Multi-Mask Least-Squares Deconvolution: Extracting RVs using tailored masks
arXiv:2204.13556 · doi:10.1093/mnras/stac1098
Abstract
To push the radial velocity (RV) exoplanet detection threshold, it is crucial to find more reliable radial velocity extraction methods. The Least-Squares Deconvolution (LSD) technique has been used to infer the stellar magnetic flux from spectropolarimetric data for the past two decades. It relies on the assumption that stellar absorption lines are similar in shape. Although this assumption is simplistic, LSD provides a good model for intensity spectra and likewise an estimate for their Doppler shift. We present the Multi-Mask Least-Squares Deconvolution (MM-LSD) RV extraction pipeline which extracts the radial velocity from two-dimensional echelle-order spectra using LSD with multiple tailored masks after continuum normalisation and telluric absorption line correction. The flexibility of LSD allows to exclude spectral lines or pixels at will, providing a means to exclude variable lines or pixels affected by instrumental problems. The MM-LSD pipeline was tested on HARPS-N data for the Sun and selected well-observed stars with 5.7 < Vmag < 12.6. For FGK-type stars with median signal-to-noise above 100, the pipeline delivered RV time series with on average 12 per cent lower scatter as compared to the HARPS-N RV extraction pipeline based on the Cross-Correlation Function technique. The MM-LSD pipeline may be used as a standalone RV code, or modified and extended to extract a proxy for the magnetic field strength.
arXiv commentAccepted for publication in MNRAS. Code available on github: https://github.com/florian-lienhard/MM-LSD. 16 pages, 15 figures
References in corpus (51)
- MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
- Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
- Characteristics of planetary candidates observed by Kepler, II: Analysis of the first four months of data
- Importance Nested Sampling and the MultiNest Algorithm
- No planet for HD 166435
- The CORALIE survey for southern extra-solar planets VII. Two short-period Saturnian companions to HD108147 and HD168746
- ESPRESSO@VLT -- On-sky performance and first results
- Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
- The HARPS-TERRA project I. Description of the algorithms, performance and new measurements on a few remarkable stars observed by HARPS
- Least squares deconvolution of the stellar intensity and polarization spectra
- Using the Sun to estimate Earth-like planets detection capabilities II. Impact of plages
- Planetary detection limits taking into account stellar noise. I. Observational strategies to reduce stellar oscillation and granulation effects
- Detecting Planets Around Very Low Mass Stars with the Radial Velocity Method
- Search for exoplanets with the radial-velocity technique: quantitative diagnostics of stellar activity
- A global cloud map of the nearest known brown dwarf
- Measuring precise radial velocities on individual spectral lines. I. Validation of the method and application to mitigate stellar activity
- Two Earth-sized planets orbiting Kepler-20
- Three years of Sun-as-a-star radial-velocity observations on the approach to solar minimum
- Using the Sun to estimate Earth-like planets detection capabilities.I. Impact of cold spots
- BGLS: A Bayesian formalism for the generalised Lomb-Scargle periodogram
- Extrasolar planets and brown dwarfs around A-F type stars. I. Performances of radial velocity measurements, first analyses of variations
- The SOPHIE search for northern extrasolar planets III. A Jupiter-mass companion around HD 109246
- Kepler-21b: A 1.6REarth Planet Transiting the Bright Oscillating F Subgiant Star HD 179070
- Three Years of HARPS-N High-Resolution Spectroscopy and Precise Radial Velocity Data for the Sun
- HARPS-N observes the Sun as a star
- Kepler-20: A Sun-like Star with Three Sub-Neptune Exoplanets and Two Earth-size Candidates
- Measuring precise radial velocities on individual spectral lines : II. Dependance of stellar activity signal on line depth
- Kepler-21b: A rocky planet around a V = 8.25 magnitude star
- Correcting the spectroscopic surface gravity using transits and asteroseismology. No significant effect on temperatures or metallicities with ARES+MOOG in LTE
- Separating planetary reflex Doppler shifts from stellar variability in the wavelength domain
- Filtering solar-like oscillations for exoplanet detection in radial velocity observations
- A 1.9 Earth radius rocky planet and the discovery of a non-transiting planet in the Kepler-20 system
- ARES+MOOG - a practical overview of an EW method to derive stellar parameters
- Hidden magnetic fields of young suns
- Reconstructing the solar integrated radial velocity using MDI/SOHO
- YARARA: Significant improvement of RV precision through post-processing of spectral time-series
- Performance Verification of the EXtreme PREcision Spectrograph
- On the power spectrum of solar surface flows
- Discovery of a magnetic field in the rapidly-rotating O-type secondary of the colliding-wind binary HD 47129 (Plaskett's star)
- RASSINE: Interactive tool for normalising stellar spectra I. Description and performance of the code
- Stellar Surface Magneto-Convection as a Source of Astrophysical Noise II. Center-to-Limb Parameterisation of Absorption Line Profiles and Comparison to Observations
- Wobble: A Data-driven Analysis Technique for Time-series Stellar Spectra
- Impact of micro-telluric lines on precise radial velocities and its correction
- ROPS: A New Search for Habitable Earths in the Southern Sky
- Exoplanet Imitators: A test of stellar activity behavior in radial velocity signals
- Unexpectedly strong effect of supergranulation on the detectability of Earth twins orbiting Sun-like stars with radial velocities
- A robust, template-free approach to precise radial velocity extraction
- The SpaceInn-SISMA database: characterization of a large sample of variable and active stars by means of HARPS spectra
- K2-263b: A 50-day period sub-Neptune with a mass measurement using HARPS-N
- On the use of the first-order moment approach for measurements of H_eff from LSD profiles
- A Hermite-Gaussian Based Radial Velocity Estimation Method
Cited by in corpus (5)
- Statistical methods for exoplanet detection with radial velocities
- Unsigned magnetic flux proxy from solar optical intensity spectra
- Hyades Member K2-136c: The Smallest Planet in an Open Cluster with a Precisely Measured Mass
- Using Doppler Imaging to model stellar activity and search for planets around Sun-like stars
- A.C.I.D -- An Improved LSD Technique for Accurate Line Profile Retrieval