2018A&A...609A..12Z


Query : 2018A&A...609A..12Z

2018A&A...609A..12Z - Astronomy and Astrophysics, volume 609A, 12-12 (2018/1-1)

Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators.

ZECHMEISTER M., REINERS A., AMADO P.J., AZZARO M., BAUER F.F., BEJAR V.J.S., CABALLERO J.A., GUENTHER E.W., HAGEN H.-J., JEFFERS S.V., KAMINSKI A., KURSTER M., LAUNHARDT R., MONTES D., MORALES J.C., QUIRRENBACH A., REFFERT S., RIBAS I., SEIFERT W., TAL-OR L. and WOLTHOFF V.

Abstract (from CDS):

Context. The CARMENES survey is a high-precision radial velocity (RV) programme that aims to detect Earth-like planets orbiting low-mass stars.
Aims. We develop least-squares fitting algorithms to derive the RVs and additional spectral diagnostics implemented in the SpEctrum Radial Velocity AnaLyser (SERVAL), a publicly available python code.
Methods. We measured the RVs using high signal-to-noise templates created by coadding all available spectra of each star. We define the chromatic index as the RV gradient as a function of wavelength with the RVs measured in the echelle orders. Additionally, we computed the differential line width by correlating the fit residuals with the second derivative of the template to track variations in the stellar line width.
Results. Using HARPS data, our SERVAL code achieves a RV precision at the level of 1m/s. Applying the chromatic index to CARMENES data of the active star YZ CMi, we identify apparent RV variations induced by stellar activity. The differential line width is found to be an alternative indicator to the commonly used full width half maximum.
Conclusions. We find that at the red optical wavelengths (700-900 nm) obtained by the visual channel of CARMENES, the chromatic index is an excellent tool to investigate stellar active regions and to identify and perhaps even correct for activity-induced RV variations.

Abstract Copyright: © ESO, 2017

Journal keyword(s): methods: data analysis - techniques: radial velocities - techniques: spectroscopic - planets and satellites: detection

Simbad objects: 6

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Number of rows : 6
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 * zet01 Ret PM* 03 17 46.1632605674 -62 34 31.154247481 6.24 6.18 5.54 5.00 4.66 G2.5VHdel1 276 0
2 G 99-49 Er* 06 00 03.5038608130 +02 42 23.596778811   12.97 11.31 10.92 8.43 M3.5Ve 113 0
3 V* YZ CMi Er* 07 44 40.1726285952 +03 33 08.877830321 13.761 12.831 11.225 9.958 8.263 M4.0Ve 809 0
4 BD+20 2465 Er* 10 19 36.2808024653 +19 52 12.014037746   10.82 9.52 9.19   dM3 1199 0
5 NAME Barnard's star BY* 17 57 48.4997994034 +04 41 36.111354228 12.497 11.24 9.511 8.298 6.741 M4V 709 2
6 L 788-37 PM* 22 13 42.8628179730 -17 41 08.676495139   15.32 13.672 13.443   dM4.5 56 0

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2021.10.21-14:59:27

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