J/MNRAS/434/358 4 Galactic globular clusters Fe line depths (Sakari+, 2013)
Spectrum syntheses of high-resolution integrated light spectra of Galactic
globular clusters.
Sakari C.M., Shetrone M., Venn K., McWilliam A., Dotter A.
<Mon. Not. R. Astron. Soc., 434, 358-386 (2013)>
=2013MNRAS.434..358S 2013MNRAS.434..358S
ADC_Keywords: Clusters, globular ;
Keywords: techniques: spectroscopic - globular clusters: individual: 47 Tuc -
globular clusters: individual: M3 -
globular clusters: individual: M13 -
globular clusters: individual: NGC 7006 -
globular clusters: individual: M15
Abstract:
Spectrum syntheses for three elements (Mg, Na and Eu) in
high-resolution integrated light spectra of the Galactic globular
clusters 47 Tuc, M3, M13, NGC 7006 and M15 are presented, along with
calibration syntheses of the solar and Arcturus spectra. Iron
abundances in the target clusters are also derived from integrated
light equivalent width analyses. Line profiles in the spectra of these
five globular clusters are well fitted after careful consideration of
the atomic and molecular spectral features, providing levels of
precision that are better than equivalent width analyses of the same
integrated light spectra, and that are comparable to the precision in
individual stellar analyses. The integrated light abundances from the
5528 and 5711Å MgI lines, the 6154 and 6160Å NaI lines, and the
6645Å EuII line fall within the observed ranges from individual
stars; however, these integrated light abundances do not always agree
with the average literature abundances. Tests with the second
parameter clusters M3, M13 and NGC 7006 show that assuming an
incorrect horizontal branch morphology is likely to have only a small
(≲0.06dex) effect on these Mg, Na and Eu abundances. These tests
therefore show that integrated light spectrum syntheses can be applied
to unresolved globular clusters over a wide range of metallicities and
horizontal branch morphologies. Such high precision in integrated
light spectrum syntheses is valuable for interpreting the chemical
abundances of globular cluster systems around other galaxies.
Description:
The 47 Tuc spectrum was kindly provided by R. Bernstein and A.
McWilliam. It is the same spectrum analysed in McWillian & Bernstein
(2008ApJ...684..326M 2008ApJ...684..326M); details on the observations and data reduction
can be found there.
The other spectra were observed with the High Resolution Spectrograph
(HRS) on the Hobby-Eberly Telescope (HET) at McDonald Observatory in
Fort Davis, Texas, in 2011 and 2012.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
objects.dat 38 6 List of studied objects
table8.dat 69 130 The Fe line list
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Byte-by-byte Description of file: objects.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Simbad name of source
10- 11 I2 h RAh Simbad right ascension (J2000.0)
13- 14 I2 min RAm Simbad right ascension (J2000.0)
16- 20 F5.2 s RAs Simbad right ascension (J2000.0)
22 A1 --- DE- Simbad declination sign (J2000.0)
23- 24 I2 deg DEd Simbad declination (J2000.0)
26- 27 I2 arcmin DEm Simbad declination (J2000.0)
29- 32 F4.1 arcsec DEs Simbad declination (J2000.0)
34- 38 A5 --- Sname Short name
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 0.1nm lambda Spectral line wavelength λ
10- 13 A4 --- El Element and ionization state (FeI or FeII)
15- 19 F5.3 eV EP Excitation Potential
21- 27 F7.3 [-] loggf Oscillator strength
29- 33 F5.1 10-13m W(Sun) ?=- Equivalent width for Sun (mÅ)
35- 39 F5.1 10-13m W(aBoo) ?=- Equivalent width for Arcturus (mÅ)
41- 45 F5.1 10-13m W(47Tuc) ?=- Equivalent width for 47 Tuc (mÅ)
47- 51 F5.1 10-13m W(M3) ?=- Equivalent width for M3 (mÅ)
53- 57 F5.1 10-13m W(M13) ?=- Equivalent width for M13 (mÅ)
59- 63 F5.1 10-13m W(N7006) ?=- Equivalent width for NGC 7006 (mÅ)
65- 69 F5.1 10-13m W(M15) ?=- Equivalent width for M15 (mÅ)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Jan-2015