J/ApJ/813/97 M62 (NGC 6266) giant branch stars abundances (Lapenna+, 2015)
Chemical analysis of asymptotic giant branch stars in M62.
Lapenna E., Mucciarelli A., Ferraro F.R., Origlia L., Lanzoni B.,
Massari D., Dalessandro E.
<Astrophys. J., 813, 97 (2015)>
=2015ApJ...813...97L 2015ApJ...813...97L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Abundances ; Radial velocities ;
Stars, giant
Keywords: globular clusters: individual: M62; techniques: spectroscopic
stars: abundances; stars: AGB and post-AGB; stars: late-type
Abstract:
We have collected UVES-FLAMES high-resolution spectra for a sample of
6 asymptotic giant branch (AGB) and 13 red giant branch (RGB) stars in
the Galactic globular cluster (GC) M62 (NGC 6266). Here we present the
detailed abundance analysis of iron, titanium, and light elements (O,
Na, Mg, and Al). For the majority (five out of six) of the AGB
targets, we find that the abundances of both iron and titanium
determined from neutral lines are significantly underestimated with
respect to those obtained from ionized features, the latter being,
instead, in agreement with those measured for the RGB targets. This is
similar to recent findings in other clusters and may suggest the
presence of nonlocal thermodynamic equilibrium (NLTE) effects. In the
O-Na, Al-Mg, and Na-Al planes, the RGB stars show the typical
correlations observed for GC stars. Instead, all the AGB targets are
clumped in the regions where first-generation stars are expected to
lie, similar to what was recently found for the AGB population of
NGC6752. While the sodium and aluminum abundances could be
underestimated as a consequence of the NLTE bias affecting iron and
titanium, the oxygen line used does not suffer from the same effects,
and the lack of O-poor AGB stars therefore is a solid result. We can
thus conclude that none of the investigated AGB stars belongs to the
second stellar generation of M62. We also find an RGB star with
extremely high sodium abundance ([Na/Fe]=+1.08dex).
Description:
We have observed a sample of 19 giant stars in the GC M62 by using the
UVES-FLAMES at VLT spectrograph within the Large Program 193.D-0232
(PI: Ferraro); with a spectral coverage between 4800-6800Å and
R∼40000 during the nights of 2014 April 16 and June 2, 3, and 19.
The target stars have been selected from the photometric catalog of
Beccari et al. (2006AJ....131.2551B 2006AJ....131.2551B), obtained from HST WFPC2
observations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 70 19 Photometric properties and radial velocities of
the RGB and AGB samples
table2.dat 73 282 Wavelength, element, oscillator strength, excitation
potential, and reference source of adopted lines
table3.dat 75 19 Atmospheric parameters and iron and titanium
abundances of the measured RGB and AGB stars
table4.dat 90 19 OI, NaI, MgI, AlI, TiI, and TiII abundances of the
RGB and AGB samples
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See also:
J/ApJ/801/69 : Iron EWs for NGC3201 giant star members (Mucciarelli+, 2015)
J/A+A/564/A60 : NGC 4833 Na-O measured with FLAMES (Carretta+, 2014)
J/ApJS/208/27 : Sun and HD 84937 TiII log(gf) and abundances (Wood+, 2013)
J/ApJ/775/L27 : Chemical abundances in a metal-poor RGB star (Johnson+, 2013)
J/A+A/557/A128 : Stellar [Fe/H] and [Na/H] in NGC6752 (Carretta, 2013)
J/other/Nat/498.198 : Na abundances in NGC6752 (Campbell+, 2013)
J/AJ/143/70 : Differential reddening in MW globulars (Alonso-Garcia+, 2012)
J/ApJ/754/L38 : Abundances & radial velocities of M13 giants (Johnson+, 2012)
J/ApJ/750/91 : Metallicities of old stellar systems (Chattopadhyay+, 2012)
J/A+A/534/A80 : Bulge clump giant metallicity in Baade's window (Hill+, 2011)
J/ApJ/731/64 : Spectroscopy of 300 RGBs in ω Cen (Marino+, 2011)
J/MNRAS/405/839 : Spectroscopic obs. of globular clusters (Sharina+, 2010)
J/A+A/505/139 : Abundances of red giants in 17 GCs (Carretta+, 2009)
J/A+A/505/117 : Abundances of red giants in 15 GCs (Carretta+, 2009)
J/ApJ/695/L134 : Chemical anomalies in old LMC clusters (Mucciarelli+, 2009)
J/A+A/486/177 : Bulge field stars from FLAMES-GIRAFFE sp. (Zoccali+, 2008)
J/A+A/354/169 : Metal-poor field stars abundances (Gratton+, 2000)
J/A+A/350/955 : Atmospheric param. in metal-poor stars. II (Gratton+, 1999)
J/A+A/340/300 : Fe II oscillator strengths (Raassen+ 1998)
J/A+A/324/505 : Core velocity dispersions of globular clusters (Dubath+ 1997)
J/MNRAS/272/391 : Globular clusters in the Magellanic Clouds (Ferraro+, 1995)
http://wwwuser.oats.inaf.it/castelli/linelists.html : Line lists
http://www.nist.gov/pml/data/asd.cfm : NIST atomic spectra database
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [50/158] Identification number
5- 15 F11.7 deg RAdeg Right ascension (J2000)
17- 27 F11.7 deg DEdeg Declination (J2000)
29- 34 F6.3 mag Umag [17.1/17.9] U-band magnitude
36- 41 F6.3 mag Vmag [14/15.2] V-band magnitude
43- 48 F6.3 mag U0mag [14.3/15.1] U-band magnitude reddening corrected
50- 55 F6.3 mag V0mag [12.1/13.5] V-band magnitude reddening corrected
57- 63 F7.2 km/s HRV [-110/-53.4] Heliocentric radial velocity
65- 68 F4.2 km/s e_HRV [0.04/0.09] HRV uncertainty
70 A1 --- Type Type of star (R=RGB, A=AGB)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 0.1nm lambda [4806.3/6750.2] Wavelength; Angstroms
10- 13 A4 --- Ion Ion identifier
15- 20 F6.3 [-] log(gf) [-9.8/0.7] Log oscillator strength
22- 26 F5.3 eV ExPot [0/5.2] Excitation potential
28- 53 A26 --- Ref Reference (1)
55- 73 A19 --- BibCode Bibcode of Reference if relevant
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Note (1): Abbreviation as follows:
K = Oscillator strengths (OS) from the R.L. Kurucz on-line database
of observed and predicted atomic transitions (see
http://kurucz.harvard.edu/).
NIST = OS from NIST database (see http://www.nist.gov/pml/data/asd.cfm).
S = OS from solar analysis by F. Castelli (see
http://wwwuser.oats.inaf.it/castelli/linelists.html).
S* = For AlI lines we derived astrophysical oscillator strengths by using
the solar flux spectra of Neckel & Labs (1984SoPh...90..205N 1984SoPh...90..205N)
and the model atmosphere for the Sun computed by F. Castelli
(http://wwwuser.oats.inaf.it/castelli/sun/ap00t5777g44377k1odfnew.dat)
adopting the solar abundances of
Grevesse & Sauval (1998SSRv...85..161G 1998SSRv...85..161G).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [50/158] Identification number (1)
5- 8 I4 K Teff [4215/4840] Spectroscopic effective temperature
10- 13 F4.2 [cm/s2] logg [0.8/1.6] Surface gravity
15- 18 F4.2 km/s Vturb [1.3/1.8] Microturbulent velocity
20- 24 F5.2 [Sun] [FeI/H] [-1.3/-1] Abundance of [FeI/H]
26- 29 F4.2 [Sun] e_[FeI/H] [0.01] [FeI/H] internal uncertainty
31- 33 I3 --- nFeI [102/146] Number of FeI lines used
35- 39 F5.2 [Sun] [FeII/H] [-1.2/-0.9] Abundance of [FeII/H]
41- 44 F4.2 [Sun] e_[FeII/H] [0.01/0.04] [FeII/H] internal uncertainty
46- 47 I2 --- nFeII [7/12] Number of FeII lines used
49- 53 F5.2 [Sun] [TiI/H] [-1.2/-0.7] Abundance of [TiI/H]
55- 58 F4.2 [Sun] e_[TiI/H] [0.01/0.03] [TiI/H] internal uncertainty
60- 61 I2 --- nTiI [27/63] Number of TiI lines used
63- 67 F5.2 [Sun] [TiII/H] [-1.1/-0.8] Abundance of [TiII/H]
69- 72 F4.2 [Sun] e_[TiII/H] [0.03/0.07] [TiII/H] internal uncertainty
74- 75 I2 --- nTiII [6/15] Number of TiII lines used
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Note (1): For all of the stars a global metallicity of [M/H]=-1.0dex has been
assumed for the model atmosphere. The adopted solar values are from
Grevesse & Sauval (1998SSRv...85..161G 1998SSRv...85..161G) unless stated otherwise.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [50/158] Identification number
5 A1 --- l_[OI/FeII] Upper limit flag on [OI/FeII]
7- 11 F5.2 [Sun] [OI/FeII] [-0.4/0.4] Abundance of [OI/FeII] (2)
13- 16 F4.2 [Sun] e_[OI/FeII] [0.04/0.09]? [OI/FeII] uncertainty
18- 22 F5.2 [Sun] [NaI/FeI]L [-0.2/1.1] LTE abundance of [NaI/FeI] (3)
24- 27 F4.2 [Sun] e_[NaI/FeI]L [0.04/0.2] [NaI/FeI]L uncertainty
29- 33 F5.2 [Sun] [NaI/FeI]N [-0.08/1.1] NLTE abundance of [NaI/FeI] (3)
35- 38 F4.2 [Sun] e_[NaI/FeI]N [0.02/0.2] [NaI/FeI]N uncertainty
40 I1 --- nNa [3/4] Number of NaI lines used
42- 45 F4.2 [Sun] [MgI/FeI] [0.3/0.6] Abundance of [MgI/FeI]
47- 50 F4.2 [Sun] e_[MgI/FeI] [0.01/0.09] [MgI/FeI] uncertainty
52 I1 --- nMg [2/3] Number of MgI lines used
54- 57 F4.2 [Sun] [AlI/FeI] [0.1/1.2] Abundance of [AlI/FeI]
59- 62 F4.2 [Sun] e_[AlI/FeI] [0/0.07] [AlI/FeI] uncertainty
64 I1 --- nAl [1/2] Number of AlI lines used
66- 69 F4.2 [Sun] [TiI/FeI] [0.06/0.4] Abundance of [TiI/FeI]
71- 74 F4.2 [Sun] e_[TiI/FeI] [0.01/0.04] [TiI/FeI] uncertainty
76- 77 I2 --- nTiI [27/63] Number of TiI lines used
79- 82 F4.2 [Sun] [TiII/FeII] [0.05/0.3] Abundance of [TiII/FeII]
84- 87 F4.2 [Sun] e_[TiII/FeII] [0.03/0.08] [TiII/FeII] uncertainty
89- 90 I2 --- nTiII [6/15] Number of TiII lines used
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Note (2): The oxygen abundance has been derived from the 6300.3Å [OI] line.
The reference solar values are taken from Caffau et al.
(2011SoPh..268..255C 2011SoPh..268..255C) for the oxygen.
Note (3): The abundances of sodium have been reported without and with
nonlocal thermodynamic equilibrium (NLTE) corrections computed
following Gratton et al. 1999, J/A+A/350/955.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Feb-2016