J/A+A/589/A61 Stellar parameters and abundances for M30 (Gruyters+, 2016)
Atomic diffusion and mixing in old stars. VI: The lithium content of M30.
Gruyters P., Lind K., Richard, O. Grundahl F., Asplund M., Casagrande L.,
Charbonnel C., Milone A., Primas F., Korn A.J.
<Astron. Astrophys. 589, A61 (2016)>
=2016A&A...589A..61G 2016A&A...589A..61G (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Models, atmosphere ; Abundances ;
Photometry ; Spectroscopy
Keywords: techniques: spectroscopic - stars: abundances - stars: atmospheres -
globular cluster: individual: M30 - stars: Population II -
stars: fundamental parameters
Abstract:
The prediction of the PLANCK-constrained primordial lithium abundance
in the Universe is in discordance with the observed Li abundances in
warm Population II dwarf and subgiant stars. Among the physically best
motivated ideas, it has been suggested that this discrepancy can be
alleviated if the stars observed today had undergone photospheric
depletion of lithium.
The cause of this depletion is investigated by accurately tracing the
behaviour of the lithium abundances as a function of effective
temperature. Globular clusters are ideal laboratories for such an
abundance analysis as the relative stellar parameters of their stars
can be precisely determined.
We performed a homogeneous chemical abundance analysis of 144 stars in
the metal-poor globular cluster M30, ranging from the cluster turnoff
point to the tip of the red giant branch. Non-local thermal
equilibrium (NLTE) abundances for Li, Ca, and Fe were derived where
possible by fitting spectra obtained with VLT/FLAMES-GIRAFFE using the
quantitative-spectroscopy package SME. Stellar parameters were derived
by matching isochrones to the observed V vs V-I colour-magnitude
diagram. Independent effective temperatures were obtained from
automated profile fitting of the Balmer lines and by applying
colour-Teff calibrations to the broadband photometry.
Description:
Coordinates, photometry and derived effective temperatures for the 144
observed stars in M30. Effective temperatures where derived using
three different temperature scales: a scale based on a Victoria
isochrone (Vandenberg et al., 2014ApJ...794...72V 2014ApJ...794...72V), a scale based on the
Alonso relations (Alonso, 1996A&A...313..873A 1996A&A...313..873A, 1999A&AS..140..261A 1999A&AS..140..261A) and a
scale based on the Ramirez (2005ApJ...626..465R 2005ApJ...626..465R)
and Casagrande (2010A&A...512A..54C 2010A&A...512A..54C, Cat. J/A+A/512/A54) relations.
Additionally, the derived Hα temperatures are given.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 64 144 Photometry and effective temperatures
table5.dat 58 119 Adopted stellar parameters and abundances of
Li, Ca, Fe and Ba along with the statistical
uncertainties
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See also:
J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)
J/A+A/490/777 : Abundances of Population II stars in NGC6397 (Lind+, 2008)
J/A+A/567/A72 : Stellar parameters and abundances in NGC6752 (Gruyters+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID Star ID number
8- 9 I2 h RAh Right ascension (J2000)
11- 12 I2 min RAm Right ascension (J2000)
14- 18 F5.2 s RAs Right ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 31 F5.2 arcsec DEs Declination (J2000)
33- 38 F6.3 mag Vmag Johnson V magnitude
40- 44 F5.3 mag V-I V-I colour index
46- 49 I4 K TeffVic Effective temperature based on Victoria
isochrone (Vandenberg et al.,
2014ApJ...794...72V 2014ApJ...794...72V)
51- 54 I4 K TeffRMC Effective temperature based on
Ramirez (2005ApJ...626..465R 2005ApJ...626..465R) and
Casagrande (2010, Cat. J/A+A/512/A54)
56- 59 I4 K TeffAl Effective temperature based on Alonso
(1996A&A...313..873A 1996A&A...313..873A+1999A&AS..140..261A 1999A&AS..140..261A)
relations
61- 64 I4 K TeffHa Effective temperature based on Hα profile
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID Star ID number
8- 11 I4 K Teff Effective temperature
13- 16 F4.2 [cm/s2] logg Surface gravity
18- 22 F5.2 --- A(Li) ? Lithium abundance (1)
24- 27 F4.2 --- e_A(Li) Uncertainty in Li abundance (2)
29- 32 F4.2 --- A(Ca) Calcium abundance (1)
34- 37 F4.2 --- e_A(Ca) Uncertainty in Ca abundance (2)
39- 42 F4.2 --- A(Fe) Iron abundance (1)
44- 47 F4.2 --- e_A(Fe) Uncertainty in Fe abundance (2)
49- 53 F5.2 --- A(Ba) Barium abundance (1)
55- 58 F4.2 --- e_A(Ba) Uncertainty in Ba abundance (2)
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Note (1): Where A(El)=logN(El)/N(H) + 12.
Note (2): Uncertainties are given by statistical errors. Only the results for
the stars for which abundances could be derived sufficiently accurate are
given in this table.
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Acknowledgements:
Pieter Gruyters, pieter.gruyters(at)gmail.com
References:
Korn et al., Paper I 2007ApJ...671..402K 2007ApJ...671..402K
Lind et al., Paper II 2008A&A...490..777L 2008A&A...490..777L, Cat. J/A+A/490/777
Nordlander et al., Paper III 2012ApJ...753...48N 2012ApJ...753...48N
Gruyters et al., Paper IV 2013A&A...555A..31G 2013A&A...555A..31G
Gruyters et al., Paper V 2014A&A...567A..72G 2014A&A...567A..72G, Cat. J/A+A/567/A72
(End) Pieter Gruyters [LU, Sweden], Patricia Vannier [CDS] 31-Mar-2016