifier
30- 48 I19 --- GaiaEDR3 Gaia EDR3 identifier [source_id]
50- 57 F8.4 deg RAdeg [9/360] Right Ascension (J2000)
59- 66 F8.4 deg DEdeg [-31/28] Declination (J2000)
68- 74 F7.3 deg GLON [0/360] Galactic longitude
76- 82 F7.3 deg GLAT [-67/66] Galactic latitude
84- 89 A6 kpc Rkpc Galactocentric R position
91- 96 A6 kpc Zkpc Galactocentric Z position
98-101 I4 K Teff [3726/5374] APOGEE calibrated effective
temperature
103-106 I4 K Teff-u [3643/5326] APOGEE uncalibrated effective
temperature
108-110 I3 K e_Teff [4/161] Uncertainty in Teff
112-115 F4.2 [cm.s-2] logg [0.9/3.27] APOGEE calibrated log surface
gravity
117-120 F4.2 [cm.s-2] logg-u [1.01/3.28] APOGEE uncalibrated log
surface gravity
122-125 F4.2 [cm.s-2] e_logg [0.02/0.33] Uncertainty in logg
127-132 F6.3 [Sun] [Fe/H] [-0.999/0.505] APOGEE log Iron abundance
relative to Hydrogen
134-138 F5.3 [Sun] e_[Fe/H] [0.006/0.039] Uncertainty in [Fe/H]
140-144 F5.3 [Sun] [a/M] [0.0/0.387] APOGEE log
α-element/Metal abundance ratio
146-150 F5.3 [Sun] e_[a/M] [0.003/0.284] Uncertainty in [a/M]
152-157 F6.3 [Sun] [O/Fe] [-0.531/0.813] APOGEE log Oxygen
abundance relative to Iron
159-163 F5.3 [Sun] e_[O/Fe] [0.007/0.129] Uncertainty in [O/Fe]
165-166 I2 --- aFlag [-1/1] The α flag (1)
168-171 F4.2 Msun Mstar [0.6/2.59] Stellar mass, solar units (2)
173-176 F4.2 Msun e_Mstar [0.01/1.98] Uncertainty in Mstar
178-182 F5.2 Rsun Rstar [5.35/31.41] Stellar radius, solar units
(2)
184-187 F4.2 Rsun e_Rstar [0.04/9.39] Uncertainty in Mstar
189-192 F4.2 [cm.s-2] logg-seis [1.59/3.12] Stellar log surface gravity
(2)
194-197 F4.2 [cm.s-2] e_logg-seis [0.0/0.06] Uncertainty in logg-seis
199-203 F5.1 uHz numax [5.1/155.8] frequency of maximum acoustic
power
205-207 F3.1 uHz e_numax [0.0/2.0] Uncertainty in numax
209-213 F5.2 uHz deltanu [1.0/12.74] Large frequency-spacing
215-218 F4.2 uHz e_deltanu [0.0/0.32] Uncertainty in deltanu
220-223 F4.1 Gyr Age [0.4/77.6] Age
225-228 F4.1 Gyr e_Age [0.1/68.6] Lower uncertainty in Age
230-234 F5.1 Gyr E_Age [0.1/591.1] Upper uncertainty in Age
236-239 F4.1 Gyr Age-mode [0.3/30.0] Modal Age
--------------------------------------------------------------------------------
Note (1): The alpha flag as follows:
-1 = unclassified stars;
0 = α-poor stars;
1 = α-rich stars.
Note (2): Mass, Radius and logg-seis derived from asteroseismic
scaling relations calibrated to Gaia DR2 radius scale; see Zinn+,
2022, J/ApJ/926/191 and Appendix A.3
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- EPIC Ecliptic Plane Input Catalog (EPIC)
identifier
11- 28 A18 --- APOGEE APOGEE Identifier
30- 48 I19 --- GaiaEDR3 Gaia EDR3 identifier [source_id]
50- 57 F8.4 deg RAdeg [9/357] Right Ascension (J2000)
59- 66 F8.4 deg DEdeg [-30/25] Declination (J2000)
68- 74 F7.3 deg GLON [0/360] Galactic longitude
76- 82 F7.3 deg GLAT [-67/65] Galactic latitude
84- 89 F6.3 kpc Rkpc [1.668/14.783] Galactocentric R position
91- 96 F6.3 kpc Zkpc [-6.35/9.91] Galactocentric Z position
98-101 I4 K Teff-u [4382/5741] APOGEE uncalibrated effective
temperature
103-105 I3 K e_Teff-u [10/706] Uncertainty in Teff
107-110 F4.2 [cm.s-2] logg-u [1.2/3.79] APOGEE uncalibrated log surface
gravity
112-115 F4.2 [cm.s-2] e_logg-u [0.03/1.14] Uncertainty in logg
117-122 F6.3 [Sun] [Fe/H] [-1.998/-1.0] APOGEE log Iron abundance
relative to Hydrogen
124-128 F5.3 [Sun] e_[Fe/H] [0.009/0.099] Uncertainty in
130-134 F5.3 [Sun] [a/M] [0.054/0.385] APOGEE log α-element/
Metal abundance ratio
136-140 F5.3 [Sun] e_[a/M] [0.011/0.271] Uncertainty in
142-147 A6 [Sun] [O/Fe] APOGEE log Oxygen abundance relative
to Iron
149-153 A5 [Sun] e_[O/Fe] Uncertainty in [O/Fe]
155-158 F4.2 Msun Mstar [0.6/2.25] Stellar mass, solar units (1)
160-163 F4.2 Msun e_Mstar [0.02/0.77] Uncertainty in Mstar
165-169 F5.2 Rsun Rstar [4.4/25.25] Stellar radius (1)
171-174 F4.2 Rsun e_Rstar [0.05/3.91] Uncertainty in Mstar
176-179 F4.2 [cm.s-2] logg-seis [1.71/3.1] Stellar log surface gravity (1)
181-184 F4.2 [cm.s-2] e_logg-seis [0.0/0.04] Uncertainty in logg-seis
186-190 F5.1 uHz numax [6.6/152.9] frequency of maximum acoustic
power
192-194 F3.1 uHz e_numax [0.0/1.8] Uncertainty in numax
196-200 F5.2 uHz deltanu [1.2/13.87] Large frequency-spacing
202-205 F4.2 uHz e_deltanu [0.0/0.23] Uncertainty in deltanu
207-210 F4.1 Gyr Age [0.5/37.6] Age
212-215 F4.1 Gyr e_Age [0.1/21.4] Lower uncertainty in Age
217-221 F5.1 Gyr E_Age [0.1/127.2] Upper uncertainty in Age
223-226 F4.1 Gyr Age-mode [0.4/30.0] Modal Age
--------------------------------------------------------------------------------
Note (1): Mass, Radius and logg-seis derived from asteroseismic
scaling relations calibrated to Gaia DR2 radius scale; see Zinn+,
2022, J/ApJ/926/191 and Appendix A.3
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Schonhut-Stasik et al. Paper I : 2024AJ....167...50S 2024AJ....167...50S
(End) Prepared by [AAS], Coralie Fix [CDS], 10-Jun-2024