J/ApJ/836/168 Abundances & RVs for stars near (or in) NGC6273 (Johnson+, 2017)
A chemical composition survey of the iron-complex globular cluster NGC 6273
(M19).
Johnson C.I., Caldwell N., Rich R.M., Mateo M., Bailey III J.I.,
Clarkson W.I., Olszewski E.W., Walker M.G.
<Astrophys. J., 836, 168-168 (2017)>
=2017ApJ...836..168J 2017ApJ...836..168J (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Abundances ; Stars, giant ;
Radial velocities ; Equivalent widths ; Photometry, infrared
Keywords: globular clusters: general;
globular clusters: individual: (NGC 6273, M19); stars: abundances
Abstract:
Recent observations have shown that a growing number of the most
massive Galactic globular clusters contain multiple populations of
stars with different [Fe/H] and neutron-capture element abundances.
NGC 6273 has only recently been recognized as a member of this
"iron-complex" cluster class, and we provide here a chemical and
kinematic analysis of >300 red giant branch and asymptotic giant
branch member stars using high-resolution spectra obtained with the
Magellan-M2FS and VLT-FLAMES instruments. Multiple lines of evidence
indicate that NGC 6273 possesses an intrinsic metallicity spread that
ranges from about [Fe/H]=-2 to -1 dex, and may include at least three
populations with different [Fe/H] values. The three populations
identified here contain separate first (Na/Al-poor) and second
(Na/Al-rich) generation stars, but a Mg-Al anti-correlation may only
be present in stars with [Fe/H]≳-1.65. The strong correlation between
[La/Eu] and [Fe/H] suggests that the s-process must have dominated the
heavy element enrichment at higher metallicities. A small group of
stars with low [α/Fe] is identified and may have been accreted
from a former surrounding field star population. The cluster's large
abundance variations are coupled with a complex, extended, and
multimodal blue horizontal branch (HB). The HB morphology and chemical
abundances suggest that NGC 6273 may have an origin that is similar to
ω Cen and M54.
Description:
In order to efficiently obtain a large number of high-resolution
spectra, we employed the Michigan/Magellan Fiber System (M2FS) and
MSpec multi-object spectrograph mounted on the Magellan-Clay 6.5m
telescope (R∼27000).
We supplemented the M2FS CaT data set with additional observations of
300 RGB stars taken with the VLT FLAMES-GIRAFFE instrument. The data
were downloaded from the European Southern Observatory (ESO) Science
Archive Facility (R∼18000 from 8482 to 9000Å).
In support of our spectroscopic observations, we have obtained new HST
Wide Field Camera 3 UVIS channel (WFC3/UVIS) data centered on NGC 6273
that includes the F336W, F438W, F555W, and F814W filters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 66 18 Observing log
table2.dat 69 333 Star identifiers, coordinates, photometry, and
radial velocities for NGC 6273 members
table3.dat 69 515 Star identifiers, coordinates, photometry, and
radial velocities for non-members
table4.dat 39 59 Model atmosphere parameters for NGC 6273 members
table5.dat 82 59 Chemical abundances for NGC 6273 members: Na-Cr
table6.dat 73 59 Chemical abundances for NGC 6273 members: Fe-Eu
table7.dat 51 274 Calcium triplet metallicity data
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See also:
B/eso : ESO Science Archive Catalog (ESO, 1991-2016)
VII/195 : Globular Clusters in the Milky Way (Harris, 1996)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
V/150 : Updated catalog of variable stars in GCs (Clement+ 2017)
J/AJ/112/545 : Proton capture chains in GCs. I. (Pilachowski+ 1996)
J/PASP/109/883 : Globular metallicity scale. I. (Rutledge+ 1997)
J/A+A/391/945 : HST photometry of 74 galactic GCs (Piotto+, 2002)
J/AJ/130/2140 : Abundances & velocities in globular clusters (Pritzl+, 2005)
J/AJ/134/1298 : CaII equivalent widths in 29 GCs (Carrera+, 2007)
J/AJ/133/1287 : JHK photom. of 24 Galactic globular clusters (Valenti+, 2007)
J/MNRAS/383/183 : CaII triplet of RGB from VLT/FLAMES obs. (Battaglia+, 2008)
J/A+A/486/177 : Bulge field stars from FLAMES-GIRAFFE sp. (Zoccali+, 2008)
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/705/1481 : Spectrosc. of stars in 6 globular clusters (Da Costa+, 2009)
J/MNRAS/404/1529 : s-process in low-metallicity stars (Bisterzo+, 2010)
J/AJ/143/70 : Differential reddening in MW globulars (Alonso-Garcia+, 2012)
J/A+A/540/A27 : Spectroscopy in Galactic globular clusters (Saviane+, 2012)
J/A+A/549/A147 : Microlensed bulge dwarf star abundances. V. (Bensby+, 2013)
J/other/Nat/498.198 : Na abundances in NGC6752 (Campbell+, 2013)
J/MNRAS/434/1681 : Extremely metal-poor stars CaII triplet (Carrera+, 2013)
J/ApJ/769/40 : Potassium abundance in red giants of GCs (Carretta+, 2013)
J/ApJ/765/157 : Red giant abundances in the Galactic bulge (Johnson+, 2013)
J/A+A/563/A76 : CaII triplet equivalent widths in 30 globulars (Mauro+, 2014)
J/A+A/562/A66 : GIRAFFE Inner Bulge Survey (GIBS). I. (Zoccali+, 2014)
J/AJ/149/53 : RVs of 12 Milky Way globular clusters (Kimmig+, 2015)
J/A+A/573/A115 : Radial velocities in seven globular clusters (Lardo+, 2015)
J/ApJS/219/7 : Ca,by photometry in globular clusters. I. M22 (Lee, 2015)
J/ApJS/216/19 : Spectroscopic HK' index for 3 globular clusters (Lim+, 2015)
J/AJ/149/153 : Abundances of red giants in 10 GCs (Meszaros+, 2015)
J/A+A/580/A121 : CaT/[Fe/H] for Galactic bulge stars (Vasquez+, 2015)
J/MNRAS/455/199 : CaII triplet in red giant spectra (Da Costa, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Obs Observation (P=Photometry; S=Spectroscopy)
3- 4 A2 --- Field Field (1)
6- 18 A13 --- Tel Telescope/Instrument
20- 28 A9 --- Setup Instrument setup
30- 43 A14 "Y/M/D" Date UT Date of Observation
45- 66 A22 s Exp Exposure sequence(s)
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Note (1): Fields with different designations indicate different telescope
pointings. The "a" and "b" designations for the VLT--FLAMES setups
correspond to the "HIERARCH ESO OBS NAME" keyword in the original image
headers. The "a" and "b" fields with the same numbers typically
observed the same stars, but sometimes with different fibers.
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Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1 I1 --- Set Sample (G1)
3- 18 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs; J2000)
20 A1 --- f_2MASS Observation notes (G2)
22- 31 F10.6 deg RAdeg Right Ascension, decimal degrees (J2000) (1)
33- 42 F10.6 deg DEdeg Declination, decimal degrees (J2000) (1)
44- 49 F6.3 mag Jmag [10.3/16.2] 2MASS J magnitude (1)
51- 56 F6.3 mag Ksmag [9.3/16.5] 2MASS Ks magnitude (1)
58- 64 F7.2 km/s HRV [-351/347] Heliocentric radial velocity
(range between ∼120-165km/s for the members)
66- 69 F4.2 km/s e_HRV [0.1/6] Uncertainty in HRV
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Note (1): Source positions and J, Ks magnitudes taken from 2MASS.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs; J2000)
18 A1 --- n_2MASS [abd] Observation notes (G2)
20- 23 I4 K Teff [4200/4900]? Effective temperature
25- 28 F4.2 cm/s2 log(g) [0.2/2.4]? Surface gravity
30- 34 F5.2 [Sun] [Fe/H] [-2/-1]? Metallicity
36- 39 F4.2 km/s xi [1.3/2.3]? Microturbulent velocity
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs; J2000)
18 A1 --- f_2MASS [a-c] Observation notes (G2)
20- 24 F5.2 [-] [NaI/Fe] [-0.2/0.7]? [NaI/Fe] abundance
26- 29 F4.2 [-] e_[NaI/Fe] ? Uncertainty for [NaI/Fe]
31- 34 F4.2 [-] [MgI/Fe] [0.2/0.6]? [MgI/Fe] abundance
36- 39 F4.2 [-] e_[MgI/Fe] ? Uncertainty for [MgI/Fe]
41- 44 F4.2 [-] [AlI/Fe] [0.1/1.3]? [AlI/Fe] abundance
46- 49 F4.2 [-] e_[AlI/Fe] ? Uncertainty for [AlI/Fe]
51- 55 F5.2 [-] [SiI/Fe] [-0.2/0.6]? [SiI/Fe] abundance
57- 60 F4.2 [-] e_[SiI/Fe] ? Uncertainty for [SiI/Fe]
62- 66 F5.2 [-] [CaI/Fe] [-0.07/0.5]? [CaI/Fe] abundance
68- 71 F4.2 [-] e_[CaI/Fe] ? Uncertainty for [CaI/Fe]
73- 77 F5.2 [-] [CrI/Fe] [-0.2/0.3]? [CrI/Fe] abundance
79- 82 F4.2 [-] e_[CrI/Fe] ? Uncertainty for [CrI/Fe]
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs; J2000)
18 A1 --- f_2MASS [a-c] Observation notes (G2)
20- 24 F5.2 [Sun] [FeI/H] [-2.1/-1]? [FeI/H] abundance
26- 29 F4.2 [Sun] e_[FeI/H] ? Uncertainty in [FeI/H]
31- 35 F5.2 [Sun] [FeII/H] [-2/-1.1]? [FeII/H] abundance
37- 40 F4.2 [Sun] e_[FeII/H] ? Uncertainty in [FeII/H]
42- 47 F6.3 [Sun] [NiI/Fe] [-0.4/0.2]? [NiI/Fe] abundance
49- 52 F4.2 [Sun] e_[NiI/Fe] ? Uncertainty in [NiI/Fe]
54- 58 F5.2 [Sun] [LaII/Fe] [-0.4/1.2]? [LaII/Fe] abundance
60- 63 F4.2 [Sun] e_[LaII/Fe] ? Uncertainty in [LaII/Fe]
65- 68 F4.2 [Sun] [EuII/Fe] [0.1/0.8]? [EuII/Fe] abundance
70- 73 F4.2 [Sun] e_[EuII/Fe] ? Uncertainty in [EuII/Fe]
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 I1 --- Set Sample (G1)
3- 18 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs; J2000)
20 A1 --- f_2MASS Observation notes (G2)
22- 25 F4.2 0.1nm W(8542) [1.5/4]? Equivalent width of CaIIλ8542
27- 30 F4.2 0.1nm W(8662) [1.2/3]? Equivalent width of CaIIλ8662
32- 35 F4.2 0.1nm sW [2.9/7]? Summed equivalent width
37- 40 F4.2 0.1nm rW [2.6/6]? Reduced equivalent width
42- 46 F5.2 [Sun] [Fe/H] [-2.3/-0.5]? Metallicity values derived
from Calcium Triplet
48- 51 F4.2 [Sun] e_[Fe/H] [0.1/0.6]? Uncertainty in [Fe/H]
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Global notes:
Note (G1): Sample as follows:
1 = Bulge_GC1 Members;
2 = M2FS Calcium Triplet Members;
3 = FLAMES Calcium Triplet Members.
Note (G2): Observation notes as follows:
a = Observed in Johnson et al. (2015AJ....150...63J 2015AJ....150...63J), the Bulge_GC1 setup,
and the M2FS Calcium Triplet setup;
b = Observed in Johnson et al. (2015AJ....150...63J 2015AJ....150...63J) and the Bulge_GC1 setup;
c = Observed in Johnson et al. (2015AJ....150...63J 2015AJ....150...63J) and the M2FS Calcium
Triplet setup;
d = Observed in the Bulge_GC1 and M2FS Calcium Triplet setups;
e = Observed in the M2FS Calcium Triplet and FLAMES Calcium Triplet setups.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 25-Sep-2017