J/A+A/624/A94 The role of the host star's metallicity (Maldonado+, 2019)
Connecting substellar and stellar formation: the role of the host star's
metallicity.
Maldonado J., Villaver E., Eiroa C., Micela G.
<Astron. Astrophys. 624, A94 (2019)>
=2019A&A...624A..94M 2019A&A...624A..94M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Abundances, [Fe/H] ; Spectroscopy ; Planets
Keywords: techniques: spectroscopic - stars: abundances -stars: late-type -
planetary systems
Abstract:
Most of our current understanding of the planet formation mechanism is
based on the planet metallicity correlation derived mostly from
solar-type stars harbouring gas-giant planets.
To achieve a more extensive grasp on the substellar formation process,
we aim to analyse in terms of their metallicity a diverse sample of
stars (in terms of mass and spectral type) covering the whole range of
possible outcomes of the planet formation process (from planetesimals
to brown dwarfs and low-mass binaries).
Our methodology is based on the use of high-precision stellar
parameters derived by our own group in previous works from
high-resolution spectra by using the iron ionisation and equilibrium
conditions. All values were derived in an homogeneous way, except for
the M dwarfs where a methodology based on the use of pseudo equivalent
widths of spectral features was used. Our results show that as the
mass of the substellar companion increases the metallicity of the host
star tends to lower values. The same trend is maintained when
analysing stars with low-mass stellar companions and a tendency
towards a wide range of host star's metallicity is found for systems
with low-mass planets. We also confirm that more massive planets tend
to orbit around more massive stars.
The core-accretion formation mechanism for planet formation achieves
its maximum efficiency for planets with masses in the range 0.2 and
2M{Jup}. Substellar objects with higher masses have higher
probabilities of being formed as stars. Low-mass planets and
planetesimals might be formed by core-accretion even around
low-metallicity stars.
Description:
File tableA.1.dat lists the basic properties of the full sample of
stars covered in this work.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 105 551 Basic properties of the sample of stars analysed
in this work
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Hipparcos or other identifier
16- 21 I6 --- HD ? HD number
22 A1 --- n_HD Multiplicity index on HD
24- 28 F5.2 mag Vmag ? Hipparcos V magnitude
30- 41 A12 --- SpType Hipparcos MK spectral-type
43- 47 F5.2 [Sun] [Fe/H] ? Metallicity
49- 52 F4.2 [Sun] e_[Fe/H] ? Uncertainty on metallicity
54- 57 F4.2 [Msun] Mass ? Stellar mass
59- 62 F4.2 [Msun] e_Mass ? Uncertainty on stellar mass (1)
64- 66 A3 --- Ref Reference of metallicity and mass
determination (2)
68-105 A38 --- Sample Stellar sample and notes
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Note (1): Mass uncertainties listed as 0.00 should be understood as
lower than 0.01 solar masses.
Note (2): References for stellar metallicities and masses:
1 = Maldonado et al. (2015A&A...579A..20M 2015A&A...579A..20M)
2 = Maldonado and Villaver (2016A&A...588A..98M 2016A&A...588A..98M, Cat. J/A+A/588/A98)
3 = Maldonado and Villaver (2017A&A...602A..38M 2017A&A...602A..38M)
4 = Maldonado et al. (2018A&A...612A..93M 2018A&A...612A..93M)
5 = Maldonado et al. (2015A&A...577A.132M 2015A&A...577A.132M, Cat. J/A+A/577/A132)
a = Stellar mass from Lovis and Mayor (2007A&A...472..657L 2007A&A...472..657L)
b = Bouchy et al. (2016A&A...585A..46B 2016A&A...585A..46B, Cat. J/A+A/585/A46)
c = Niedzielski et al. (2009ApJ...707..768N 2009ApJ...707..768N)
d = Stellar mass value from the NASA exoplanet archive. Specifically from the
summary of stellar information table for all stars except KOI 415 for
which we took the value from the KOI stellar properties table.
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Acknowledgements:
Jesus Maldonado, jesus.maldonado(at)inaf.it
(End) Jesus Maldonado [INAF-OAPa, Italy], Patricia Vannier [CDS] 12-Mar-2019