The CARMENES search for exoplanets around M dwarfs. Mapping stellar activity indicators across the M dwarf domain

Abstract

Stellar activity poses one of the main obstacles for the detection and characterisation of small exoplanets around cool stars, as it can induce radial velocity (RV) signals that can hide or mimic the presence of planetary companions. Several indicators of stellar activity are routinely used to identify activity-related signals in RVs, but not all indicators trace exactly the same activity effects, nor are any of them always effective in all stars. We evaluate the performance of a set of spectroscopic activity indicators for M dwarf stars with different masses and activity levels with the aim of finding a relation between the indicators and stellar properties. In a sample of 98 M dwarfs observed with CARMENES, we analyse the temporal behaviour of RVs and nine spectroscopic activity indicators: cross-correlation function (CCF) full-width-at-half-maximum (FWHM), contrast, and bisector inverse slope (BIS), chromatic index (CRX), differential line width (dLW), and indices of the chromospheric lines H$\alpha$ and calcium infrared triplet. A total of 56 stars of the initial sample show periodic signals related to activity in at least one of these ten parameters. RV is the parameter for which most of the targets show an activity-related signal. CRX and BIS are effective activity tracers for the most active stars in the sample, especially stars with a relatively high mass, while for less active stars, chromospheric lines perform best. FWHM and dLW show a similar behaviour in all mass and activity regimes, with the highest number of activity detections in the low-mass, high-activity regime. Most of the targets for which we cannot identify any activity-related signals are stars at the low-mass end of the sample. These low-mass stars also show the lowest RV scatter, which indicates that ultracool M dwarfs could be better candidates for planet searches than earlier types, which show larger RV jitter.

arXiv comment16 pages, 8 figures, 1 table (37 pages, 14 figures, 12 tables with appendices). Accepted for publication in A&A

References in corpus (84)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Understanding the Lomb-Scargle Periodogram
• No planet for HD 166435
• The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample
• Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample
• Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system
• Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• Large-scale magnetic topologies of late M dwarfs
• Large-scale magnetic topologies of mid-M dwarfs
• A Gaussian process framework for modelling stellar activity signals in radial velocity data
• Assessing statistical significance of periodogram peaks
• How to Constrain Your M dwarf II: the mass-luminosity-metallicity relation from 0.075 to 0.70$M_{\odot }$
• Spectroscopic Properties of Cool Stars in the SDSS: An Analysis of Magnetic Activity and a Search for Subdwarfs
• Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
• Search for Associations Containing Young stars (SACY): I. Sample & Searching Method
• Using the Sun to estimate Earth-like planets detection capabilities II. Impact of plages
• The rotation and Galactic kinematics of mid M dwarfs in the Solar Neighborhood
• A Spectroscopic Catalog of the Brightest (J<9) M Dwarfs in the Northern Sky
• The HARPS search for southern extra-solar planets. X. A m sin i = 11 Mearth planet around the nearby spotted M dwarf GJ 674
• The CARMENES search for exoplanets around M dwarfs: High-resolution optical and near-infrared spectroscopy of 324 survey stars
• Solar-like oscillations in alpha Centauri B
• TW Hydrae: evidence of stellar spots instead of a Hot Jupiter
• A planet within the debris disk around the pre-main-sequence star AU Microscopii
• Stellar activity of planetary host star HD 189733
• Near-infrared Metallicities, Radial Velocities and Spectral Types for 447 Nearby M Dwarfs
• Magnetic Cycles and Rotation Periods of Late Type Stars from photometric time series
• Search for exoplanets with the radial-velocity technique: quantitative diagnostics of stellar activity
• Rotation periods of late-type dwarf stars from time-series high-resolution spectroscopy of chromospheric indicators
• The CARMENES search for exoplanets around M dwarfs: Different roads to radii and masses of the target stars
• CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
• The low-level radial velocity variability in Barnard's star (=GJ 699). Secular acceleration, indications for convective redshift, and planet mass limits
• Ghost in the time series: no planet for Alpha Cen B
• The HARPS search for southern extra-solar planets XLI. A dozen planets around the M dwarfs GJ 3138, GJ 3323, GJ 273, GJ 628, and GJ 3293
• The CARMENES search for exoplanets around M dwarfs. First visual-channel radial-velocity measurements and orbital parameter updates of seven M-dwarf planetary systems
• Using the Sun to estimate Earth-like planets detection capabilities.I. Impact of cold spots
• A candidate super-Earth planet orbiting near the snow line of Barnard's star
• The acoustic spectrum of alpha Cen A
• A Long-Period Jupiter-Mass Planet Orbiting the Nearby M Dwarf GJ849
• Radial Velocity Detection of Earth-mass Planets in the Presence of Activity Noise: The Case of Alpha Centauri Bb
• Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program II. Activity and radial velocity
• Ultra-high-precision velocity measurements of oscillations in alpha Cen A
• The HARPS search for southern extra-solar planets XXXV. The interesting case of HD41248: stellar activity, no planets?
• Spitzer Observations Confirm and Rescue the Habitable-Zone Super-Earth K2-18b for Future Characterization
• Correcting HIRES radial velocities for small systematic errors
• New constraints on the planetary system around the young active star AU Mic. Two transiting warm Neptunes near mean-motion resonance
• The CARMENES search for exoplanets around M dwarfs. Activity indicators at visible and near-infrared wavelengths
• CARMENES input catalogue of M dwarfs IV. New rotation periods from photometric time series
• A high-resolution spectroscopic survey of late-type stars: chromospheric activity, rotation, kinematics, and age
• CARMENES input catalogue of M dwarfs II. High-resolution imaging with FastCam
• Evidence against the young hot-Jupiter around BD +20 1790
• The CARMENES search for exoplanets around M dwarfs. Radial velocities and activity indicators from cross-correlation functions with weighted binary masks
• Line-profile variations in radial-velocity measurements: Two alternative indicators for planetary searches
• Do stellar magnetic cycles influence the measurement of precise radial velocities?
• Characterisation of the radial velocity signal induced by rotation in late-type dwarfs
• SPIRou Input Catalogue: Global properties of 440 M dwarfs observed with ESPaDOnS at CFHT
• Photospheric activity, rotation, and radial velocity variations of the planet-hosting star CoRoT-7
• HADES RV Programme with HARPS-N at TNG. VII. Rotation and activity of M-Dwarfs from time-series high-resolution spectroscopy of chromospheric indicators
• RACE-OC Project: Rotation and variability in the epsilon Chamaeleontis, Octans, and Argus stellar associations
• Modelling the photosphere of active stars for planet detection and characterization
• The CARMENES search for exoplanets around M dwarfs: Radial-velocity variations of active stars in visual-channel spectra
• Variability of stellar granulation and convective blueshift with spectral type and magnetic activity. I. K and G main sequence stars
• Activity-induced radial velocity jitter in a flaring M dwarf
• Formation of starspots in self-consistent global dynamo models: Polar spots on cool stars
• Radial Velocity Variations of Photometrically Quiet, Chromospherically Inactive Kepler Stars: A Link Between RV Jitter and Photometric Flicker
• GJ1214: Rotation period, starspots, and uncertainty on the optical slope of the transmission spectrum
• The CARMENES search for exoplanets around M dwarfs. Measuring precise radial velocities in the near infrared: the example of the super-Earth CD Cet b
• Estimating Stellar Radial Velocity Variability from Kepler and GALEX: Implications for the Radial Velocity Confirmation of Exoplanets
• Stellar Activity and its Implications for Exoplanet Detection on GJ 176
• Stellar Surface Magneto-Convection as a Source of Astrophysical Noise III. Sun-as-a-star Simulations and Optimal Noise Diagnostics
• The CARMENES search for exoplanets around M dwarfs: Nine new double-line spectroscopic binary stars
• Toward Extremely Precise Radial Velocities: II. A Tool For Using Multivariate Gaussian Processes to Model Stellar Activity
• The CARMENES search for exoplanets around M dwarfs: Convective shift and starspot constraints from chromatic radial velocities
• The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti
• The CARMENES search for exoplanets around M dwarfs. Period search in H$\alpha$, Na I D, and Ca II IRT lines
• The correlation between photometric variability and radial velocity jitter, based on TESS and HARPS observations
• Understanding stellar activity-induced radial velocity jitter using simultaneous K2 photometry and HARPS RV measurements
• The GAPS Programme with HARPS-N at TNG XVII. Line profile indicators and kernel regression as diagnostics of radial-velocity variations due to stellar activity in solar-like stars
• Estimating the p-mode frequencies of the solar twin 18 Sco
• No Planet Around HD 219542 B
• Search for Nearby Earth Analogs. III. Detection of ten new planets, three planet candidates, and confirmation of three planets around eleven nearby M dwarfs
• Frequency of planets orbiting M dwarfs in the Solar neighbourhood
• Measuring precise radial velocities and cross-correlation function line-profile variations using a Skew Normal density
• HADES RV Programme with HARPS-N at TNG VI. GJ 3942 b behind dominant activity signals

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• Correlation between activity indicators: H$\alpha$ and Ca II lines in M-dwarf stars
• An Early Catalog of Planet Hosting Multiple Star Systems of Order Three and Higher
• The CARMENES search for exoplanets around M dwarfs. Line-by-line sensitivity to activity in M dwarfs
• A Study of the Magnetic Activity and Variability of GJ 436
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• Gl 725A b: a potential super-Earth detected with SOPHIE and SPIRou in an M dwarf binary system at 3.5 pc
• Non-radial oscillations mimicking a brown dwarf orbiting the cluster giant NGC 4349 No. 127
• Multibeam SETI Observations toward Nearby M dwarfs with FAST
• The CARMENES search for exoplanets around M dwarfs : Understanding the wavelength dependence of radial velocity measurements
• The Interpolation Constraint in the RV Analysis of M-Dwarfs Using Empirical Templates
• An Hα Transit of HD 189733b to Assess Stellar Activity Across the Transit Chord Close to JWST Observations
• TOI-1201 b: A mini-Neptune transiting a bright and moderately young M dwarf