J/A+A/628/A41 KIC stars in Kepler/XMM-Newton (Pizzocaro+, 2019)
Activity and rotation of the X-ray emitting Kepler stars.
Pizzocaro D., Stelzer B., Poretti E., Raetz S., Micela G., Belfiore A.,
Marelli M., Salvetti D., De Luca A.
<Astron. Astrophys., 628, A41 (2019)>
=2019A&A...628A..41P 2019A&A...628A..41P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; X-ray sources ; Photometry
Keywords: stars: activity - methods: observational - stars: atmospheres -
magnetic fields - X-rays: stars - dynamo
Abstract:
The relation between magnetic activity and rotation in late-type stars
provides fundamental information on stellar dynamos and angular
momentum evolution. Rotation-activity studies found in the literature
suffer from inhomogeneity in the measurement of activity indexes and
rotation periods. We overcome this limitation with a study of the
X-ray emitting, late-type main-sequence stars observed by XMM-Newton
and Kepler. We measured rotation periods from photometric variability
in Kepler light curves. As activity indicators, we adopted the X-ray
luminosity, the number frequency of white-light flares, the amplitude
of the rotational photometric modulation, and the standard deviation
in the Kepler light curves. The search for X-ray flares in the light
curves provided by the EXTraS (Exploring the X-ray Transient and
variable Sky) FP-7 project allows us to identify simultaneous X-ray
and white-light flares. A careful selection of the X-ray sources in
the Kepler field yields 102 main-sequence stars with spectral types
from A to M. We find rotation periods for 74 X-ray emitting
main-sequence stars, 20 of which do not have period reported in the
previous literature. In the X-ray activity-rotation relation, we see
evidence for the traditional distinction of a saturated and a
correlated part, the latter presenting a continuous decrease in
activity towards slower rotators. For the optical activity indicators
the transition is abrupt and located at a period of ∼10d but it can be
probed only marginally with this sample, which is biased towards fast
rotators due to the X-ray selection. We observe seven bona-fide X-ray
flares with evidence for a white-light counterpart in simultaneous
Kepler data. We derive an X-ray flare frequency of ∼0.15d-1,
consistent with the optical flare frequency obtained from the much
longer Kepler time-series.
Description:
Using a complex sample selection approach involving multi-band
photometric characterization and visual inspection of multi-band
images, we identify 125 stars with X-ray detection in the 3XMM-DR5
catalog (Cat. IX/46) that are observed by the Kepler mission.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 99 125 *KIC (Brown et al. 2011, J/AJ/142/112) photometry
all the 125 stars in the Kepler/XMM-Newton
sample
tablea2.dat 103 125 Fundamental stellar parameters for all 125 stars
in the Kepler/XMM-Newton sample
tablea3.dat 68 74 Rotation and flaring parameters derived from the
Kepler light curves for all 74
rotationally-variable main-sequence stars in
the Kepler/XMM-Newton sample
tablea4.dat 65 125 X-ray luminosity (in the 0.2-2keV energy band),
observed NUV and FUV luminosity, and NUV and
FUV chromospheric excess luminosity
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Note on tablea1.dat: with the corrections by Pinsonneault et al. (2012, Cat.
J/ApJS/199/30) for the SLOAN filters and updated magnitudes from the UCAC-4
Catalogue (Zacharias et al., 2012, Cat. I/322).
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See also:
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
IX/46 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR5
(XMM-SSC, 2016)
J/ApJS/199/30 : Effective temperature scale for KIC stars (Pinsonneault+, 2012)
J/ApJ/775/L11 : Stellar rotation periods for KOIs (McQuillan+, 2013)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC KIC ID
10- 15 F6.3 mag Jmag 2MASS J magnitude
17- 22 F6.3 mag Hmag 2MASS H magnitude
24- 29 F6.3 mag Ksmag 2MASS Ks magnitude
31- 36 F6.3 mag Umag ?=- U magnitude
38- 43 F6.3 mag Bmag ?=- B magnitude
45- 50 F6.3 mag Vmag ?=- V magnitude
52- 57 F6.3 mag Kpmag Kepler magnitude
59- 64 F6.3 mag gmag ?=- SDSS g magnitude
66- 71 F6.3 mag rmag ?=- SDSS r magnitude
73- 78 F6.3 mag imag ?=- SDSS i magnitude
80- 85 F6.3 mag zmag ?=- SDSS z magnitude
87- 92 F6.3 mag FUVmag ?=- GALEX FUV magnitude
94- 99 F6.3 mag NUVmag ?=- GALEX NU magnitude
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC KIC ID
10- 13 F4.2 mag AV Absorption in V band
14 A1 --- n_AV [=] = for adopted value
16- 19 F4.2 [cm/s2] logg Surface gravity in solar unit
20 A1 --- n_logg [=] = for adopted value
22- 27 F6.3 [Sun] [Fe/H] Metallicity in solar unit
28 A1 --- n_[Fe/H] [=] = for adopted value
30- 33 I4 K Teff Effective temperature
35- 37 I3 K e_Teff rms uncertainty on effective temperature
39- 44 F6.1 pc d Distance
46- 51 F6.1 pc e_d rms uncertainty on Distance
53- 56 A4 --- r_d Reference for Distance
58- 61 F4.2 Msun M* Stellar mass
63- 66 F4.2 Msun e_M* rms uncertainty on Stellar mass
68- 72 F5.2 [Lsun] logLbol Bolometric luminosity
74- 77 F4.2 [Lsun] e_logLbol rms uncertainty on Bolometric luminosity
79 A1 --- SpType MK spectral type
81- 86 A6 --- Var Variability classification code (1)
89-103 A15 --- Flag Flag (2)
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Note (1): Variability classification code ar follows:
ROT = rotational variability;
ROT UNCL = probably rotational variability but it is not possible to
establish a reliable rotation period
UNCL = unclear periodic variability
NOPER = no apparent periodicity
ECL = eclipsing binary
CONT = contact binary
MULT = multiperiodic
DSCU = delta Scuti-like
GDOR = gamma Dor-like
Note (2): VOSA for the 6 stars for which Teff is the effective temperature of
the best fit of the individual SED with a model of the stellar photosphere,
as described in Sect. 2.1.
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC KIC ID
10- 14 F5.2 d Prot Rotation period from ACF
16- 19 F4.2 --- R0 ?=- Rossby number from Eq. (36) in
Cranmer & Saar (2011ApJ...741...54C 2011ApJ...741...54C)
21- 25 F5.2 % logRper Percentile amplitude of the rotation cycle
after McQuillan et al. (2013, J/ApJ/775/L11)
27- 31 I5 ppm Sph Standard deviation of the whole lightcurve
33- 37 I5 ppm Sph5 Average of the standard deviation for 5
rotation cycles after Mathur et al.
(2014, Space Weather Space Climate, 4, A15)
39- 44 F6.1 ppm Sflat Minimum of the standard deviations from all
quarters for the "flattened" lightcurves
46- 50 F5.2 [mag] logApeak ?=- Median of relative flare peak amplitudes
52- 56 F5.2 [mag] b_logApeak ?=- Minimum relative flare peak amplitude
58- 62 F5.2 [mag] B_logApeak ?=- Maximum relative flare peak amplitude
64- 68 F5.3 d-1 Flarerate ?=- Flare rate
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Byte-by-byte Description of file: tablea4.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC KIC ID
10- 15 F6.2 10+12W LX X-ray luminosity (in the 0.2-2keV energy
band) (in 10+29^erg/s)
17- 22 F6.2 10+12W e_LX rms uncertainty on LX (in 10+29^erg/s)
24- 30 F7.1 10+12W LNUV ? Observed NUV luminosity (in 10+29^erg/s)
32- 38 F7.1 10+12W e_LNUV ? rms uncertainty on LNUV (in 10+29^erg/s)
40- 44 F5.1 10+12W LFUV ? Observed FUV luminosity (in 10+29^erg/s)
46- 50 F5.1 10+12W e_LFUV ? rms uncertainty on LFUX (in 10+29^erg/s)
52- 58 F7.1 10+12W LNUVexc ? NUV chromospheric excess luminosity
(in 10+29^erg/s)
61- 65 F5.1 10+12W LFUVexc ? FUV chromospheric excess luminosity
(in 10+29^erg/s)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 14-Oct-2019