J/MNRAS/435/952 Lick indices for 51 stars (Sansom+, 2013)
Tests of model predictions for the responses of stellar spectra and
absorption-line indices to element abundance variations.
Sansom A.E., de Castro Milone A., Vazdekis A., Sanchez-Blazquez P.
<Mon. Not. R. Astron. Soc., 435, 952-974 (2013)>
=2013MNRAS.435..952S 2013MNRAS.435..952S
ADC_Keywords: Spectroscopy ; Abundances
Keywords: techniques: spectroscopic - stars: abundances - stars: atmospheres -
galaxies: abundances - galaxies: stellar content
Abstract:
A method that is widely used to analyse stellar populations in
galaxies is to apply the theoretically derived responses of stellar
spectra and line indices to element abundance variations, which are
hereafter referred to as response functions. These are applied in a
differential way, to base models, in order to generate spectra or
indices with different abundance patterns. In this paper, sets of such
response functions for three different stellar evolutionary stages are
tested with new empirical [Mg/Fe] abundance data for the
medium-resolution Isaac Newton Telescope library of empirical spectra
(MILES). Recent theoretical models and observations are used to
investigate the effects of [Fe/H], [Mg/H] and overall [Z/H] on
spectra, via ratios of spectra for similar stars. The global effects
of changes in abundance patterns are investigated empirically through
direct comparisons of similar stars from MILES, highlighting the
impact of abundance effects in the blue part of the spectrum,
particularly for lower temperature stars. It is found that the
relative behaviour of iron-sensitive line indices are generally well
predicted by response functions, whereas Balmer line indices are not.
Other indices tend to show large scatter about the predicted mean
relations. Implications for element abundance and age studies in
stellar populations are discussed and ways forward are suggested to
improve the match with the behaviour of spectra and line-strength
indices observed in real stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 220 51 Tables of data for stars corresponding to the
base model Teff and log(g) values in Korn et al.,
2005A&A...438..685K 2005A&A...438..685K, for cool dwarfs, turn-off
stars and cool giants, from a 5Gyr old population
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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- 2 A2 --- Mod Model: CD, TO or CG (1)
4- 5 I2 --- No [1/31] Sequential number within the model
8- 16 A9 --- Name Star name
18- 21 I4 K Teff [4159/6298] Effective temperature
23- 26 F4.2 [cm/s2] logg [1.7/4.7] Surface gravity
28- 33 F6.3 [Sun] [Fe/H] [-2.9/0.5] Metallicity
35- 40 F6.3 [Sun] [Mg/Fe] [-0.4/0.6] Abundance [Mg/Fe]
42- 44 I3 --- M MILES (Medium-resolution Isaac Newton
Telescope Library) star identifier
46- 51 F6.3 0.1nm HdA HδA Lick index
53- 58 F6.3 0.1nm HdF HδF Lick index
60- 65 F6.3 0.1nm CN1 CN1 Lick index
67- 72 F6.3 0.1nm CN2 CN_2 Lick index
74- 79 F6.3 0.1nm Ca4227 Ca4227 Lick index
81- 86 F6.3 0.1nm G4300 G4300 Lick index
88- 94 F7.3 0.1nm HgA HγA Lick index
96-101 F6.3 0.1nm HgF HγF Lick index
103-108 F6.3 0.1nm Fe4383 Fe4383 Lick index
110-115 F6.3 0.1nm Ca4455 Ca4455 Lick index
117-122 F6.3 0.1nm Fe4531 Fe4531 Lick index
124-129 F6.3 0.1nm C2-4668 C24668 Lick index
131-136 F6.3 0.1nm Hb Hβ Lick index
138-143 F6.3 0.1nm Fe5015 Fe5051 Lick index
145-150 F6.3 mag Mg1 Mg1 Lick index
152-157 F6.3 mag Mg2 Mg2 Lick index
159-164 F6.3 0.1nm Mgb Mgb Lick index
166-171 F6.3 0.1nm Fe5270 Fe5270 Lick index
173-178 F6.3 0.1nm Fe5335 Fe5335 Lick index
180-185 F6.3 0.1nm Fe5406 Fe5406 Lick index
187-192 F6.3 0.1nm Fe5709 Fe5709 Lick index
194-199 F6.3 0.1nm Fe5782 Fe5782 Lick index
201-206 F6.3 0.1nm NaD NaD Lick index
208-213 F6.3 0.1nm TiO1 TiO1 Lick index
215-220 F6.3 0.1nm TiO2 TiO2 Lick index
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Note (1): Models as follows:
CD = cool dwarf. Model:(Teff=4575.0,logg=4.60)
TO = turn-off stars. Model:(Teff=6200.0,logg=4.10)
CG = cool giant. Model:(Teff=4255.0,logg=1.90)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 22-Sep-2014