J/A+A/538/A100 Abundances red giants in Carina dSph (Lemasle+, 2012)
VLT/FLAMES spectroscopy of red giant branch stars in the Carina dwarf
spheroidal galaxy.
Lemasle B., Hill V., Tolstoy E., Venn K.A., Shetrone M.D., Irwin M.J.,
de Boer T.J.L., Starkenburg E., Salvadori S.
<Astron. Astrophys. 538, A100 (2012)>
=2012A&A...538A.100L 2012A&A...538A.100L
ADC_Keywords: Galaxies, nearby ; Stars, giant ; Abundances ; Radial velocities ;
Equivalent widths ; Photometry, UBVRI ; Photometry, infrared
Keywords: stars: abundances - galaxies: individual (Carina Dwarf Spheroidal) -
galaxies: evolution
Abstract:
The ages of individual Red Giant Branch stars can range from 1Gyr old
to the age of the Universe, and it is believed that the abundances of
most chemical elements in their photospheres remain unchanged with
time (those that are not affected by the first dredge-up). This means
that they trace the interstellar medium in the galaxy at the time the
star formed, and hence the chemical enrichment history of the galaxy.
Colour-Magnitude Diagram analysis has shown the Carina dwarf
spheroidal to have had an unusually episodic star formation history
and this is expected to be reflected in the abundances of different
chemical elements.
Description:
We use the VLT-FLAMES multi-fibre spectrograph in high-resolution mode
(R∼20000) to measure the abundances of several chemical elements,
including Fe, Mg, Ca and Ba, in a sample of 35 individual Red Giant
Branch stars in the Carina dwarf spheroidal galaxy. We also combine
these abundances with photometry to derive age estimates for these
stars. This allows us to determine which of two distinct star
formation episodes the stars in our sample belong to, and thus to
define the relationship between star formation and chemical enrichment
during these two episodes.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 88 98 Photometric information for our FLAMES targets
table4.dat 36 3360 List of all spectral lines, their atomic
parameters and their measured EWs for all the
35 RGB stars in the Carina dSph
table7.dat 86 35 The abundances and errors of iron and
α-elements in our sample of RGB stars
in the Carina dSph
table8.dat 73 35 The abundances and errors of iron-peak and
heavy elements in our sample of RGB stars
in the Carina dSph
table9.dat 98 8 The abundances and errors for elements that
could be measured from single lines in only
a handful of stars
--------------------------------------------------------------------------------
See also:
J/AJ/130/2677 : Stars in the Carina dSph galaxy field (Majewski+, 2005)
J/ApJ/649/201 : Velocities & Washington photometry in Carina dSph (Munoz+ 2006)
J/AJ/135/1580 : Element abundances in ten red giants of Car dSph (Koch+, 2008)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Name MKVNNNN
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 19 F5.2 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 32 F5.2 arcsec DEs Declination (J2000)
34- 39 F6.3 mag Vmag ESO-WFI V magnitude
41- 46 F6.3 mag Imag ESO-WFI I magnitude
48- 53 F6.3 mag Jmag ? ESO-SOFI J magnitude (1)
55- 60 F6.3 mag Hmag ? ESO-SOFI H magnitude (1)
62- 67 F6.3 mag Kmag ? ESO-SOFI K magnitude (1)
69- 73 F5.1 km/s HRV Heliocentric radial velocity (2)
75- 77 F3.1 km/s e_HRV rms uncertainty on HRV (2)
79- 88 A10 --- Memb Membership
--------------------------------------------------------------------------------
Note (1): From M. Gullieuszik (private communication)
Note (2): our measured radial velocities
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Star name
9- 15 F7.2 0.1nm lambda Wavelength
17- 19 A3 --- El Element
21- 25 F5.3 eV ExPot Excitation potential
27- 32 F6.3 [-] loggf Oscillator strength
34- 36 I3 0.1pm EW ?=- Equivalent width
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Star name
9- 13 F5.2 [-] [Fe1/H] Abundance [FeI/H]
15- 18 F4.2 [-] e_[Fe1/H] rms uncertainty on [FeI/H]
20- 21 I2 --- o_[Fe1/H] Number of line used for [FeI/H]
23- 27 F5.2 [-] [Fe2/H] ?=- Abundance [FeII/H]
29- 32 F4.2 [-] e_[Fe2/H] ?=- rms uncertainty on [FeII/H]
34 I1 --- o_[Fe2/H] ?=- Number of line used for [FeII/H]
36- 40 F5.2 [-] [Mg1/H] ?=- Abundance [MgI/H]
42- 45 F4.2 [-] e_[Mg1/H] ?=- rms uncertainty on [MgI/H]
47 I1 --- o_[Mg1/H] ?=- Number of line used for [MgI/H]
49- 53 F5.2 [-] [Ca1/H] ?=- Abundance [CaI/H]
55- 58 F4.2 [-] e_[Ca1/H] ?=- rms uncertainty on [CaI/H]
60 I1 --- o_[Ca1/H] ?=- Number of line used for [CaI/H]
62- 66 F5.2 [-] [Ti1/H] ?=- Abundance [TiI/H]
68- 71 F4.2 [-] e_[Ti1/H] ?=- rms uncertainty on [TiI/H]
73 I1 --- o_[Ti1/H] ?=- Number of line used for [TiI/H]
75- 79 F5.2 [-] [Ti2/H] ?=- Abundance [TiII/H]
81- 84 F4.2 [-] e_[Ti2/H] ?=- rms uncertainty on [TiII/H]
86 I1 --- o_[Ti2/H] ?=- Number of line used for [TiII/H]
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Star name
9- 13 F5.2 [-] [Fe1/H] Abundance [FeI/H]
15- 18 F4.2 [-] e_[Fe1/H] rms uncertainty on [FeI/H]
20- 21 I2 --- o_[Fe1/H] Number of line used for [FeI/H]
23- 27 F5.2 [-] [Cr1/H] ?=- Abundance [CrI/H]
29- 32 F4.2 [-] e_[Cr1/H] ?=- rms uncertainty on [CrI/H]
34 I1 --- o_[Cr1/H] ?=- Number of line used for [CrI/H]
36- 40 F5.2 [-] [Co1/H] ?=- Abundance [CoI/H]
42- 45 F4.2 [-] e_[Co1/H] ?=- rms uncertainty on [CoI/H]
47 I1 --- o_[Co1/H] ?=- Number of line used for [CoI/H]
49- 53 F5.2 [-] [Ni1/H] ?=- Abundance [NiI/H]
55- 58 F4.2 [-] e_[Ni1/H] ?=- rms uncertainty on [NiI/H]
60 I1 --- o_[Ni1/H] ?=- Number of line used for [NiI/H]
62- 66 F5.2 [-] [Ba2/H] ?=- Abundance [BaII/H]
68- 71 F4.2 [-] e_[Ba2/H] ?=- rms uncertainty on [BaII/H]
73 I1 --- o_[Ba2/H] ?=- Number of line used for [BaII/H]
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Star name
9- 13 F5.2 [-] [Na1/H] ?=- Abundance [NaI/H]
15- 18 F4.2 [-] e_[Na1/H] ?=- rms uncertainty on [NaI/H]
20 I1 --- o_[Na1/H] ?=- Number of line used for [NaI/H]
22- 26 F5.2 [-] [Si1/H] ?=- Abundance [SiI/H]
28- 31 F4.2 [-] e_[Si1/H] ?=- rms uncertainty on [SiI/H]
33 I1 --- o_[Si1/H] ?=- Number of line used for [SiI/H]
35- 39 F5.2 [-] [Sc2/H] ?=- Abundance [ScII/H]
41- 44 F4.2 [-] e_[Sc2/H] ?=- rms uncertainty on [ScII/H]
46 I1 --- o_[Sc2/H] ?=- Number of line used for [ScII/H]
48- 52 F5.2 [-] [Y2/H] ?=- Abundance [YII/H]
54- 57 F4.2 [-] e_[Y2/H] ?=- rms uncertainty on [YII/H]
59 I1 --- o_[Y2/H] ?=- Number of line used for [YII/H]
61- 65 F5.2 [-] [La2/H] ?=- Abundance [LaII/H]
67- 70 F4.2 [-] e_[La2/H] ?=- rms uncertainty on [LaII/H]
72 I1 --- o_[La2/H] ?=- Number of line used for [LaII/H]
74- 78 F5.2 [-] [Nd2/H] ?=- Abundance [NdII/H]
80- 83 F4.2 [-] e_[Nd2/H] ?=- rms uncertainty on [NdII/H]
85 I1 --- o_[Nd2/H] ?=- Number of line used for [NdII/H]
87- 91 F5.2 [-] [Eu2/H] ?=- Abundance [EuII/H]
93- 96 F4.2 [-] e_[Eu2/H] ?=- rms uncertainty on [EuII/H]
98 I1 --- o_[Eu2/H] ?=- Number of line used for [EuII/H]
--------------------------------------------------------------------------------
Acknowledgements:
Bertrand Lemasle, lemasle(at)astro.rug.nl
References:
Venn et al. Companion Paper. 2012ApJ...751..102V 2012ApJ...751..102V Cat. J/ApJ/751/102
(End) Bertrand Lemasle [Kapteyn Inst.], Patricia Vannier [CDS] 16-Dec-2011