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J/A+A/614/A122      Radial-velocity of CARMENES M dwarfs      (Tal-Or+, 2018)

The CARMENES search for exoplanets around M dwarfs. Radial-velocity variations of active stars in visual-channel spectra. Tal-Or L., Zechmeister M., Reiners A., Jeffers S.V., Schoefer P., Quirrenbach A., Amado P.J., Ribas I., Caballero J.A., Aceituno J., Bauer F.F., Bejar V.J.S., Czesla S., Dreizler S., Fuhrmeister B., Hatzes A.P., Johnson E.N., Kurster M., Lafarga M., Montes D., Morales J.C., Reffert S., Sadegi S., Seifert W., Shulyak D. <Astron. Astrophys. 614, A122 (2018)> =2018A&A...614A.122T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type; Stars, M-type; Radial velocities; Balmer lines Keywords: stars: late-type - stars: activity - stars: rotation - techniques: radial velocities Abstract: Previous simulations predicted the activity-induced radial-velocity (RV) variations of M dwarfs to range from ∼1cm/s to ∼1km/s, depending on various stellar and activity parameters. We investigate the observed relations between RVs, stellar activity, and stellar parameters of M dwarfs by analyzing CARMENES high-resolution visual-channel spectra (0.5-1um), which were taken within the CARMENES RV planet survey during its first 20 months of operation. During this time, 287 of the CARMENES- sample stars were observed at least five times. From each spectrum we derived a relative RV and a measure of chromospheric Halpha emission. In addition, we estimated the chromatic index (CRX) of each spectrum, which is a measure of the RV wavelength dependence. Despite having a median number of only 11 measurements per star, we show that the RV variations of the stars with RV scatter of >10m/s and a projected rotation velocity vsini>2km/s are caused mainly by activity. We name these stars 'active RV-loud stars' and find their occurrence to increase with spectral type: from ∼3% for early-type M dwarfs (M0.0-2.5V) through ∼30% for mid-type M dwarfs (M3.0-5.5V) to >50% for late-type M dwarfs (M6.0-9.0V). Their RV-scatter amplitude is found to be correlated mainly with vsini. For about half of the stars, we also find a linear RV-CRX anticorrelation, which indicates that their activity-induced RV scatter is lower at longer wavelengths. For most of them we can exclude a linear correlation between RV and Halpha emission. Our results are in agreement with simulated activity-induced RV variations in M dwarfs. The RV variations of most active RV-loud M dwarfs are likely to be caused by dark spots on their surfaces, which move in and out of view as the stars rotate. Description: The catalogue contains the data presented in Figures 5 and A.1 of the source paper. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file stars.dat 63 31 List of studied stars table.dat 72 649 The data presented in Figures 5 and A1
See also: J/A+A/577/A128 : CARMENES input catalog of M dwarfs I (Alonso-Floriano+, 2015) J/A+A/597/A47 : CARMENES input catalog of M dwarfs II (Cortes-Contreras+ 2017) J/A+A/609/A117 : CARMENES radial velocity curves of 7 M-dwarf (Trifonov+, 2018) J/A+A/609/L5 : CARMENES radial velocity curves of HD147379 b (Reiners+, 2018) J/A+A/612/A49 : 324 CARMENES M dwarfs velocities (Reiners+, 2018) Byte-by-byte Description of file: stars.dat
Bytes Format Units Label Explanations
1- 11 A11 --- Karmn Karmn designation 13- 14 I2 h RAh Right ascension (J2000) 16- 17 I2 min RAm Right ascension (J2000) 19- 23 F5.2 s RAs Right ascension (J2000) 25 A1 --- DE- Declination sign (J2000) 26- 27 I2 deg DEd Declination (J2000) 29- 30 I2 arcmin DEm Declination (J2000) 32- 35 F4.1 arcsec DEs Declination (J2000) 37- 39 I3 --- N Number of measurments in table.dat 41- 63 A23 --- SName Simbad name
Byte-by-byte Description of file: table.dat
Bytes Format Units Label Explanations
1- 11 A11 --- Karmn Karmn designation 12- 18 F7.1 m/s RV Radial velocity 20- 25 F6.1 m/s e_RV Radial velocity error 27- 34 F8.1 --- CRX Chromatic index (in m/s/Neper) 36- 42 F7.1 --- e_CRX Chromatic index error (in m/s/Neper) 44- 50 F7.1 1000m+2/s+2 dLW Differential line width 52- 58 F7.1 1000m+2/s+2 e_dLW dLW error 60- 65 F6.3 --- log(LHa/Lbol) ? Halpha luminosity 67- 72 F6.3 --- e_log(LHa/Lbol) ? Halpha luminosity error
Acknowledgements: Lev Tal-Or, levtalor(at)astro.physik.uni-goettingen.de Inst. fur Astrophysik Univ. Goettingen
(End) L. Tal-Or [Inst. fur Astrophysik Goettingen], P. Vannier [CDS] 08-Mar-2018
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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