J/A+A/608/A100 CMD and mass distribution of Ba stars (Escorza+, 2017)
Hertzsprung-Russell diagram and mass distribution of barium stars.
Escorza A., Boffin H.M.J., Jorissen A., Van Eck S., Siess L.,
Van Winckel H., Karinkuzhi D., Shetye S., Pourbaix D.
<Astron. Astrophys. 608, A100 (2017)>
=2017A&A...608A.100E 2017A&A...608A.100E (SIMBAD/NED BibCode)
ADC_Keywords: Stars, barium; Stars, giant; HR diagrams; Stars, masses
Keywords: Binaries: general - stars: late-type - stars: chemically peculiar
Abstract:
With the availability of parallaxes provided by the Tycho-Gaia
Astrometric Solution, it is possible to construct the
Hertzsprung-Russell diagram (HRD) of barium and related stars with
unprecedented accuracy. A direct result from the derived HRD is that
subgiant CH stars occupy the same region as barium dwarfs, contrary to
what their designations imply. By comparing the position of barium
stars in the HRD with STAREVOL evolutionary tracks, it is possible to
evaluate their masses, provided the metallicity is known. We used an
average metallicity [Fe/H]=-0.25 and derived the mass distribution
of barium giants. The distribution peaks around 2.5M☉, with a tail
at higher masses up to 4.5M☉. This peak is seen as well in the
mass distribution of a sample of normal K and M giants used for
comparison and is associated with stars located in the red clump. When
we compare these mass distributions, we see a deficit of low-mass
(1-2M☉) barium giants. This is probably because low-mass stars
reach large radii at the tip of the red giant branch, which may have
resulted in an early binary interaction. Among barium giants, the
high-mass tail is however dominated by stars with a barium index
(based on a visual inspection of the barium spectral line) less than
unity, i.e., with a very moderate barium line strength. We believe
that these stars are not genuine barium giants, but rather bright
giants (or supergiants) where the barium lines are strengthened
because of a positive luminosity effect. Moreover, contrary to
previous claims, we do not see differences between the mass
distributions of mild and strong barium giants.
Description:
This catalogue contains the effective temperatures and luminosities
obtained for a sample of barium and related stars by an SED fitting
method and using MARCS models with three different metallicities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 262 437 Effective temperatures and luminosities obtained
for a sample of barium and related stars
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/A+A/326/722 : HIPPARCOS Ba stars (Mennessier+ 1997)
J/A+A/372/245 : Infrared properties of barium stars (Chen+, 2001)
J/A+A/454/895 : Abundances of 26 barium stars. I. (Allen+, 2006)
J/A+A/454/917 : Abundances of 26 barium stars. II. (Allen+, 2006)
J/A+A/525/A63 : Abundances in Ba stars (Allen+, 2011)
J/AZh/79/909 : Chemical abundances in barium stars (Boyarchuk+, 2002)
J/AZh/80/704 : Studies of classical barium stars (Antipova+, 2003)
J/MNRAS/459/4299 : Barium stars abundances and kinematics (de Castro+, 2016)
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 Name of the star
16- 27 F12.8 deg RAdeg Right ascension (J2000)
29- 40 F12.8 deg DEdeg Declination (J2000)
42- 46 A5 --- Type Star type
48- 55 F8.2 d Per ? Orbital period (1)
57- 61 F5.3 --- e ? Orbital eccentricity (1)
63- 67 F5.2 [Sun] [Fe/H] ? Metallicity with respect to solar
69- 90 A22 --- r_[Fe/H] Reference for [Fe/H] (2)
92- 96 F5.1 mas plx Parallax
98-100 F3.1 mas e_plx Error on the parallax
102-130 A29 --- r_plx Reference for the parallax (3)
132-135 I4 K b_T(0.0) Lower limit of Teff for grid with [Fe/H]=0.0
137-140 I4 K T(0.0) Effective temperature for grid with [Fe/H]=0.0
142-145 I4 K B_T(0.0) Upper limit of Teff for grid with [Fe/H]=0.0
147-154 F8.3 Lsun b_L(0.0) Lower limit of luminosity for grid
with [Fe/H]=0.0
156-164 F9.3 Lsun L(0.0) Luminosity for grid with [Fe/H]=0.0
166-174 F9.3 Lsun B_L(0.0) Upper limit of luminosity for grid
with [Fe/H]=0.0
176-179 I4 K b_T(-0.25) Lower limit of Teff for grid with [Fe/H]=-0.25
181-184 I4 K T(-0.25) Effective temperature for grid
with [Fe/H]=-0.25
186-189 I4 K B_T(-0.25) Upper limit of Teff for grid with [Fe/H]=-0.25
191-198 F8.3 Lsun b_L(-0.25) Lower limit of luminosity for grid
with [Fe/H]=-0.25
200-208 F9.3 Lsun L(-0.25) Luminosity for grid with [Fe/H]=-0.25
210-218 F9.3 Lsun B_L(-0.25) Upper limit of luminosity for grid
with [Fe/H]=-0.25
220-223 I4 K b_T(-0.5) Lower limit of Teff for grid with [Fe/H]=-0.5
225-228 I4 K T(-0.5) Effective temperature for grid
with [Fe/H]=-0.5
230-233 I4 K B_T(-0.5) Upper limit of Teff for grid with [Fe/H]=-0.5
235-242 F8.3 Lsun b_L(-0.5) Lower limit of luminosity for grid
with [Fe/H]=-0.5
244-252 F9.3 Lsun L(-0.5) Luminosity for grid with [Fe/H]=-0.5
254-262 F9.3 Lsun B_L(-0.5) Upper limit of luminosity for grid
with [Fe/H]=-0.5
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Note (1): Orbital periods and eccentricities are determined by Jorissen et al.
(1998A&A...332..877J 1998A&A...332..877J) and Jorissen et al. (2017, in preparation) for the giants
and by Escorza et al. (2017, in preparation) for the main sequence
and subgiant stars.
Note (2): Karinkuzhi for Karinkuzhi et al. (2017, in prep).
Note (3): References as follows:
Hipparcos (ESA, 1997) = HIP, 1997HIP...C......0E 1997HIP...C......0E, Cat. I/239
Pourbaix & Jorissen (2000) = Pourbaix & Jorissen, 2000A&AS..145..161P 2000A&AS..145..161P
TGAS (Lindegren et al., 2016) = TGAS, 2016A&A...595A...1G 2016A&A...595A...1G, Cat. I/337
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Acknowledgements:
Ana Escorza, ana.escorza(at)kuleuven.be
(End) Ana Escorza [KU Leuven], Patricia Vannier [CDS] 04-Oct-2017