J/ApJ/837/96 Rotation-Activity Correlations in K-M dwarfs II. (Houdebine+, 2017)
The rotation-activity correlations in K and M dwarfs.
II. New constraints on the dynamo mechanisms in late-K and M dwarfs before and
at the transition to complete convection.
Houdebine E.R., Mullan D.J., Bercu B., Paletou F., Gebran M.
<Astrophys. J., 837, 96-96 (2017)>
=2017ApJ...837...96H 2017ApJ...837...96H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, M-type ; Spectroscopy ; Equivalent widths
Keywords: stars: activity; stars: chromospheres; stars: coronae;
stars: late-type; stars: low-mass; stars: magnetic field
Abstract:
We study the rotation-activity correlations (RACs) in a sample of
stars from spectral type dK4 to dM4. We study RACs using chromospheric
data and coronal data. We study the Ca II line surface fluxes-P/sini
RACs. We fit the RACs with linear homoscedastic and heteroscedastic
regression models. We find that these RACs differ substantially from
one spectral sub-type to another. For dM3 and dM4 stars, we find that
the RACs cannot be described by a simple model, but instead that there
may exist two distinct RAC behaviors for the low-activity and the
high-activity stellar sub-samples, respectively. Although these
results are preliminary and will need confirmation, the data suggest
that these distinct RACs may be associated with different dynamo
regimes. We also study R'HK as a function of the Rossby number R0.
We find (i) for dK4 stars, R'HK as a function of R0 agrees well
with previous results for F-G-K stars and (ii) in dK6, dM2, dM3, and
dM4 stars, at a given R0, the values of R'HK lie at a factor of 3,
10, 20, and 90, respectively, below the F-G-K RAC. Our results suggest
a significant decrease in the efficiency of the dynamo mechanism(s) as
regards chromospheric heating before and at dM3, i.e., before and at
the transition to complete convection. We also show that the ratio of
coronal heating to chromospheric heating LX/LHK increases by a
factor of 100 between dK4 and dM4 stars.
Description:
The spectra that we use for determining the CaII and Hα
equivalent widths in the present study of dK4-dM4 stars came from
three different echelle spectrographs; HARPS (High Accuracy Radial
velocity Planet Search, ESO), SOPHIE (OHP), and FEROS (The Fiber-fed
Extended Range Optical Spectrograph).
The stars in our samples include all stars from all observing programs
that have been carried out with HARPS and SOPHIE for stars belonging
to the following spectral sub-types: dK4, dK6, dM2, and dM3. For dM4
stars, we compiled all measurements of vsini available in the
literature (see Paper I; Houdebine+ 2016, J/ApJ/822/97). For the dK6
and dM3 samples, we also supplemented our own measurements with
measurements available in the literature, notably for active stars
(see Paper I).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 143 127 Equivalent width of the Ca II resonance doublet
and Hα line for our sample of dK6 stars
table3.dat 72 108 The values of vsin(i), P/sin(i) as well as [M/H]
from Paper I (Houdebine+ 2016, J/ApJ/822/97)
for our dM2 stars
table4.dat 113 83 Equivalent width of the Ca II resonance doublet
and Hα line for our sample of dM3 stars
(see Houdebine & Mullan, 2015ApJ...801..106H 2015ApJ...801..106H)
table5.dat 72 97 The values of vsin(i), P/sin(i) and [M/H] from
Paper I (Houdebine+ 2016, J/ApJ/822/97)
for our targets in our list of dM3 stars
table6.dat 109 103 Equivalent width of the Ca II resonance doublet
and Hα line for our sample of dM4 stars
table7.dat 74 106 The values of vsin(i), P/sin(i) and [M/H]
compiled from Paper I
(Houdebine+ 2016, J/ApJ/822/97) for our targets
in our list of dM4 stars
table8.dat 73 384 The log(LHK), log(Lbol), R'HK and R0 for
our samples of dK4, dK6, dM2, dM3 and dM4 stars
--------------------------------------------------------------------------------
See also:
B/pollux : POLLUX database of synthetic stellar spectra (Palacios+ 2010-2015)
III/159 : Ca II H and K Measurements Made at MWO (Duncan+ 1991)
III/231 : The Tycho-2 Spectral Type Catalog (Wright+, 2003)
J/A+A/177/131 : CaII & MgII excess flux density in cool stars (Rutten, 1987)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
J/A+A/327/1039 : Structure and evolution of low-mass stars (Chabrier+ 1997)
J/A+A/331/581 : Rotation and activity in field M dwarfs (Delfosse+ 1998)
J/A+AS/135/319 : ROSAT data of Nearby Stars (Huensch+ 1999)
J/AJ/123/3356 : Palomar/MSU nearby star spectroscopic survey. III.
(Gizis+, 2002)
J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)
J/MNRAS/390/545 : Magnetic field & velocity of early M dwarfs (Donati+, 2008)
J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)
J/A+A/478/507 : Distances & atmospheric param. of MSU stars (Morales+, 2008)
J/MNRAS/390/567 : Magnetic field and velocity of mid M dwarfs (Morin+, 2008)
J/MNRAS/407/1657 : Rotation velocities of dwarf M stars (Houdebine, 2010)
J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010)
J/MNRAS/407/2269 : Polarisation of a sample of late M dwarfs (Morin+, 2010)
J/MNRAS/416/2233 : Rotation velocity of dwarfs K5 stars (Houdebine, 2011)
J/ApJ/743/48 : Rotation periods and X-ray luminosities (Wright+, 2011)
J/MNRAS/421/3189 : CaII and Hα data for dK5/dM4 stars (Houdebine, 2012)
J/MNRAS/426/1591 : CaII equivalent widths of dM1 stars (Houdebine+, 2012)
J/AJ/143/93 : Rotational velocities in early-M stars (Reiners+, 2012)
J/A+A/551/L8 : Chromospheric activity of field stars (Pace, 2013)
J/A+A/556/A15 : Effective temperature scale of M dwarfs (Rajpurohit+, 2013)
J/ApJ/764/3 : Hα indices in M low-mass stars (Robertson+, 2013)
J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)
J/MNRAS/449/2618 : M-dwarfs in Multiples (MinMs) survey. I. (Ward-Duong+, 2015)
J/ApJ/812/3 : MEarth M dwarfs rotation & kinematics (West+, 2015)
J/ApJ/822/97 : RACs in K-M dwarfs. Paper I. (Houdebine+, 2016)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Stellar identifier
14 A1 --- f_Star [2] 2 = FEROS spectra
16- 20 A5 --- N Number of measurements
22 A1 --- l_CaH-H Limit flag on CaH-H
23- 29 F7.3 0.1nm CaH-H [-7.7/-0.05]? HARPS Ca II H line equivalent
width (1)
31- 34 F4.2 0.1nm e_CaH-H [0.01/0.2]? Uncertainty in CaH-H
36 A1 --- l_CaK-H Limit flag on CaH-K
37- 43 F7.3 0.1nm CaK-H [-8.4/-0.05]? HARPS Ca II K line equivalent
width (1)
45- 48 F4.2 0.1nm e_CaK-H [0.01/0.2]? Uncertainty in CaK-H
50- 55 F6.3 0.1nm Ha-H [-1.3/0.8]? HARPS Hα line equivalent
width (1)
57- 61 F5.3 0.1nm e_Ha-H [0.02/0.05]? Uncertainty in Ha-H
63- 67 F5.2 0.1nm CaH-S [-4.3/-0.3]? SOPHIE Ca II H line equivalent
width (1)
69- 72 F4.2 0.1nm e_CaH-S [0.05/0.3]? Uncertainty in CaH-S
74- 78 F5.2 0.1nm CaK-S [-6.3/-0.4]? SOPHIE Ca II K line equivalent
width (1)
80- 83 F4.2 0.1nm e_CaK-S [0.02/0.3]? Uncertainty in CaK-S
85- 90 F6.3 0.1nm Ha-S [-0.3/0.7]? SOPHIE Hα line equivalent
width (1)
92- 96 F5.3 0.1nm e_Ha-S [0.02]? Uncertainty in Ha-S
98-101 F4.2 --- K/H [0.8/2.2]? Ratio of K to H Ca II lines
103-108 F6.3 0.1nm <Ca> [-8/0]? Average Ca II equivalent width (1)
110 A1 --- l_CaFlux Limit flag on CaFlux
111-116 F6.3 10+2W/m2 CaFlux [0.03/20.3]? Ca II H & K lines mean surface
flux (2)
118-123 F6.3 10+2W/m2 CaFluxc [0.4/16.1]? Ca II H & K lines mean surface
flux corrected for metallicity effects
125-129 A5 --- Nb ? Number of measurements used for EWs
131-137 A7 --- S/N-H HARPS Signal-to-Noise (3)
139-143 A5 --- S/N-S SOPHIE Signal-to-Noise (3)
--------------------------------------------------------------------------------
Note (1): In units of Angstroms.
Note (2): In units of 105erg/s/cm2.
Note (3): From the sum of all available spectra.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Stellar identifier
14 A1 --- l_vsini Limit flag on vsini
15- 19 F5.2 km/s vsini [0.4/12.7]? V sin(i) rotational velocity
21 A1 --- l_Per Limit flag on Per
22- 26 F5.2 d Per [1/65.7]? Period divided by inclination
28- 32 F5.2 d e_Per [0.2/28.3]? Lower uncertainty in Per
34- 39 F6.2 d E_Per [0.2/108]? Upper uncertainty on Per
41- 46 F6.3 [Sun] [M/H] [-1.8/0.5]? Metallicity
48 A1 --- l_CaII Limit flag on CaII
49- 55 F7.3 0.1nm CaII [-9.9/-0.1]? Equivalent width of Ca II;
Angstroms (1)
57 A1 --- l_FHK Limit flag on FHK
58- 63 F6.3 10+4mW/m2 FHK [0.4/44]? Ca II H & K lines mean surface flux (2)
65 A1 --- l_FHKc Limit flag on FHKc
66- 72 F7.3 10+4mW/m2 FHKc [0.5/140]? Ca II H & K lines mean surface flux
corrected for metallicity effects (2)
--------------------------------------------------------------------------------
Note (1): From Paper XVIII (Houdebine, 2012, J/MNRAS/421/3189).
Note (2): In units of 104erg/s/cm2.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Stellar identifier
14- 19 A6 --- N Number of measurements
21 A1 --- l_CaH-H Limit flag on CaH-H
22- 28 F7.3 0.1nm CaH-H [-13.4/-0.06]? HARPS Ca II H line equivalent
width (1)
30- 33 F4.2 0.1nm e_CaH-H [0.01/0.5]? Uncertainty in CaH-H
35 A1 --- l_CaK-H Limit flag on CaH-K
36- 42 F7.3 0.1nm CaK-H [-12.8/-0.1]? HARPS Ca II K line equivalent
width (1)
44- 47 F4.2 0.1nm e_CaK-H [0.01/0.5]? Uncertainty in CaK-H
49- 54 F6.3 0.1nm Ha-H [-4.1/0.4]? HARPS Hα line equivalent
width (1)
56- 60 F5.3 0.1nm e_Ha-H [0.02/0.2]? Uncertainty in Ha-H
62- 67 F6.2 0.1nm CaH-S [-16.1/-0.2]? SOPHIE Ca II H line equivalent
width (1)
69- 72 F4.2 0.1nm e_CaH-S [0.01/1]? Uncertainty in CaH-S
74- 79 F6.2 0.1nm CaK-S [-24.5/-0.3]? SOPHIE Ca II K line equivalent
width (1)
81- 84 F4.2 0.1nm e_CaK-S [0.01/2]? Uncertainty in CaK-S
86- 91 F6.3 0.1nm Ha-S [-3.8/0.4]? SOPHIE Hα line equivalent
width (1)
93- 97 F5.3 0.1nm e_Ha-S [0.02/0.2]? Uncertainty in Ha-S
99-102 F4.2 --- K/H [0.8/2]? Ratio of K to H Ca II lines
104 A1 --- l_<Ca> Limit flag on <Ca>
105-111 F7.3 0.1nm <Ca> [-13.1/-0.09]? Average Ca II equivalent width (1)
113 A1 --- f_<Ca> Flag on <Ca> (1=FEROS spectrum)
--------------------------------------------------------------------------------
Note (1): In units of Angstroms.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Stellar identifier
14 A1 --- l_vsini Limit flag on vsini
15- 19 F5.2 km/s vsini [0.5/80]? V sin(i) rotational velocity
21 A1 --- l_Per Limit flag on Per
22- 26 F5.2 d Per [0.2/44]? Period divided by inclination
28- 32 F5.2 d e_Per [0.07/18]? Lower uncertainty in Per
34- 39 F6.2 d E_Per [0.08/330]? Upper uncertainty on Per (1)
41- 46 F6.3 [Sun] [M/H] [-0.9/0.4] Metallicity
49- 55 F7.3 0.1nm CaII [-14.5/-0.09]? Equivalent width of Ca II;
Angstroms (2)
58- 63 F6.3 10+4mW/m2 FHK [0.2/36.2]? Ca II H & K lines mean surface
flux (3)
66- 72 F7.3 10+4mW/m2 FHKc [0.3/40.3]? Ca II H & K lines mean surface flux
corrected for metallicity effects (3)
--------------------------------------------------------------------------------
Note (1): A blank E_Per when a e_Per is present indicates that the upper
uncertainty is infinity.
Note (2): From Paper XVIII (Houdebine, 2012, J/MNRAS/421/3189).
Note (3): In units of 104erg/s/cm2.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Stellar identifier
14 A1 --- N Number of measurements
16- 21 F6.3 0.1nm CaH-F [-9.3/-0.1]? FEROS Ca II H line equivalent
width (1)
23- 26 F4.2 0.1nm e_CaH-F [0.01/0.2]? Uncertainty in CaH-F
28- 34 F7.3 0.1nm CaK-F [-11/0]? FEROS Ca II K line equivalent width (1)
36- 39 F4.2 0.1nm e_CaK-F [0.01/0.2]? Uncertainty in CaK-F
41- 46 F6.3 0.1nm Ha-F [-6/0.4]? FEROS Hα line equivalent
width (1)
48- 51 F4.2 0.1nm e_Ha-F [0.02/0.2]? Uncertainty in Ha-F
53- 59 F7.3 0.1nm <Ca> [-17/-0.09]? Mean Ca II equivalent width
61- 63 I3 --- o_<Ca> [1/137]? Number of measures in <Ca>
65- 70 F6.3 --- SHK [0.5/28.5]? The SHK index
72- 74 I3 --- o_SHK [1/119]? Number of measures in SHK
76- 82 F7.3 0.1nm <Ca>c [-27.3/-0.1]? Mean Ca II equivalent width (2)
84- 86 I3 --- o_<Ca>c [1/119]? Number of measures in <Ca>c
88- 94 F7.3 0.1nm Ha [-11/0.6]? Literature Hα line equivalent
width
96- 97 I2 --- o_Ha [1/54]? Number of measures in Ha
99-105 F7.3 0.1nm <Ca>o [-19.4/-0.1]? Mean Ca II equivalent width (3)
107-109 I3 --- o_<Ca>o [1/256]? Number of measures in <Ca>o
--------------------------------------------------------------------------------
Note (1): In units of Angstroms.
Note (2): Corrected from metallicity effects.
Note (3): When the Hα EW is known but with no observations
of the Ca II EW, we derived the Ca II EW according to the
Hα EW-Ca II EW correlation (see Fig. 8).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Stellar identifier
14- 18 F5.2 km/s vsini [1/56.5]? V sin(i) rotational velocity
20- 25 F6.3 d Per [0.2/16.4]? Period divided by inclination
26- 26 A1 --- u_Per [:] Uncertainty flag on Per
28- 31 F4.2 d e_Per [0.05/7]? Lower uncertainty in Per
33- 37 F5.2 d E_Per [0.05/19]? Upper uncertainty on Per
39- 43 F5.2 [Sun] [M/H] [-1/0.5]? Metallicity
45- 50 F6.3 [Sun] [M/H]c [-0.5/0.3]? Metallicity from radius-metallicity
relation
52- 58 F7.3 0.1nm CaII [-19.4/-0.1]? Equivalent width of Ca II;
Angstroms (1)
60- 67 F8.5 10+4mW/m2 FHK [0.2/28.1]? Ca II H & K line mean surface
flux (2)
69- 74 F6.3 10+4mW/m2 FHKc [0.2/26.6]? Ca II H & K line mean surface flux
corrected for metallicity effects (2)
--------------------------------------------------------------------------------
Note (1): From the compilation of Table 6.
Note (2): In units of 104erg/s/cm2/s.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- SpT Spectral type (K4, K6, M2, M3 or M4)
4- 15 A12 --- Star Stellar identifier
17- 22 F6.3 [10-7W] logLHK [25/29.4] Log Ca II H & K line luminosity;
erg/s
24- 29 F6.3 [10-7W] logLHKc [25.2/28.5]? Log Ca II H & K line
luminosity; erg/s (1)
31- 36 F6.3 [10-7W] logLbol [30.6/33.1] Log bolometric luminosity; erg/s
38- 43 F6.3 --- R'HK [-6.2/-3.4] The R'HK choromospheric index
45- 50 F6.3 --- R'HKc [-6.2/-3.5]? The R'HK choromospheric
index (1)
52- 57 F6.3 [10-7W] logLX [26/30]? Log X-ray luminosity; erg/s
59- 64 F6.3 [-] logLX/Lb [-5.5/-1.9]? Log X-ray to bolometric
luminosities ratio
66- 72 F7.5 --- R0 [0.0005/1.1]? Rossby number (R0=P/τc)
73 A1 --- f_R0 [?] Uncertainty flag on R0
--------------------------------------------------------------------------------
Note (1): Corrected from metallicity effects.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Houdebine & Mullan. 2015ApJ...801..106H 2015ApJ...801..106H
Houdebine et al. Paper I. 2016ApJ...822...97H 2016ApJ...822...97H Cat. J/ApJ/822/97
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Oct-2017