VI/156 M-dwarf Lum-Temp-Radius relationships (Morrell+, 2019)
Exploring the M-dwarf Luminosity - Temperature - Radius Relationships
using Gaia DR2.
Morrell S.A.F, Naylor T.
<Mon. Not. R. Astron. Soc. 489, 2615-2633 (2019)>
=2019MNRAS.489.2615M 2019MNRAS.489.2615M
=2019yCat.6156....0M 2019yCat.6156....0M
ADC_Keywords: Stars, late-type ; Stars, M-type ; Stars, diameters ;
Effective temperatures ; Magnitudes
Keywords: techniques: photometric - stars: fundamental parameters -
stars: late-type - stars: low-mass - stars: magnetic fields
Abstract:
There is growing evidence that M-dwarf stars suffer radius inflation
when compared to theoretical models, suggesting that models are
missing some key physics required to completely describe stars at
effective temperatures (TSED) less than about 4000K. The advent of
Gaia DR2 distances finally makes available large datasets to determine
the nature and extent of this effect.We employ an all-sky sample,
comprising of >15000 stars, to determine empirical relation-ships
between luminosity, temperature and radius.This is accomplished using
only geometric distances and multiwave-band photometry, by utilising a
modified spectral energy distribution fitting method. The radii we
measure show an inflation of 3-7% compared to models, but nomore than
a 1-2% intrinsic spread in the inflated sequence. We show that we
are currently able to determine M-dwarf radii to an accuracy of 2.4%
using our method. However, we determine that this is limited by the
precision of metallicity measurements, which contribute 1.7% to the
measured radius scatter. We also present evidence that stellar
magnetism is currently unable to explain radius inflation in M-dwarfs.
Description:
We have measured the temperature, radius, and luminosity of a sample
of 15274 late K and early M-dwarf stars using a modified SED
fitting method. This method requires only accurate photometry and
precision astrometry and thus adds a fourth method to those used to
evaluate the veracity of stellar models. Importantly, this method
works natively in the Teff-R space which is crucial for the
characterization of exoplanets. We have derived empirical TSED-R and
LSED-R relations, which can be used to characterize exoplanet host
stars and validate stellar evolution models.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
mdwarfp.dat 807 15765 Input data and fitted properties for stars
in our sample (updated version, 16-Oct-2020)
table3.dat 64 1401 Tabulated form of our TSED-R relation
for M-dwarf stars (corrected version)
table4.dat 146 98 Tabulated form of our LSED-R relation for
M-dwarf stars (corrected version)
table5.dat 43 97 Tabulated values of F(L_SED) in equation 16
(corrected version)
tables/* . 4 Tables in fits version (updated version)
v00/* . 9 Files from first version (11-Sep-2019)
v01/* . 9 Files from second version (09-Mar-2020)
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2
(Bailer-Jones+, 2018)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/321 : IPHAS DR2 Source Catalogue (Barentsen+, 2014)
II/328 : AllWISE Data Release (Cutri+ 2013)
II/341 : VPHAS+ DR2 survey (Drew+, 2016)
IV/35 : Gaia DR2-WISE Galactic Plane Matches (Wilson+, 2018)
IX/50 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR6
(XMM-SSC, 2016)
J/MNRAS/432/1203 : Rotation periods of M-dwarf stars (McQuillan+, 2013)
J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)
J/MNRAS/443/2561 : CONCH-SHELL catalog of nearby M dwarfs (Gaidos+, 2014)
J/ApJS/220/16 : SpeX NIR survey of 886 nearby M dwarfs (Terrien+, 2015)
Byte-by-byte Description of file: mdwarfp.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Id [1/15765] Internal identifier for the
object within our catalogue (id)
7- 28 F22.18 deg RAdeg Right ascension of the source (ICRS) at
Ep=2015.5 as given in the Gaia DR2
catalogue (ra)
30- 52 F23.19 deg DEdeg Declination of the source (ICRS) at
Ep=2015.5 as given in the Gaia DR2
catalogue (dec)
54- 72 I19 --- Source Unique source identifier of the star
within Gaia DR2 (source_id)
74- 83 F10.7 mag Gmag [9.0/18.1] G-band mean magnitude of the
star in the Gaia DR2 catalogue
(photgmean_mag)
85- 94 F10.7 mag BPmag [9.8/20.8] Integrated BP mean magnitude
of the star in the Gaia DR2 catalogue
(photbpmean_mag)
96-105 F10.7 mag RPmag [8.1/16.5] Integrated RP mean magnitude
of the star in the Gaia DR2 catalogue
(photrpmean_mag)
107-127 F21.19 mag e_BPmag [0.0/0.3] Uncertainty of the BP mean
magnitude of the star in the Gaia DR2
catalogue (photbpmeanmagerr)
129-150 F22.20 mag e_RPmag [0.0/0.3] Uncertainty of the RP mean
magnitude of the star in the Gaia DR2
catalogue (photrpmeanmagerr)
152-173 F22.14 e-/s FBP [70.8/1558645.7] Integrated BP mean flux
of the star in the Gaia DR2 catalogue
(photbpmean_flux)
175-195 F21.13 e-/s FRP [2151.6/4289144.1] Integrated RP mean
flux of the star in the Gaia DR2
catalogue (photrpmean_flux)
197-217 F21.13 e-/s FG [1119.4/4568808.7] G-band mean flux of
the star in the Gaia DR2 catalogue
(photgmean_flux)
219-230 F12.6 --- chi2AL [56.3/24146.0] Astrometric goodness of
fit in the Gaia DR2 catalogue
(astrometricchi2al)
232-234 I3 --- NgAL [66.0/916.0] No. CCD transits not
downweighted in the astrometric solution
in the Gaia DR2 Catalogue
(astrometricngoodobsal)
236-241 F6.3 mag Jmag [6.9/13.9] J band magnitude of the star
in 2MASS (Jmag_cds)
243-247 F5.3 mag e_Jmag [0.0/0.1] Uncertainty in J band magnitude
of the star in 2MASS (eJmagcds)
249-254 F6.3 mag Hmag [6.3/13.4] H band magnitude of the star
in 2MASS (Hmag_cds)
256-260 F5.3 mag e_Hmag [0.0/0.1] Uncertainty in H band magnitude
of the star in 2MASS (eHmagcds)
262-267 F6.3 mag Kmag [6.0/13.1] Ks band magnitude of the star
in 2MASS (Kmag_cds)
269-273 F5.3 mag e_Kmag [0.0/0.1] Uncertainty in Ks band
magnitude of the star in 2MASS
(eKmagcds)
275-280 F6.3 mag W1mag [5.9/12] W1 band magnitude of the star in
AllWISE (W1mag_cds)
282-286 F5.3 mag e_W1mag [0.0/0.2] Uncertainty in W1 band
magnitude of the star in AllWISE
(eW1magcds)
288-293 F6.3 mag W2mag [5.7/11.8] W2 band magnitude of the star
in AllWISE (W2mag_cds)
295-299 F5.3 mag e_W2mag [0.0/0.1] Uncertainty in W2 band
magnitude of the star in AllWISE
(eW2magcds)
301-306 F6.3 mag W3mag [5.7/11.3] W3 band magnitude of the star
in AllWISE (W3mag_cds)
308-312 F5.3 mag e_W3mag [0.0/0.2] Uncertainty in W3 band
magnitude of the star in AllWISE
(eW3magcds)
314-317 I4 --- ModelNo [0.0/3535.0] Number of the best fitting
model in our grid (model_no)
319-336 F18.15 --- Norm [45.0/51.0] Magnitude normalisation
calculated by the code to scale Zi
to mi,syn (norm)
338-360 F23.18 --- chisq [0.0/3255.6] Goodness of fit for the
best fitting model (chisq)
362-383 F22.18 --- rchisq [0.0/407.0] Goodness of fit per degree of
freedom for the best fitting model
(reduced_chisq)
385-405 F21.19 --- Prob [0.0/1.0] The corresponding probability
of being the best fitting model (prob)
407-428 E22.17 --- rsqr/dsqr Measured radius squared on distance
squared of the target (rsqrondsqr)
430-448 F19.17 Rsun Rad [0.0/1.3] Our measured radius of the
target (in units of R☉) (radius)
450-466 F17.14 pc Dist [9.5/100.0] Estimated distance (in pc)
to the target (dist)
468-484 F17.14 pc b_Dist [9.4/99.8] Lower bound on the confidence
interval of the estimated distance
(in pc) (dist_lbound)
486-503 F18.14 pc B_Dist [9.5/100.5] Upper bound on the confidence
interval of the estimated distance
(in pc) (dist_ubound)
505 I1 --- Nphot [8] The number of photometric data points
used for the SED fitting (nphot)
507-510 I4 K Teff [335/5100] Our measured SED temperature
of the target (Teff)
512-514 F3.1 [cm/s2] logg [4.0/5.5] Our measured surface gravity
of the target (Log(g))
516 I1 --- BadPhot Flag showing whether source is consistent
with contaminated photometry in Gaia DR2
(bad_phot)
518 I1 --- BadAstr Flag indicating whether source is
consistent with contaminated astrometry
in Gaia DR2 (bad_astr)
520 I1 --- BadTeff Flag indicating that the measured TSED
is at a grid boundary (bad_teff)
522 I1 --- Good True if none of bad_phot, bad_astr or
bad_teff are true for the source (good)
524-530 F7.2 K bTeff ? Lower bound on the confidence interval
of our measured TSED (teff_lbound)
532-538 F7.2 K BTeff ? Upper bound on the confidence interval
of our measured TSED (teff_ubound)
540-552 F13.8 [cm/s2] blogg ? Lower bound on the confidence interval
of our measured log(g) (g_lbound)
554-565 F12.8 [cm/s2] Blogg ? Upper bound on the confidence interval
of our measured log(g) (g_ubound)
567-579 F13.9 Rsun bRad ? Lower bound on the confidence interval
of our measured radius (radius_lbound)
581-593 F13.9 Rsun BRad ? Upper bound on the confidence interval
of our measured radius (radius_ubound)
595-609 F15.10 --- tausq68cont ? Value of χ2 within which 68% of
the confidence is bounded within the
cube (tausq68_contour)
611-616 A6 --- UncerSample Sample for which the uncertainties
correspond. For this publication,
it will be 'random' (uncer_sample)
618-640 F23.19 % d08inflation [-44.8/50.4] Radius inflation (in %) from
the Dotter et al. (2008ApJS..178...89D 2008ApJS..178...89D)
4Gyr solar metallicity isochrone
(d08_inflation)
642-665 E24.17 Rsun d08lrcorr Radius residual when corrected for our
luminosity - radius relation
(d08lumcorr_radius)
667-688 F22.18 Lsun Lum ? Luminosity measured for the source when
correcting the radius for metallicity
(lum)
690-710 F21.17 Rsun Radcorr ? Radius of the star when corrected for
the effects of metallicity
(corrected_radius)
712-732 F21.17 Rsun bRadcorr ? Lower bound on the confidence interval
of our metallicity corrected radius
(correctedradiuslbound)
734-754 F21.17 Rsun BRadcorr ? Upper bound on the confidence interval
of our metallicity corrected radius
(correctedradiusubound)
756-762 F7.2 [-] [Fe/H] ? Measured metallicity of the target
(fe_h)
764-782 A19 --- r_[Fe/H] The bibcode corresponding to the source
of the metallicity measurement
(fehbibcode)
784-808 F25.20 Rsun Radcorr2 ? The correction applied to our measured
radius to correct for metallicity,
measured in R☉ (rad_corr)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 K TSED [3000/4400] SED temperature of the source
6- 24 F19.17 Rsun Rad [0.1/0.8] Radius prescribed by the relation
at temperature TSED
26- 44 F19.17 Rsun b_Rad [0.1/0.7] Lower bound radius prescribed by the
relation at temperature TSED
46- 64 F19.17 Rsun B_Rad [0.2/0.8] Upper bound radius prescribed by the
relation at temperature TSED
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 F20.18 Lsun LSED [0.0/0.1] Luminosity of the source from a
SED fit (lsed)
22- 41 F20.18 Rsun Radcorr [0.0/0.7] Radius correction to the D08 4Gyr
isochrone at luminosity LSED
(radius_correction)
43- 65 E23.16 Rsun b_Radcorr [-0.1/0.7] Lower bound radius correction to the
D08 4Gyr isochrone at luminosity LSED
(radiuscorrectionlbound)
67- 86 F20.18 Rsun B_Radcorr [0.0/0.7] Upper bound radius correction to the
D08 4Gyr isochrone at luminosity LSED
(radiuscorrectionubound_
88-106 F19.17 Rsun Rad [0.1/0.7] Radius prescribed by the relation
at luminosity LSED (radius)
108-126 F19.17 Rsun b_Rad [0.1/0.7] Lower bound radius prescribed by the
relation at luminosity LSED (radius_lbound)
128-146 F19.17 Rsun B_Rad [0.2/0.8] Upper bound radius prescribed by the
relation at luminosity LSED (radius_ubound)
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 21 F21.19 Lsun LSED [0.0/0.1] Luminosity of the source from a
SED fit (lum)
23- 43 F21.18 --- fLSED [-0.1/-0.0] Gradient of F(LSED) at the
given luminosity LSED (f_lum)
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Acknowledgements:
Sam Morrell, smorrell(at)astro.ex.ac.uk
History:
11-Sep-2019: on-line version
09-Mar-2020: updated version
16-Oct-2020: uncertainties corrected
(End) Patricia Vannier [CDS] 28-Jul-2019