J/ApJ/743/48 Stars with rotation periods and X-ray luminosities (Wright+, 2011)
The stellar-activity-rotation relationship and the evolution of stellar dynamos.
Wright N.J., Drake J.J., Mamajek E.E., Henry G.W.
<Astrophys. J., 743, 48 (2011)>
=2011ApJ...743...48W 2011ApJ...743...48W
ADC_Keywords: Clusters, open ; Stars, late-type ; Stars, normal ; X-ray sources
Magnetic fields
Keywords: stars: activity - stars: coronae - stars: evolution -
stars: late-type - stars: magnetic field - stars: rotation -
X-rays: stars
Abstract:
We present a sample of 824 solar and late-type stars with X-ray
luminosities and rotation periods. This is used to study the
relationship between rotation and stellar activity and derive a new
estimate of the convective turnover time. From an unbiased subset of
this sample the power law slope of the unsaturated regime,
LX/L{bol}∝Roβ, is fit as β=-2.70±0.13. This
is inconsistent with the canonical β=-2 slope to a confidence of
5σ, and argues for an additional term in the dynamo number
equation. From a simple scaling analysis this implies
ΔΩ/Ω∝Ω0.7, i.e. the differential
rotation of solar-type stars gradually declines as they spin down.
Super-saturation is observed for the fastest rotators in our sample
and its parametric dependencies are explored. Significant correlations
are found with both the corotation radius and the excess polar
updraft, the latter theory providing a stronger dependence and being
supported by other observations. We estimate mass-dependent empirical
thresholds for saturation and super- saturation and map out three
regimes of coronal emission. Late F-type stars are shown never to pass
through the saturated regime, passing straight from super-saturated to
unsaturated X-ray emission. The theoretical threshold for coronal
stripping is shown to be significantly different from the empirical
saturation threshold (Ro<0.13), suggesting it is not responsible.
Instead we suggest that a different dynamo configuration is at work in
stars with saturated coronal emission. This is supported by a
correlation between the empirical saturation threshold and the time
when stars transition between convective and interface sequences in
rotational spin-down models.
Description:
Photometric and derived stellar parameters for 824 solar- and
late-type stars from nearby open clusters and the field, including
rotation periods and X-ray luminosities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 185 824 Activity-rotation properties for 824 stars --
updated version by the author
refs.dat 131 65 References
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Default source name (1)
25- 30 I6 --- HD ? Henry Draper catalog number (Cat. III/135)
32- 37 I6 --- HIP ? Hipparcos catalog number (Cat. I/239)
39- 45 A7 --- GJ Catalog of nearby stars source name (Cat. V/70)
47- 55 A9 --- GCVS ? General Catalog of Variable Stars source name
(Cat. B/gcvs)
57- 72 A16 --- 2MASS 2MASS source name (HHMMSSss+DDMMSSs; J2000 -
Cat. II/246)
74- 75 I2 h RAh ? Right Ascension J2000 (hours)
77- 78 I2 min RAm ? Right Ascension J2000 (minutes)
80- 84 F5.2 s RAs ? Right Ascension J2000 (seconds)
86 A1 --- DE- ? Declination J2000 (sign)
87- 88 I2 deg DEd ? Declination J2000 (degrees)
90- 91 I2 arcmin DEm ? Declination J2000 (minutes)
93- 96 F4.1 arcsec DEs ? Declination J2000 (seconds)
98-105 A8 --- Cluster ? Name of open cluster that star is part of
(or 'Field')
107-111 F5.1 pc Dist ? Distance to star (2)
113-117 F5.2 mag Vmag ? Observed V magnitude of star
119-122 F4.2 mag V-K Dereddened V-K colour of star (3)
124-128 A5 --- SpT ? Spectral type of star
130-132 A3 --- r_SpT ? Reference for spectral type, in refs.dat file
134-138 F5.2 [10-7W] logLx Logarithm of the intrinsic X-ray luminosity of
the star
140-142 A3 --- r_logLx Reference for X-ray luminosity in refs.dat file
144-148 F5.2 d Prot Rotation period of the star
150-153 A4 --- r_Prot Reference for rotation period, in refs.dat file
155-158 F4.2 Msun M* Mass of the star (4)
160-163 F4.2 Rsun R* Radius of the star (4)
165-169 F5.2 Lsun L* Bolometric luminosity of the star (4)
171-174 I4 K Teff Effective temperature of the star (4)
176-179 F4.2 --- dcz Height of the radiative-convective boundary
(as a function of the stellar radius) (4)
181-185 F5.2 [---] Lx/bol Logarithm of the X-ray to bolometric luminosity
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Note (1): 202 stars have no identifier; just a position.
Note (2): Taken either from known cluster distances from the literature,
individual stellar parallaxes or fits to main-sequence models (see paper).
Note (3): Derived from spectral types where appropriate (see paper).
Cluster stars dereddened using known cluster extinction.
Note (4): from Siess et al. (2000A&A...358..593S 2000A&A...358..593S) model.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Ref Reference code
6- 24 A19 --- BibCode BibCode
26- 56 A31 --- Aut Author's name
58-131 A74 --- Com Comments
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Acknowledgements:
Nicholas Wright, <n. j. wright at keele.ac.uk>
History:
* 09-Feb-2012: on-line version
* 28-Feb-2013: some names corrected
* 03-Jun-2019: Some distances revised by the author
(End) Nicholas Wright [SAO, USA], Patricia Vannier [CDS] 09-Feb-2012