J/A+A/646/A77 Chromospheric activity from AMBRE-HARPS (Gomes da Silva+, 2021)
Stellar chromospheric activity of 1,674 FGK stars from the AMBRE-HARPS sample.
I. A catalogue of homogeneous chromospheric activity.
Gomes da Silva J., Santos N.C., Adibekyan V., Sousa S.G., Campante T.L.,
Figueira P., Bossini D., Delgado-Mena E., Monteiro M.J.P.F.G.,
de Laverny P., Recio-Blanco A., Lovis C.
<Astron. Astrophys. 646, A77 (2021)>
=2021A&A...646A..77G 2021A&A...646A..77G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Effective temperatures ; Abundances ;
Stars, masses ; Stars, ages
Keywords: catalogs - stars: activity
Abstract:
The main objective of this project is to characterise chromospheric
activity of FGK stars from the HARPS archive. We start, in this first
paper, by presenting a catalogue of homogeneous determined
chromospheric emission (CE), stellar atmospheric parameters and ages
for 1,674 FGK main sequence (MS), subgiant, and giant stars. The
analysis of CE level and variability is also performed.
We measured CE in the CaII lines using more than 180000
high-resolution spectra from the HARPS spectrograph, as compiled in
the AMBRE project, obtained between 2003 and 2019. We converted the
fluxes to bolometric and photospheric corrected chromospheric emission
ratio, R'HK. Stellar atmospheric parameters Teff, logg, and
[Fe/H] were retrieved from the literature or determined using an
homogeneous method. M*, R*, and ages were determined
from isochrone fitting.
We show that our sample has a distribution of CE for MS stars that is
consistent with an unbiased sample of solar-neighbour MS stars. We
analysed the CE distribution for the different luminosity classes and
spectral types and confirmed the existence of the very inactive stars
(VIS) and very active stars (VAS) populations at R'HK←5.1 and
>-4.2dex, respectively. We found indications that the VIS population
is composed mainly of subgiant and giant stars and that R'HK=-5.1dex
marks a transition in stellar evolution.
Overall, CE variability decreases with decreasing CE level but its
distribution is complex.
There appears to be at least three regimes of variability, for
inactive, active and very active stars, with the inactive and active
regimes separated by a diagonal, extended Vaughan-Preston (VP) gap. We
show that stars with low activity levels do not necessarily have low
variability.
In the case of K dwarfs which show high CE variability, inactive and
active stars have similar levels of activity variability. This means
that activity levels alone are not enough to infer about the activity
variability of a star.
We also explained the shape of the VP gap observed in the distribution
of CE by using the CE variability-level diagram.
In the CE variability-level diagram, the Sun is located in the high
variability region of the inactive MS stars zone.
A method to extract the probability density function of the CE
variability for a given R'HK level is discussed, and a python code
to retrieve it is provided.
Description:
We present a catalogue of 1674 FGK MS, subgiant, and giant stars with
more than 180 000 observations from the HARPS archive taken between
2003 and 2019. The vast majority of the stars are in the solar
neighbourhood at less than 100pc away. The catalogue has a maximum
time-span of ∼15.5 years. We have 428 stars with an observation
time-span longer than 10 years, 178 of them with more than 50
individual nights of observation. These stars with long time-spans
(and therefore high-accuracy median activity levels) constitute a
prime sample with which to study stellar rotation, cycles, and
evolution. These time series will be reported in the following papers
of this series.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 372 1674 Catalogue data
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Star Stellar main identification in SIMBAD
25- 29 I5 --- Nobs Total number of observations
31- 33 I3 --- Nnights Total number of nights
35- 38 I4 d Tspan Timespan of observations
40- 42 I3 --- snr-med Median signal-to-noise ratio
44- 66 A23 --- DateStart Date of start of observations
68- 90 A23 --- DateEnd Date of end of observations
92- 97 F6.3 mag Vmag ? Apparent V-band magnitude (dereddened)
99-103 F5.3 mag e_Vmag ? Apparent V-band magnitude uncertainty
105-123 A19 --- r_Vmag Apparent V-band magnitude reference
125-130 F6.3 mag B-V ? B-V colour (dereddened)
132-136 F5.3 mag e_B-V ? B-V colour uncertainty
138-156 A19 --- r_B-V B-V colour reference
158-164 F7.3 arcsec plx ? Parallax
166-171 F6.3 arcsec e_plx ? Parallax uncertainty
173-191 A19 --- r_plx Parallax reference
193-199 F7.2 pc d ? Geometric distance
201 I1 --- Nplt ? Number of planets in system
(as of 2019-12-12)
203-204 A2 --- SpType Spectral type
206-209 I4 K Teff ? Effective temperature
211-215 F5.1 K e_Teff ? Effective temperature uncertainty
217-220 F4.2 [cm/s2] logg ? Logarithm of surface gravity
222-225 F4.2 [cm/s2] e_logg ? Logarithm of surface gravity uncertainty
227-231 F5.2 [Sun] [Fe/H] ? Metallicity
233-236 F4.2 [Sun] e_[Fe/H] ? Metallicity uncertainty
238-256 A19 --- r_Teff Reference for teff, logg, and feh
258-262 F5.3 Msun Mass ? Mass
264-268 F5.3 Msun e_Mass ? Mass uncertainty
270-275 F6.3 Rsun Radius ? Radius
277-281 F5.3 Rsun e_Radius ? Radius uncertainty
283-288 F6.3 Gyr Age ? Age
290-295 F6.3 Gyr e_Age ? Age uncertainty
297-302 F6.4 --- SMWmed Median S-index in Mt. Wilson scale
304-309 F6.4 --- SMWwmean Weighted mean S-index in Mt. Wilson scale
311-316 F6.4 --- e_SMW Uncertainty of S-index in Mt. Wilson scale
318-323 F6.4 --- s_SMW Weighted standard deviation of S-index
in Mt. Wilson scale
325-331 F7.4 --- logRHKmed ? Median log R'HK index
333-339 F7.4 --- logRHKwmean ? Weighted mean log R'HK index
341-346 F6.4 --- e_logRHK ? Uncertanty on log R'HK index
348-353 F6.3 --- R5med ? Median R5 index (R5 = R'HK x 10^5)
355-360 F6.3 --- R5wmean ? Weighted mean R5 index
362-366 F5.3 --- e_R5 ? Uncertainty on R5 index
368-372 F5.3 --- s_R5 ? Weighted standard deviation
of R5 index
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Acknowledgements:
Joao Silva, Joao.Silva(at)astro.up.pt
(End) Patricia Vannier [CDS] 17-Dec-2020