J/ApJ/864/57 Abundances of field & GC RR Lyrae. I. NGC3201 (Magurno+, 2018)
Chemical compositions of field and globular cluster RR Lyrae stars.
I. NGC 3201.
Magurno D., Sneden C., Braga V.F., Bono G., Mateo M., Persson S.E.,
Dall'Ora M., Marengo M., Monelli M., Neeley J.R.
<Astrophys. J., 864, 57 (2018)>
=2018ApJ...864...57M 2018ApJ...864...57M
ADC_Keywords: Abundances; Stars, variable; Clusters, globular;
Radial velocities
Keywords: globular clusters: individual (NGC 3201) ; stars: abundances ;
stars: variables: RR Lyrae ; techniques: spectroscopic
Abstract:
We present a detailed spectroscopic analysis of horizontal branch
stars in the globular cluster NGC 3201. We collected optical
(4580-5330Å), high-resolution (∼34000), high signal-to-noise ratio
(∼200) spectra for 11 RR Lyrae stars and one red horizontal branch
star with the multifiber spectrograph M2FS with the 6.5m Magellan
telescope at the Las Campanas Observatory. From measured equivalent
widths, we derived atmospheric parameters and abundance ratios for
α (Mg, Ca and Ti), iron-peak (Sc, Cr, Ni and Zn), and s-process
(Y) elements. We found that NGC 3201 is a homogeneous, monometallic
([Fe/H]=-1.47±0.04), α-enhanced ([α/Fe]=0.37±0.04)
cluster. The relative abundances of the iron-peak and s-process
elements were found to be consistent with solar values. In comparison
with other large stellar samples, NGC 3201 RR Lyraes have similar
chemical enrichment histories as do those of other old (t≥10Gyr) Halo
components (globular clusters; red giants; blue and red horizontal
branch stars; and RR Lyraes). We also provided a new average radial
velocity estimate for NGC 3201 by using a template velocity curve to
overcome the limit of single-epoch measurements of variable stars:
Vrad=494±2km/s (σ=8km/s).
Description:
In 2015 February, we collected spectra for 11 RR Lyrae stars (RRLs)
and one red horizontal branch (RHB) star in the globular cluster
NGC3201 (Figure 1) using the Michigan/Magellan Fiber System (M2FS)
installed at the Magellan/Clay 6.5m telescope at the Las Campanas
Observatory in Chile. All the observed variables are RRab. We derived
velocities and, from measured equivalent widths, atmospheric
parameters and abundance ratios.
We compare our results with estimated abundances for RR Lyrae stars
using high-resolution (R>20000) spectroscopy, estimated by 10
different authors in the period from 1995 to 2017. We collected here
the abundances of Fe, Mg, Ca, and Ti (Table 10), and Sc, Cr, Ni, Zn,
and Y (Table 11) for 147 field RRLs (96 objects). They are all scaled
to the solar reference by Asplund+ (2009ARA&A..47..481A 2009ARA&A..47..481A).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 93 12 Photometric parameters for the sample stars
in NGC 3201
table2.dat 55 12 Instantaneous radial velocity, systemic velocity
from template, and estimated stellar parameters
table10.dat 47 220 Iron and alpha-elements abundances of
high-resolution field RRLs (138 stars)
table11.dat 53 120 Iron peak and s-process elements abundances of
high-resolution field RRLs (88 stars)
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See also:
J/AJ/108/1016 : Kinematics of local RR lyrae stars. I. (Layden, 1994)
J/AJ/110/2319 : Abundances in RR Lyr variables (Clementini+ 1995)
J/A+AS/121/95 : Giant stars abundances in 24 clusters (Carretta+ 1997)
J/AJ/124/1464 : Variable stars in Andromeda VI (Pritzl+, 2002)
J/ApJ/617/1091 : La and Eu abundances in 85 stars (Simmerer+, 2004)
J/AJ/130/2140 : Abundances & velocities in globular clusters (Pritzl+, 2005)
J/MNRAS/367/1329 : Elemental abundances for 176 stars (Reddy+, 2006)
J/ApJ/667/1267 : CrI transition probabilities (Sobeck+, 2007)
J/A+A/505/139 : Abundances of red giants in 17 GCs (Carretta+, 2009)
J/AcA/59/1 : VI light curves of LMC RR Lyrae stars (Soszynski+, 2009)
J/ApJ/712/L21 : Calcium abundances in 17 globular clusters (Carretta+, 2010)
J/AJ/140/1694 : Abundances of non-variable red & blue HB stars (For+, 2010)
J/AN/331/474 : Abundances of metal-poor stars (Frebel, 2010)
J/ApJS/197/29 : Chemical compositions of 11 RR Lyrae (For+, 2011)
J/AJ/141/90 : SEGUE stellar parameter pipeline. V. (Lee+, 2011)
J/MNRAS/427/3374 : QUEST RR Lyrae Survey III. Low Gal. latitude (Mateu+, 2012)
J/MNRAS/422/89 : Cetus dSph RR Lyrae (Monelli+, 2012)
J/AJ/144/114 : Radial velocities of 6 field RR Lyrae (Sesar+, 2012)
J/ApJ/763/32 : Galactic halo RRab stars from CSS (Drake+, 2013)
J/ApJS/208/27 : Sun and HD 84937 TiII log(gf) and abundances (Wood+, 2013)
J/ApJS/213/31 : Blazhko effect from 4yr of Kepler data (Benko+, 2014)
J/ApJS/215/23 : FeI branching fractions (Den Hartog+, 2014)
J/ApJ/782/59 : Abundances of 8 RR Lyrae subclass C var. stars (Govea+, 2014)
J/MNRAS/441/3127 : FeI oscillator strengths for Gaia-ESO (Ruffoni+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/PASP/126/521 : UBVRIJHK photometry of RR Lyrae in M4 (Stetson+, 2014)
J/ApJS/211/20 : NiI transition probability measurements (Wood+, 2014)
J/ApJ/801/69 : Iron EWs for NGC3201 giant star members (Mucciarelli+, 2015)
J/MNRAS/447/2404 : Equivalent width of 21 RR Lyrae stars (Pancino+, 2015)
J/MNRAS/446/2251 : Southern Catalina Survey type-ab RR Lyrae (Torrealba+, 2015)
J/MNRAS/462/4349 : Variable stars in Sculptor dSph (Martinez-Vazquez+, 2016)
J/ApJS/228/10 : Transition probabilities for Cr II lines (Lawler+, 2017)
J/ApJ/842/60 : Var. stars in Logal Group galaxies. III. (Monelli+, 2017)
J/ApJ/841/84 : Theoretical framework for RR Lyrae. II. MIR (Neeley+, 2017)
J/ApJ/848/68 : Abundances & RVs of stable & Blazhko RRc stars (Sneden+, 2017)
J/AJ/155/137 : RRLs in GCs. V.ω Centauri NIR photom. (Braga+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- ID RRab star identifier
7- 8 I2 h RAh Hour of right ascension (J2000)
10- 11 I2 min RAm Minute of right ascension (J2000)
13- 17 F5.2 s RAs Second of right ascension (J2000)
19 A1 --- DE- Sign of declination (J2000)
20- 21 I2 deg DEd Degree of declination (J2000)
23- 24 I2 arcmin DEm Arcminute of declination (J2000)
26- 29 F4.1 arcsec DEs Arcsecond of declination (J2000)
31- 40 F10.8 d Per [0.5/0.7]? Period
42- 51 F10.5 d HJD [7079.7/7079.8] Heliocentric Julian Date;
HJD-2450000
53- 62 F10.5 d HJD0 [4123/7961.2]? Heliocentric Julian
Date; JD-2450000
64- 67 F4.2 --- Phase [0.09/0.9]? Phase
69- 72 A4 --- Type RR Lyrae type (always "RRab")
74 A1 --- f_Type b = Blazhko
76- 80 F5.2 mag Vmag [13.8/15] Mean V-band magnitude
82- 85 F4.2 mag Vamp [0.4/1.3]? V-band amplitude
87- 93 A7 --- Ref Reference(s) (1)
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Note (1): References as follows:
N = J. R. Neeley et al. (2018, in preparation),
L03 = Layden & Sarajedini (2003AJ....125..208L 2003AJ....125..208L),
ASN = ASAS-SN (Shappee+ 2014, J/ApJ/788/48 & Jayasinghe+ 2018MNRAS.477.3145J 2018MNRAS.477.3145J).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- ID RRab star identifier
7- 11 F5.1 km/s RV [463.5/520.5] Radial velocity
13- 15 F3.1 km/s e_RV [0.3/1.2] RV uncertainty
17- 19 I3 km/s Vgamma [477/505] Integral average velocity
along the pulsation cycle
21 I1 km/s e_Vgamma [8/8] Vγ uncertainty
23- 26 I4 K Teff [5600/7500] Effective temperature
28- 30 I3 K e_Teff [100/300] Teff uncertainty
32- 34 F3.1 [cm/s2] logg [2.1/3.3] Log of surface gravity
36- 38 F3.1 [cm/s2] e_logg [0.1/0.4] logg uncertainty
40- 42 F3.1 km/s Vt [2.2/3.6] Microturbulence
44- 46 F3.1 km/s e_Vt [0.1/0.4] Vt uncertainty
48- 51 F4.1 [Sun] [M/H] [-1.8/-1.2] Metallicity
53- 55 F3.1 [Sun] e_[M/H] [0.1/0.1] [M/H] uncertainty
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Name Star name
21- 25 F5.2 [Sun] [Fe/H] [-2.9/0.2] Iron abundance
27- 31 F5.2 [Sun] [Mg/Fe] [-0.05/0.9]? Magnesium over iron abundance
33- 37 F5.2 [Sun] [Ca/Fe] [-0.2/0.6]? Calcium over iron abundance
39- 43 F5.2 [Sun] [Ti/Fe] [-0.5/0.8]? Titanium over iron abundance
45- 47 A3 --- Ref Reference paper (G1)
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Byte-by-byte Description of file: table11.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Name Star name
21- 25 F5.2 [Sun] [Sc/Fe] [-0.8/0.5]? Scandium over iron abundance
27- 31 F5.2 [Sun] [Cr/Fe] [-0.3/0.4]? Chromium over iron abundance
33- 37 F5.2 [Sun] [Ni/Fe] [-0.2/0.9]? Nickel over iron abundance
39- 43 F5.2 [Sun] [Zn/Fe] [-0.2/0.6]? Zinc over iron abundance
45- 49 F5.2 [Sun] [Y/Fe] [-0.8/0.5]? Yttrium over iron abundance
51- 53 A3 --- Ref Reference paper (G1)
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Global notes:
Note (G1): Reference as follows:
C95 = Clementini+ 1995, J/AJ/110/2319
L96 = Lambert+ 1996ApJS..103..183L 1996ApJS..103..183L
K10 = Kolenberg+ 2010A&A...519A..64K 2010A&A...519A..64K
F11 = For+ J/ApJS/197/29
H11 = Hansen+ 2011A&A...527A..65H 2011A&A...527A..65H
L13 = Liu+ 2013RAA....13.1307L 2013RAA....13.1307L
G14 = Govea+ J/ApJ/782/59
P15 = Pancino+ J/MNRAS/447/2404
C17 = Chadid+ 2017ApJ...835..187C 2017ApJ...835..187C
S17 = Sneden+ 2017, J/ApJ/848/68
All scaled to Solar abundances by Asplund+ 2009ARA&A..47..481A 2009ARA&A..47..481A
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 14-Aug-2019