J/ApJ/887/203 Core rotation period measurements of KIC stars (Tayar+, 2019)
Core-envelope coupling in intermediate-mass core-helium burning stars.
Tayar J., Beck P.G., Pinsonneault M.H., Garcia R.A., Mathur S.
<Astrophys. J., 887, 203 (2019)>
=2019ApJ...887..203T 2019ApJ...887..203T
ADC_Keywords: Stars, masses; Abundances; Asteroseismology; Models
Keywords: Stellar evolutionary models; Late stellar evolution; Stellar rotation;
Stellar evolution
Abstract:
Stars between two and three solar masses rotate rapidly on the main
sequence, and the detection of slow core and surface rotation in the
core-helium burning phase for these stars places strong constraints on
their angular momentum transport and loss. From a detailed
asteroseismic study of the mixed-dipole mode pattern in a carefully
selected, representative sample of stars, we find that slow core
rotation rates in the range reported by prior studies are a general
phenomenon and not a selection effect. We show that the core rotation
rates of these stars decline strongly with decreasing surface gravity
during the core He-burning phase. We argue that this is a
model-independent indication of significant rapid angular momentum
transport between the cores and envelopes of these stars. We see a
significant range in core rotation rates at all surface gravities,
with little evidence for a convergence toward a uniform value. We
demonstrate using evolutionary models that measured surface rotation
periods are a biased tracer of the true surface rotation distribution,
and we argue for using stellar models for interpreting the contrast
between core and surface rotation rates. The core rotation rates we
measure do not have a strong mass or metallicity dependence. We argue
that the emerging data strongly favor a model where angular momentum
transport is much more efficient during the core He-burning phase than
in the shell-burning phases that precede and follow it.
Description:
All the stars in our sample have a Kepler sampling of 29.40 minutes
and have been observed for around 4 years; light curves are available
in Mathur+ (2019, doi:10.17909/t9-mrpw-gc07).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 124 106 Properties of the stars studied here
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
J/ApJ/746/16 : Modelling the convection zone (van Saders+, 2012)
J/A+A/537/A120 : Rotational velocities of A-type stars. IV. (Zorec+, 2012)
J/AJ/146/133 : Stellar param. from SDSS-III APOGEE DR10 (Meszaros+, 2013)
J/ApJ/776/67 : Rotational tracks (van Saders+, 2013)
J/A+A/572/A34 : Pulsating solar-like stars in Kepler (Garcia+, 2014)
J/A+A/572/L5 : Evol. state of red giants from seismology (Mosser+, 2014)
J/ApJS/215/19 : APOKASC catalog of Kepler red giants (Pinsonneault+, 2014)
J/ApJ/807/82 : Rotational velocities of APOKASC red giants (Tayar+, 2015)
J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)
J/MNRAS/456/3655 : Masses and ages of red giants (Martig+, 2016)
J/ApJ/823/114 : The Cannon: a new approach to determine masses (Ness+, 2016)
J/A+A/588/A87 : Seismic global parameters of 6111 KIC (Vrard+, 2016)
J/A+A/605/A111 : Surface rotation of Kepler red giant stars (Ceillier+, 2017)
J/ApJS/229/30 : Revised properties of Q1-17 Kepler targets (Mathur+, 2017)
J/A+A/616/A24 : Rotation in RGBs from Kepler asteroseismology (Gehan+, 2018)
J/ApJS/239/32 : APOKASC-2 cat. of Kepler evolved stars (Pinsonneault+, 2018)
J/A+A/626/A121 : Buoyancy radius of γ Dor stars (Ouazzani+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC [2158410/12003742] Kepler Input Cat. ID
10- 16 F7.5 Msun Mass [1.2/3.1] Mass estimate (1)
18- 24 F7.5 [cm/s2] logg [2.4/3.2] Log of surface gravity estimate (1)
26- 32 F7.2 K Teff [4714/5196] Surface temperature (2)
34- 44 F11.8 [-] [Fe/H] [-0.33/0.43] Metallicity (2)
46- 54 F9.6 [-] [C/N] [-1.16/-0.25] Carbon/Nitrogen abundance (2)
56- 63 F8.2 d Psurf [-160.6/165.1]?=-9999 Surface rotation
period (3)
65- 67 A3 --- Group Why star was selected (4)
69- 76 F8.2 s DeltaPi [100.25/393.8]?=-9999 Delta Pi (5)
78- 85 F8.2 --- q [0.1/0.5]?=-9999 Coupling parameter (5)
87- 95 F9.3 uHz split [0.03/0.18]?=-9999 Rotational splitting
values (5)
97-104 F8.2 d Pcore [32.15/193]?=-9999 Core rotation period (5)
106-124 F19.13 d Psurf-t [49.93/312.46]?=-9999 Theoretical surface
rotation period (6)
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Note (1): Mass and surface gravity estimates come from
Pinsonneault+ (2018, J/ApJS/239/32) or the A2Z pipeline
(Mathur+ 2010A&A...511A..46M 2010A&A...511A..46M) with Pinsonneault+ correction factors.
Note (2): Temperatures, metallicities and [C/N] come from APOGEE DR14
(Abolfathi+ 2018ApJS..235...42A 2018ApJS..235...42A);
Note (3): Periods come from Ceillier+ 2017, J/A+A/605/A111
Note (4): Groups indicate why a star was selected as follows:
1 = In Deheuvels+ 2015A&A...580A..96D 2015A&A...580A..96D
2 = Spectroscopic selection, Section 2.2.2;
3 = Surface rotation period from Ceillier+ 2017, J/A+A/605/A111
4 = Asteroseismic sample, Section 2.2.4.
Note (5): Delta Pi, coupling parameters (q), rotational splitting values, and
core rotation periods are derived as discussed in Section 3.2.
Note (6): Theoretical surface rotation periods are derived using the
models discussed in Section 4.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 28-May-2021