J/ApJ/689/1031 Heavy element abundances in giant stars (Yong+, 2008)
Heavy element abundances in giant stars of the globular clusters M4 and M5. Yong D., Karakas A.I., Lambert D.L., Chieffi A., Limongi M. <Astrophys. J., 689, 1031-1043 (2008)> =2008ApJ...689.1031Y
ADC_Keywords: Equivalent widths ; Abundances ; Stars, giant ; Clusters, globular Keywords: Galaxy: abundances - globular clusters: individual (M4, M5) - stars: abundances Abstract: We present a comprehensive abundance analysis of 27 heavy elements in bright giant stars of the globular clusters M4 and M5 based on high-resolution, high signal-to-noise ratio spectra obtained with the Magellan Clay Telescope. We confirm and expand on previous results for these clusters by showing that (1) all elements heavier than, and including, Si have constant abundances within each cluster, (2) the elements from Ca to Ni have indistinguishable compositions in M4 and M5, (3) Si, Cu, Zn, and all s-process elements are approximately 0.3dex overabundant in M4 relative to M5, and (4) the r-process elements Sm, Eu, Gd, and Th are slightly overabundant in M5 relative to M4. The cluster-to-cluster abundance differences for Cu and Zn are intriguing, especially in light of their uncertain nucleosynthetic origins. We confirm that stars other than Type Ia supernovae must produce significant amounts of Cu and Zn at or below the clusters' metallicities. If intermediate-mass AGB stars or massive stars are responsible for the Cu and Zn enhancements in M4, the similar [Rb/Zr] ratios and (preliminary) Mg isotope ratios in both clusters may be problematic for either scenario. For the elements from Ba to Hf, we assume that the s- and r-process contributions are scaled versions of the solar s- and r-process abundances. We quantify the relative fractions of s- and r-process material for each cluster and show that they provide an excellent fit to the observed abundances. Description: The sample consists of 12 bright giants in M4 and 2 bright giants in M5 observed with the high-resolution spectrograph MIKE on the Magellan Clay Telescope on 2004 June 12-13, July 16, and July 18. These are the same high-quality spectra analyzed by Yong et al. (2008ApJ...673..854Y; R=55000, wavelength coverage from 3800 to 8500Å, and S/N=140 per resolution element at 4000Å and S/N=800 per resolution element at 7800Å). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 29 14 Stellar parameters from Yong et al. (2008ApJ...673..854Y) table2.dat 46 1162 Equivalent widths
See also: J/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008) J/ApJS/169/120 : Transition probabilities for HfII and Hf (Lawler+, 2007) J/ApJS/162/227 : Transition probabilities for SmII (Lawler+, 2006) J/ApJS/167/292 : Laboratory transition probabilities for Gd II (Den Hartog+, 2006) J/AJ/129/303 : Abundances of stars in M3 and M13 (Cohen+, 2005) J/MNRAS/340/304 : [X/Fe] of Galactic disc F and G dwarfs (Reddy+, 2003) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name Star designation 10- 13 I4 K Teff Effective temperature (1) 15- 18 F4.2 [cm/s2] logg Surface gravity (1) 20- 23 F4.2 km/s xi Microturbulent velocity (ξ_t_) (1) 25- 29 F5.2 [-] [Fe/H] Fe/H abundance
Note (1): We estimate that the internal errors are Teff±50K, logg±0.2dex, and ξt±0.2km/s. For further details regarding the observations, data reduction, and derivation of stellar parameters, see Yong et al. (2008ApJ...673..854Y).
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name Star designation 10- 17 F8.3 0.1nm lambda Wavelength in Angstroms (Å) 19- 22 F4.1 --- Sp Species identification (1) 24- 27 F4.2 eV ExPot Excitation potential 29- 33 F5.2 [-] log(gf) Log of the oscillator strength 35- 38 A4 --- r_log(gf) Reference for log(gf) (2) 40- 44 F5.1 0.1pm EW ? Equivalent width in milli-Angstrom (mÅ) 46 A1 --- f_EW [s] synthetic EW (3)
Note (1): In the format XX.YY where XX is the atomic number and YY is the ionization level, e.g. 14.00=SiI. Note (2): References as follows: M05 = Cohen & Melendez (2005; Cat. J/AJ/129/303); CS02 = Cunha et al. (2002AJ....124..379C); DL03 = Den Hartog et al. (2003ApJS..148..543D); DL06 = Den Hartog et al. (2006; Cat. J/ApJS/167/292); IK01 = Ivans et al. (1999AJ....118.1273I); KB95 = Kurucz & Bell (1995all..book.....K); LD06 = Lawler et al. (2006; Cat. J/ApJS/162/227); LH07 = Lawler et al. (2007; Cat. J/ApJS/169/120); LUCK = R. E. Luck (priv. comm.); ND95 = Norris et al. (1995ApJ...447..680N); NZ02 = Nilsson et al. (2002A&A...382..368N); PN00 = Prochaska et al. (2000AJ....120.2513P); RC02 = Ramirez & Cohen (2002AJ....123.3277R); RT03 = Reddy et al. (2003; Cat. J/MNRAS/340/304); SS00 = Smith et al. (2000AJ....119.1239S). Note (3): s = abundance determined by generating synthetic spectrum using MOOG and adjusting the abundance to match the observed spectrum.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 24-Jan-2011
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