J/ApJ/740/60 Equivalent widths for NGC2419 and NGC7099 RGB stars (Cohen+, 2011)
The peculiar chemical inventory of NGC 2419: an extreme outer halo
"Globular cluster".
Cohen J.G., Huang W., Kirby E.N.
<Astrophys. J., 740, 60 (2011)>
=2011ApJ...740...60C 2011ApJ...740...60C
ADC_Keywords: Clusters, globular ; Equivalent widths ; Abundances, [Fe/H] ;
Radial velocities
Keywords: Galaxy: formation - Galaxy: halo -
globular clusters: individual (NGC 2419)
Abstract:
NGC 2419 is a massive outer halo Galactic globular cluster (GC) whose
stars have previously been shown to have somewhat peculiar abundance
patterns. We have observed seven luminous giants that are members of
NGC 2419 with Keck/HIRES at reasonable signal-to-noise ratio. One of
these giants is very peculiar, with an extremely low [Mg/Fe] and high
[K/Fe] but normal abundances of most other elements. The abundance
pattern does not match the nucleosynthetic yields of any supernova
model. The other six stars show abundance ratios typical of inner halo
Galactic GCs, represented here by a sample of giants in the nearby GC
M30. Although our measurements show that NGC 2419 is unusual in some
respects, its bulk properties do not provide compelling evidence for a
difference between inner and outer halo GCs.
Description:
We obtained high-spectral-resolution and reasonably high
signal-to-noise ratio (S/N) spectra of seven luminous giants in NGC 2419
using HIRESr on the Keck I 10m Telescope in 2010, 2008 or 2006. The
stars were selected from both the early spectroscopic study of
Suntzeff et al. (1988AJ.....95...91S 1988AJ.....95...91S) and the current version of the
online photometric database described by Stetson
(2005PASP..117..563S 2005PASP..117..563S). Cohen et al. (2010, Cat. J/ApJ/719/931)
discussed membership issues for NGC 2419 in detail.
Our sample of five RGB members in the sparse nearby GC M30 (NGC 7099)
were observed with the same HIRES configuration in September 2006; all
the resulting spectra are of high S/N.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 70 12 Data for red giant members of NGC 2419 and of
NGC 7099 with HIRES/Keck spectra
ew2419.dat 50 2310 Equivalent widths for NGC 2419 RGB stars (table 3)
ew7099.dat 50 1890 Equivalent widths for NGC 7099 RGB stars (table 4)
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See also:
J/ApJ/738/186 : HST and DEIMOS measurements of NGC 2419 stars (Ibata+, 2011)
J/AJ/141/81 : NGC 2419 variable star population (Di Criscienzo+, 2011)
J/ApJ/719/931 : Chemical evolution of the UMi dSph (Cohen+, 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/AJ/136/2259 : HST photometry of stars in NGC 2419 (Sandquist+, 2008)
J/ApJ/682/1217 : Abundances in red giants in 7 globular clusters (Kirby+, 2008)
J/A+A/462/L9 : Radial velocities in NGC 7099 (Scarpa+, 2007)
J/PASP/117/37 : BVRI photometry in NGC 2419, Pal 4, and Pal 14 (Saha+, 2005)
J/ApJ/518/262 : CCD VIc Photometry of M30 Stars (Sandquist+, 1999)
J/AJ/112/1061 : BV photometry of NGC 7099 (Bergbusch 1996)
http://www2.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/community/STETSON
/standards/NGC2419.pho : Online photometry of NGC2419 from P. Stetson
http://www2.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/community/STETSON
/standards/NGC7099.pho : Online photometry of NGC7099 from P. Stetson
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [NGC]
5- 8 I4 --- NGC Number of the globular cluster (2419 or 7099)
11- 15 A5 --- ID Identification of star in cluster (G1)
17 A1 --- n_ID [e-l] Individual notes on star (1)
19- 23 F5.2 mag Vmag V-band magnitude from the online version of
the database of Stetson (2005PASP..117..563S 2005PASP..117..563S)
25 A1 --- r_Vmag [k] k = Vmag from Bolte (1987ApJ...319..760B 1987ApJ...319..760B)
27- 30 I4 K Teff Effective temperature
32- 35 F4.2 [cm/s2] logg Surface gravity
37- 39 F3.1 km/s Vt [1.8/2.4] Microturbulent velocity
41- 45 F5.2 [Sun] [Fe/H] Metallicity
47- 53 A7 "MM/YYYY" Date Date of the best spectrum (2)
55- 58 I4 s Exp Exposure time
60 A1 --- l_S/N Limit flag on S/N
61- 63 I3 --- S/N Signal to noise ratio per spectral resolution
element in the continuum at 5500Å
65- 70 F6.1 km/s HRV Heliocentric radial velocity
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Note (1): Flag as follows:
e = Stetson 223 = Suntzeff 1 (Suntzeff et al. 1988AJ.....95...91S 1988AJ.....95...91S;
<Cl* NGC 2419 SKK NN> in Simbad).
f = Stetson 973 = Suntzeff 15
g = Stetson 1209 = Suntzeff 16
h = Stetson 1305 = Cl* NGC 2419 RH 10 (M. Shetrone 2009, private
communication), previously observed by Shetrone et al.
(2001ApJ...548..592S 2001ApJ...548..592S).
i = Stetson 1814 = Suntzeff 14
j = ID from Alcaino & Liller (1980AJ.....85.1330A 1980AJ.....85.1330A).
l = S81 lies slightly bluer in B-V than the mean RGB locus.
Note (2): Earlier low S/N spectra were taken for several of the NGC 2419 stars.
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Byte-by-byte Description of file: ew2419.dat ew7099.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [NGC]
5- 8 I4 --- NGC NGC number (2419 or 7099)
10- 14 A5 --- ID RGB star identification (G1)
16- 22 F7.2 0.1nm lambda Wavelength λ (Å)
24- 28 A5 --- Ion Ion identification
30- 33 A4 eV ExPot Excitation potential
35- 41 F7.3 [-] log(gf) Log of the oscillator strength
43- 44 A2 --- l_EW [≤] Limit flag on EW
46- 50 F5.1 10-13m EW ? Equivalent width (mÅ)
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Global Notes:
Note (G1): The identification is from online data of P. Stetson
(2005PASP..117..563S 2005PASP..117..563S) if starts by "S", or from Alcaino and Liller
(1980AJ.....85.1330A 1980AJ.....85.1330A) if starts by "A".
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 04-Feb-2013