J/A+A/499/737 Abundances of microlensed dwarf and subgiant stars (Bensby+, 2009)
Chemical evolution of the Galactic bulge as traced by microlensed dwarf and
subgiant stars. Detailed abundance analysis of OGLE-2008-BLG-209S.
Bensby T., Johnson J.A., Cohen J., Feltzing S., Udalski A., Gould A.,
Huang W., Thompson I., Simmerer J., Aden D.
<Astron. Astrophys. 499, 737 (2009)>
=2009A&A...499..737B 2009A&A...499..737B
ADC_Keywords: Gravitational lensing ; Abundances ; Equivalent widths
Keywords: gravitational lensing - Galaxy: bulge - Galaxy: formation -
Galaxy: evolution - stars: abundances - stars: fundamental parameters
Abstract:
We present a detailed elemental abundance analysis of
OGLE-2008-BLG-209S, the source star of a new microlensing event
towards the Bulge, for which we obtained a high-resolution spectrum
with the MIKE spectrograph on the Magellan Clay telescope. We have
performed four different analyses of OGLE-2008-BLG-209S. One method is
identical to the one used for a large comparison sample of F and G
dwarf stars, mainly thin and thick disc stars, in the Solar
neighbourhood. We have also re-analysed three previous microlensed
dwarf stars OGLE-2006-BLG-265S, MOA-2006-BLG-099S, and
OGLE-2007-BLG-349S with the same method. This homogeneous data set,
although small, enables a direct comparison between the different
stellar populations.
Description:
For each spectral line we give the log g value, lower excitation
potential, measured equivalent widths, derived absolute abundance,
abundance normalised to the Sun (on a line-by-line basis) ([X/H]).
Objects:
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RA (2000) DE Designation(s)
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18 04 49.9 -29 42 33 Star 209 = EWS 2008-BUL-209
18 07 18.9 -27 47 43 Star 265 = EWS 2006-BUL-265
17 54 11.0 -35 13 38 Star 099 = MOA 2006-BLG-99
18 05 24.4 -26 25 19 Star 349 = EWS 2007-BUL-349
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 106 460 Equivalent width measurements and elemental
abundances for OGLE-2008-BLG-209S,
OGLE-2006-BLG-265S, MOA-2006-BLG-099S, and
OGLE-2007-BLG-349S
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See also:
J/ApJ/655/L33 : High-resolution spectrum of OGLE-2006-BLG-265 (Johnson+, 2007)
J/A+A/512/A41 : Abundances of microlensed stars in the Bulge (Bensby+, 2010)
J/A+A/533/A134 : Abundances of microlensed stars in the Bulge (Bensby+, 2011)
ftp://sirius.astrouw.edu.pl/ogle/ogle3/ews/ : OGLE EWS Home Page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- El Element
4 I1 --- Ion Neutral or ionised element
6- 13 F8.3 0.1nm lambda Wavelength
15- 19 F5.2 --- loggf Oscillator strength
21- 25 F5.2 eV EP Lower excitation potential
27- 31 F5.1 0.1pm EWsun Sun measured equivalent width
33- 36 F4.2 --- A(Sun) Sun absolute abundance (log scale, A(H)=12)
38 I1 --- f_A(Sun) [0,1] 0 if line not directly measured (1)
40- 44 F5.1 0.1pm EW209 ? OGLE-2009-BLG-209S Measured equivalent width
46- 49 F4.2 --- A(209) ? OGLE-2009-BLG-209S Absolute abundance
51- 55 F5.2 [Sun] [X/H]209 ? OGLE-2009-BLG-209S Normalised abundance
57- 61 F5.1 0.1pm EW265 ? OGLE-2006-BLG-265S Measured equivalent width
63- 66 F4.2 --- A(265) ? OGLE-2006-BLG-265S Absolute abundance
68- 72 F5.2 [Sun] [X/H]265 ? OGLE-2006-BLG-265S Normalised abundance
74- 78 F5.1 0.1pm EW099 ? MOA-2006-BLG-099S Measured equivalent width
80- 83 F4.2 --- A(099) ? MOA-2006-BLG-099S Absolute abundance
85- 89 F5.2 [Sun] [X/H]099 ? MOA-2006-BLG-099S Normalised abundance
91- 95 F5.1 0.1pm EW349 ? OGLE-2007-BLG-349S Measured equivalent with
97-100 F4.2 --- A(349) ? OGLE-2007-BLG-349S Absolute abundance
102-106 F5.2 [Sun] [X/H]349 ? OGLE-2007-BLG-349S Normalised abundance
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Note (1): The value 0 indicates a line not measured in the solar spectrum
and that the abundance given (and used in the normalisation) for that
line is the average abundance based on all the other lines, that could
be measured in the solar spectrum, of the same species.
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Acknowledgements:
Thomas Bensby, tbensby(at)eso.org
References:
Bensby et al., Paper II 2010A&A...512A..41B 2010A&A...512A..41B, Cat. J/A+A/512/A41
Bensby et al., Paper III 2010A&A...521L..57B 2010A&A...521L..57B
Bensby et al., Paper IV 2011A&A...533A.134B 2011A&A...533A.134B, Cat. J/A+A/533/A134
(End) Thomas Bensby [ESO, Chile], Patricia Vannier [CDS] 03-Apr-2009