J/ApJS/251/23 K2 GAP DR2: campaigns 4, 6 & 7 (Zinn+, 2020)
The K2 Galactic Archaeology Program Data Release 2: asteroseismic results from
campaigns 4, 6, and 7.
Zinn J.C., Stello D., Elsworth Y., Garcia R.A., Kallinger T., Mathur S.,
Mosser B., Bugnet L., Jones C., Hon M., Sharma S., Schonrich R.,
Warfield J.T., Luger R., Pinsonneault M.H., Johnson J.A., Huber D.,
Silva Aguirre V., Chaplin W.J., Davies G.R., Miglio A.
<Astrophys. J. Suppl. Ser., 251, 23 (2020)>
=2020ApJS..251...23Z 2020ApJS..251...23Z
ADC_Keywords: Asteroseismology; Stars, giant; Infrared sources
Keywords: Asteroseismology ; Catalogs ; Stellar radii ; Stellar masses ;
Red giant clump ; Red giant branch
Abstract:
Studies of Galactic structure and evolution have benefited enormously
from Gaia kinematic information, though additional, intrinsic stellar
parameters like age are required to best constrain Galactic models.
Asteroseismology is the most precise method of providing such
information for field star populations en masse, but existing samples
for the most part have been limited to a few narrow fields of view by
the CoRoT and Kepler missions. In an effort to provide
well-characterized stellar parameters across a wide range in Galactic
position, we present the second data release of red giant
asteroseismic parameters for the K2 Galactic Archaeology Program (GAP).
We provide νmax and Δν based on six independent pipeline
analyses; first-ascent red giant branch (RGB) and red clump (RC)
evolutionary state classifications from machine learning; and
ready-to-use radius and mass coefficients, κR and κM,
which, when appropriately multiplied by a solar-scaled effective
temperature factor, yield physical stellar radii and masses. In total,
we report 4395 radius and mass coefficients, with typical
uncertainties of 3.3% (stat.) ±1% (syst.) for κR and
7.7% (stat.) ±2% (syst.) for κM among RGB stars, and
5.0% (stat.) ±1% (syst.) for κR and
10.5% (stat.) ±2% (syst.) for κM among RC stars. We verify
that the sample is nearly complete- except for a dearth of stars with
νmax≲10-20µHz-by comparing to Galactic models and visual
inspection. Our asteroseismic radii agree with radii derived from Gaia
Data Release 2 parallaxes to within 2.2%±0.3% for RGB stars and
2.0%±0.6% for RC stars.
Description:
In the context of the Galactic Archaeology Program (GAP;
Stello+ 2015ApJ...809L...3S 2015ApJ...809L...3S), analyses of the Kepler K2 campaigns
presented here were prioritized due to their coverage of the sky:
the Galactic center (C7; 2015 Oct-Dec), the Galactic anticenter (C4;
2015 Feb-Apr), and out of the Galactic plane (C6; 2015 Jul-Sep).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 194 19032 *Raw asteroseismic νmax and Δν values
for K2 Galactic Archaeology Program (GAP) DR2
for each pipeline, with evolutionary states
table4.dat 171 4618 *Derived asteroseismic νmax and Δν
values for K2 GAP DR2
table6.dat 188 4514 *Radius and mass coefficients
--------------------------------------------------------------------------------
Note on table2.dat, table4.dat, table6.dat:
A2Z+ (hereafter A2Z) is based on the A2Z pipeline described in
Mathur+ (2010A&A...511A..46M 2010A&A...511A..46M).
BAM calculates νmax and Δν according to
Zinn+ (2019ApJ...884..107Z 2019ApJ...884..107Z).
BHM (Elsworth+ 2020RNAAS...4..177E 2020RNAAS...4..177E) is based on the OCT pipeline
(Hekker+ 2010MNRAS.402.2049H 2010MNRAS.402.2049H), and performs hypothesis testing for
solar-like oscillations above the granulation background.
CAN returns νmax and Δν for stars whose autocorrelation
functions have characteristic timescales and rms variability that
accord with a relation expected from solar-like oscillators
(Kallinger+ 2016SciA....2E0654K 2016SciA....2E0654K).
COR (Mosser & Appourchaux 2009A&A...508..877M 2009A&A...508..877M) first fits for
Δν using the autocorrelation of the light curve.
SYD computes νmax and Δν according to
Huber+ (2009CoAst.160...74H 2009CoAst.160...74H).
See Section 3.1.
--------------------------------------------------------------------------------
See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
III/279 : RAVE 5th data release (Kunder+, 2017)
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)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
J/A+A/497/497 : Physical param. from JHK flux (Gonzalez-Hernandez+, 2009)
J/ApJS/224/2 : K2 EPIC stellar properties for 138600 targets (Huber+, 2016)
J/MNRAS/469/4578 : Deep learning classif. in asteroseismology (Hon+, 2017)
J/ApJ/844/102 : KIC star plx from asteroseismology vs Gaia (Huber+, 2017)
J/ApJ/835/83 : K2 GAP data release. I. Campaign 1 (Stello+, 2017)
J/ApJS/239/32 : APOKASC-2 cat. of Kepler evolved stars (Pinsonneault+, 2018)
J/ApJS/236/42 : Asteroseismology of ∼16000 Kepler red giants (Yu+, 2018)
http://archive.stsci.edu/k2/ : K2 mission on MAST home page
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- EPIC [210305942/219612205] EPIC identifier
11- 11 I1 --- C [4/7] K2 campaign number
13- 17 I5 --- Prior [1/18698]? Priority (1)
19- 25 A7 --- State Evolutionary state (2)
27- 33 F7.3 uHz numax-A2Z [3/270]? A2Z+ frequency at maximum
acoustic power (3)
35- 41 F7.3 uHz numax-BAM [3.5/250]? BAM frequency at maximum
acoustic power (3)
43- 49 F7.3 uHz numax-BHM [10/250]? BHM frequency at maximum
acoustic power (3)
51- 57 F7.3 uHz numax-CAN [3/257]? CAN frequency at maximum
acoustic power (3)
59- 65 F7.3 uHz numax-COR [1.9/243]? COR frequency at maximum
acoustic power (3)
67- 73 F7.3 uHz numax-SYD [0/286]? SYD frequency at maximum
acoustic power (3)
75- 80 F6.3 uHz e_numax-A2Z [0.15/35]? Uncertainty in numax-A2Z
82- 88 F7.3 uHz e_numax-BAM [0.05/113]? Uncertainty in numax-BAM
90- 95 F6.3 uHz e_numax-BHM [0.0/47]? Uncertainty in numax-BHM
97-102 F6.3 uHz e_numax-CAN [0.19/18]? Uncertainty in numax-CAN
104-108 F5.3 uHz e_numax-COR [0.1/4.4]? Uncertainty in numax-COR
110-116 F7.3 uHz e_numax-SYD [0/220]? Uncertainty in numax-SYD
118-123 F6.3 uHz dnu-A2Z [0.75/20.5]? A2Z+ large frequency
separation (3)
125-130 F6.3 uHz dnu-BAM [0.008/17.7]? BAM large frequency
separation (3)
132-137 F6.3 uHz dnu-BHM [1.3/23.4]? BHM large frequency separation (3)
139-144 F6.3 uHz dnu-CAN [1/18.8]? CAN large frequency separation (3)
146-151 F6.3 uHz dnu-COR [0.4/19.9]? COR large frequency separation (3)
153-158 F6.3 uHz dnu-SYD [0.7/18.7]? SYD large frequency separation (3)
160-164 F5.3 uHz e_dnu-A2Z [0/2.6]? Uncertainty in dnu-A2Z
166-170 F5.3 uHz e_dnu-BAM [0/2.8]? Uncertainty in dnu-BAM
172-176 F5.3 uHz e_dnu-BHM [0.04/2.2]? Uncertainty in dnu-BHM
178-182 F5.3 uHz e_dnu-CAN [0.009/0.5]? Uncertainty in dnu-CAN
184-188 F5.3 uHz e_dnu-COR [0.05/0.4]? Uncertainty in dnu-COR
190-194 F5.3 uHz e_dnu-SYD [0.02/4.4]? Uncertainty in dnu-SYD
--------------------------------------------------------------------------------
Note (1): The K2 GAP target priority discussed in Section 2 (a smaller numerical
value corresponds to higher priority); serendipitous targets do not
have a populated priority entry.
Note (2): Evolutionary states derived from a machine-learning approach
described in Section 3.2.2; if classified, a star's evolutionary
state is assigned as follows:
RGB = red giant branch star (2132 occurrences),
RGB/AGB = The spectra of these stars from K2 cannot be used to distinguish
between RGB and AGB because both types of stars are shell-burning
stars (669 occurrences),
RC = red clump star (1594 occurrences).
Note (3): Raw asteroseismic parameters from the pipelines described in
Section 3.1.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- EPIC [210306475/218195559] EPIC identifier
11- 17 F7.3 uHz numax [4.7/243]? Mean frequency at maximum
acoustic power (<ν'_max>)
19- 23 F5.3 uHz e_numax [0.002/3.3]? Uncertainty in numax
25 I1 --- Nnu [0/6] Number of pipelines with corrected
frequency at maximum acoustic power
27- 32 F6.3 uHz dnu-corr [0.7/19]? Mean corrected large frequency
separation (<Δν'>)
34- 38 F5.3 uHz e_dnu-corr [0/0.4]? Uncertainty in dnu-corr
40 I1 --- Ndnu [0/6] Number of pipelines with corrected
large frequency separation
42- 46 F5.3 --- S16cor [0.9/1.1]? Sharma+ 2016ApJ...822...15S 2016ApJ...822...15S
large frequency separation
correction (XSharma)
48- 52 F5.3 --- e_S16cor [0/0.12]? Uncertainty in S16cor
54- 59 F6.3 uHz dnu [0.7/18.3]? Mean uncorrected large
frequency separation (<Δν>)
61- 67 F7.3 uHz numax-A2Z-c [4.5/242]? A2Z+ corrected frequency at
maximum acoustic power
69- 75 F7.3 uHz numax-BAM-c [5/222]? BAM corrected frequency at
maximum acoustic power
77- 83 F7.3 uHz numax-BHM-c [9.9/245]? BHM corrected frequency at
maximum acoustic power
85- 91 F7.3 uHz numax-CAN-c [7.7/229]? CAN corrected frequency at
maximum acoustic power
93- 99 F7.3 uHz numax-COR-c [4.7/225]? COR corrected frequency at
maximum acoustic power
101- 107 F7.3 uHz numax-SYD-c [4.8/235]? SYD corrected frequency at
maximum acoustic power
109- 114 F6.3 uHz dnu-A2Z-c [0.7/19]? A2Z+ corrected large frequency
separation
116- 121 F6.3 uHz dnu-BAM-c [1/17.4]? BAM corrected large frequency
separation
123- 128 F6.3 uHz dnu-BHM-c [1.4/19.1]? BHM corrected large frequency
separation
130- 135 F6.3 uHz dnu-CAN-c [1/17.3]? CAN corrected large frequency
separation
137- 142 F6.3 uHz dnu-COR-c [0.7/17.6]? COR corrected large frequency
separation
144- 149 F6.3 uHz dnu-SYD-c [1.2/18.3]? SYD corrected large frequency
separation
151- 154 I4 K Teff [3722/6805] EPIC effective temperature
156- 158 I3 K e_Teff [43/604] Uncertainty in Teff
160- 165 F6.3 [-] [Fe/H] [-2.6/0.3] EPIC metallicity
167- 171 F5.3 [-] e_[Fe/H] [0.05/1.5] Uncertainty in [Fe/H]
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- EPIC [210306475/218195559] EPIC identifier
11- 16 F6.3 --- Kr [3.8/49.3]? Mean radius coefficient
(<K'R>) (1)
18- 23 F6.3 --- e_Kr [0.014/13]? Uncertainty in kr
25- 29 F5.3 --- Km [0.4/5.3]? Mean mass coefficient
(<K'M>) (1)
31- 35 F5.3 --- e_Km [0.01/2.3]? Uncertainty in km
37- 42 F6.3 --- Kr-A2Z [3.8/49.6]? A2Z+ radius coefficient (2)
44- 49 F6.3 --- Kr-BAM [4.3/42.5]? BAM radius coefficient (2)
51- 56 F6.3 --- Kr-BHM [3.8/30.2]? BHM radius coefficient (2)
58- 63 F6.3 --- Kr-CAN [4.5/39.6]? CAN radius coefficient (2)
65- 70 F6.3 --- Kr-COR [3.9/47.6]? COR radius coefficient (2)
72- 77 F6.3 --- Kr-SYD [4.2/34.7]? SYD radius coefficient (2)
79- 84 F6.3 --- e_Kr-A2Z [0.2/10.7]? Uncertainty in Kr-A2Z
86- 91 F6.3 --- e_Kr-BAM [0.03/20.5]? Uncertainty in Kr-BAM
93- 97 F5.3 --- e_Kr-BHM [0.2/4.8]? Uncertainty in Kr-BHM
99-103 F5.3 --- e_Kr-CAN [0.04/3.7]? Uncertainty in Kr-CAN
105-109 F5.3 --- e_Kr-COR [0.1/6.6]? Uncertainty in Kr-COR
111-116 F6.3 --- e_Kr-SYD [0.04/25.8]? Uncertainty in Kr-SYD
118-122 F5.3 --- Km-A2Z [0.4/5.6]? A2Z+ mass coefficient (2)
124-128 F5.3 --- Km-BAM [0.3/4.8]? BAM mass coefficient (2)
130-134 F5.3 --- Km-BHM [0.5/4.2]? BHM mass coefficient (2)
136-140 F5.3 --- Km-CAN [0.3/5.3]? CAN mass coefficient (2)
142-146 F5.3 --- Km-COR [0.4/5.5]? COR mass coefficient (2)
148-152 F5.3 --- Km-SYD [0.6/4.2]? SYD mass coefficient (2)
154-158 F5.3 --- e_Km-A2Z [0.07/2.2]? Uncertainty in Km-A2Z
160-164 F5.3 --- e_Km-BAM [0.02/4.8]? Uncertainty in Km-BAM
166-170 F5.3 --- e_Km-BHM [0.09/1.3]? Uncertainty in Km-BHM
172-176 F5.3 --- e_Km-CAN [0.03/1]? Uncertainty in Km-CAN
178-182 F5.3 --- e_Km-COR [0.06/1.4]? Uncertainty in Km-COR
184-188 F5.3 --- e_Km-SYD [0.02/4.3]? Uncertainty in Km-SYD
--------------------------------------------------------------------------------
Note (1): Computed with re-scaled mean asteroseismic parameters, as
described in Section 3.2.4.
Note (2): Computed with re-scaled pipeline-specific asteroseismic parameters, as
described in Section 3.2.4.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Feb-2021