J/ApJ/887/91 Equivalent widths of giants in the GC NGC3201 (Marino+, 2019)
Chemical abundances along the 1G sequence of the chromosome maps: the globular
cluster NGC 3201.
Marino A.F., Milone A.P., Sills A., Yong D., Renzini A., Bedin L.R.,
Cordoni G., D'Antona F., Jerjen H., Karakas A., Lagioia E., Piotto G.,
Tailo M.
<Astrophys. J., 887, 91-91 (2019)>
=2019ApJ...887...91M 2019ApJ...887...91M (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular; Stars, giant; Equivalent widths;
Radial velocities; Photometry, UBV; Ultraviolet; Abundances
Keywords: Population II stars; Stellar populations; Globular star clusters
Hertzsprung Russell diagram; Chemical abundances
Abstract:
The Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular
Clusters (GCs) has investigated multiple stellar populations by means
of the "chromosome map" (ChM) diagnostic tool that maximizes the
separation between stars with different chemical compositions. One of
the most challenging features revealed by ChM analysis is the apparent
inhomogeneity among stars belonging to the first population, a
phenomenon largely attributed to He variations. However, this
explanation is not supported by uniformity in the p-capture elements
of these stars. The HST survey has revealed that the GC NGC 3201 shows
exceptionally wide coverage in the ΔF275W,F814W parameter of
the ChM. We present a chemical abundance analysis of 24 elements in 18
giants belonging to the first population of this GC and having a wide
range in ΔF275W,F814W. As far as the p-capture elements are
concerned, the chemical abundances are typical of first-generation
(1G) stars, as expected from the location of our targets in the ChM.
Based on radial velocities and chemical abundance arguments, we find
that the three stars with the lowest ΔF275W,F814W values are
binary candidates. This suggests that at least those stars could be
explained with binarity. These results are consistent with evidence
inferred from multiband photometry that evolved blue stragglers (BSs)
populate the bluest part of the 1G sequence in the ChM. The remaining
15 spectroscopic targets show a small range in the overall metallicity
by ∼0.10dex, with stars at higher ΔF275W,F814W values having
higher absolute abundances. We suggest that a small variation in
metals and binarity governs the color spread of the 1G in the ChM and
that evolved BSs contribute to the bluest tail of the 1G sequence.
Description:
The photometric data used in this study come from the HST UV Legacy
Survey, which investigated multiple stellar populations in GCs
(GO-13297; Piotto+ 2015AJ....149...91P 2015AJ....149...91P). See Section 2.1.
Our spectroscopic data have been acquired using the FLAMES Ultraviolet
and Visual Echelle Spectrograph (FLAMES-UVES) on the European Southern
Observatory's (ESO) Very Large Telescope (VLT) through program
0101.D-0113(A). The observations were taken in the standard RED580
setup, which has a wavelength coverage of 4726-6835Å and a
resolution R∼47000.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 73 18 List of observed giants in NGC 3201
table2.dat 61 18 Adopted atmospheric parameters derived from
spectroscopy and the corresponding FeI and FeII
abundances
table3.dat 36 4375 Atomic data and equivalent widths for program stars
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See also:
J/AJ/133/1658 : ACS survey of galactic globular clusters (Sarajedini+, 2007)
J/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008)
J/A+A/497/371 : UBVI photometry of NGC 3201 (Kravtsov+, 2009)
J/ApJ/696/797 : Evolution and yields of low-mass AGB stars (Cristallo+, 2009)
J/A+A/503/541 : Neutral Li in late-type stars (Lind+, 2009)
J/A+A/503/545 : Equivalent widths of Li, Na, Fe, Ca in NGC 6397 (Lind+, 2009)
J/A+A/505/117 : Abundances of red giants in 15 GCs (Carretta+, 2009)
J/ApJ/711/350 : Metal-poor giant Boo-1137 abundances (Norris+, 2010)
J/AcA/62/357 : Proper motions in 6 globular clusters (Zloczewski+, 2012)
J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)
J/ApJ/797/44 : Evolution and nucleosynthesis of AGB stars (Fishlock+, 2014)
J/ApJ/801/69 : Iron EWs for 21 giant stars of NGC3201 (Mucciarelli+, 2015)
J/MNRAS/450/815 : Red giants in NGC 5286 (Marino+, 2015)
J/A+A/581/A72 : ubvy photometry of NGC2419 (Frank+, 2015)
J/MNRAS/463/696 : M67 solar twins chemical compositions (Liu+, 2016)
J/MNRAS/471/1446 : Ground-based proper motion of 12 nearby GC (Narloch+, 2017)
J/ApJ/864/57 : Abundances of field & GC RR Lyrae I. NGC3201 (Magurno+, 2018)
J/A+A/614/A146 : Stellar parameters of NGC3201 RGB stars (Dias+, 2018)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/A+A/628/A54 : Fe, Mg, Ti in Galactic clusters (Kovalev+, 2019)
J/A+A/632/A3 : MUSE binaries in NGC 3201 (Giesers+, 2019)
J/MNRAS/485/3042 : UBVRI photometry in 48 globular clusters (Stetson+, 2019)
J/MNRAS/488/3024 : GC members with Gaia DR2 (Bustos Fierro+, 2019)
J/A+A/635/A114 : EW & [Fe/H] for 30000 GC RGB stars (Husser+ 2020)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [14/160] Identifier
5- 6 I2 h RAh Hour of right ascension (J2000)
8- 9 I2 min RAm Minute of right ascension (J2000)
11- 16 F6.3 s RAs Second of right ascension (J2000)
18 A1 --- DE- Sign of declination (J2000)
19- 20 I2 deg DEd Degree of declination (J2000)
22- 23 I2 arcmin DEm Arcminute of declination (J2000)
25- 29 F5.2 arcsec DEs Arcsecond of declination (J2000)
31- 36 F6.3 mag Vmag [13.64/15.42] V-band magnitude
38- 43 F6.3 mag Color1 [-0.28/0.08] ΔF275W,F814W
45- 50 F6.3 mag Color2 [-0.02/0.1] ΔF275W,F336W,F438W
52- 56 F5.1 km/s RV [490.8/506.8] Radial velocity
58- 61 F4.2 km/s e_RV [0.08/0.8] RV uncertainty
63- 64 I2 --- Nexp [5/23] Number of exposures
66- 73 A8 --- delT Time interval
(maximum time between observations)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [14/160] Star number
5- 8 I4 K Teff [4650/5000] Effective temperature
10- 13 F4.2 [cm/s2] logg [1.6/2.53] Log of surface gravity
15- 19 F5.2 [Sun] [A/H] [-1.68/-1.39] Abundance of [A/H]
21- 24 F4.2 km/s Vt [1.36/1.64] Microturbulent velocity
26- 29 F4.2 [-] logFeI [5.82/6.11] log of FeI abundance
31- 34 F4.2 [-] e_logFeI [0.08/0.11] LogFeI uncertainty
36- 38 I3 --- o_logFeI [110/133] Number of observations for logFeI
40- 43 F4.2 [-] logFeII [5.88/6.18] log of FeII abundance
45- 48 F4.2 [-] e_logFeII [0.04/0.09] LogFeII uncertainty
50- 51 I2 --- o_logFeII [12/13] Number of observations for logFeII
53- 56 I4 K Teffp [4507/4940] Photometric effective temperature
58- 61 F4.2 [cm/s2] loggp [1.54/2.48] Photometric logg
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [14/160] Star number
5- 12 F8.3 0.1nm lambda [4788.7/6806.9] Wavelength in Angstrom units
14- 17 F4.1 --- Ion [11/60.1] Chemical species
19- 23 F5.3 eV EP [0/5.62] Excitation potential
25- 30 F6.3 [-] loggf [-6/0.63] Total oscillator strength
32- 36 F5.1 0.1pm EW [2/175.3] Equivalent width
in milli-Angstrom units
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-May-2021