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J/ApJ/712/L21     Calcium abundances in 17 globular clusters   (Carretta+, 2010)
Calcium and light-elements abundance variations from high-resolution
spectroscopy in globular clusters.
    Carretta E., Bragaglia A., Gratton R., Lucatello S., Bellazzini M.,
    D'Orazi V.
   <Astrophys. J., 712, L21-L25 (2010)>
   =2010ApJ...712L..21C
ADC_Keywords: Abundances ; Clusters, globular ; Stars, giant

Keywords: globular clusters: general - stars: abundances - stars: evolution


Abstract:
    We use abundances of Ca, O, Na, and Al from high-resolution UVES
    spectra of 200 red giants in 17 globular clusters (GCs) to investigate
    the correlation found by Lee et al. (2009Icar..199..413C) between
    chemical enrichment from SNII and star-to-star variations in light
    elements in GC stars. We find that (1) the [Ca/H] variations between
    first and second generation stars are tiny in most GCs (∼0.02-0.03dex,
    comparable with typical observational errors). In addition, (2) using
    a large sample of red giants in M4 (NGC 6121) with abundances from
    UVES spectra from Marino et al. (2008, Cat. J/A+A/490/625), we find
    that Ca and Fe abundances in the two populations of Na-poor and
    Na-rich stars are identical.

Description:
    The full description of the analysis is given in Carretta et al.
    (2009, Cat. J/A+A/505/139); here we present only the abundances of Ca,
    which are based on a large number of lines (typically 10-12 in the
    most metal-poor clusters like M15 (NGC 7078) and almost 20 in
    metal-rich GCs like 47 Tuc (NGC 104)).

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        40      202   The [Ca/Fe] and [Ca/H] ratios for individual stars
table2.dat        43       17   Mean [Ca/Fe], [Ca/H] ratios and internal errors
                            for the 17 globular clusters


See also:
   J/A+A/505/139 : Abundances of red giants in 17 globular clusters (Carretta+,
                   2009)
   J/A+A/503/545 : Equivalent widths of Li, Na, Fe, Ca in NGC 6397 (Lind+, 2009)
   J/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008)
   J/A+A/490/777 : Abundances of Population II stars in NGC 6397 (Lind+, 2008)
   J/A+A/486/941 : Abundances in M71 (NGC 6838) (Alves-Brito+, 2008)
   J/A+A/464/939 : Abundances of red giants in NGC 6218 (Carretta+, 2007)
   J/A+A/464/927 : Abundances of red giants in NGC 6752 (Carretta+, 2007)
   J/AJ/131/1766 : Abundances and equivalent widths in NGC 2808 (Carretta, 2006)
   J/A+A/434/235 : Abundances of BHB stars in NGC 1904 (Fabbian+, 2005)
   J/A+A/440/901 : Reddening and metallicity of NGC 6752 (Gratton, 2005)


Byte-by-byte Description of file: table1.dat

   Bytes Format Units   Label     Explanations

   1-  3  A3    ---     ---       [NGC]
   4-  7  I4    ---     NGC       NGC number of the globular cluster
   9- 15  I7    ---     ID        Star identification (1)
  17- 18  I2    ---     NCa       Number of Ca lines
  20- 25  F6.3  [Sun]   [Ca/Fe]   The [Ca/Fe] abundance ratio
  27- 31  F5.3  [Sun]  e_[Ca/Fe]  The rms error in Ca/Fe
  33- 38  F6.3  [Sun]   [Ca/H]    The [Ca/H] abundance ratio
      40  I1    ---     PIE       [0,3] PIE flag (2)

Note (1): Stars are <[CBG2009] NGC NNNN NNNNNNN> in Simbad.

Note (2): 1, 2, and 3 for the primordial P, intermediate I and extreme E
          component, respectively; 0 means that either Na or O was missing and
          the star could be not assigned to a component.


Byte-by-byte Description of file: table2.dat

   Bytes Format Units   Label     Explanations

   1-  3  A3    ---     ---       [NGC]
   5-  8  I4    ---     NGC       NGC number of the globular cluster
  10- 11  I2    ---     N         Number of stars studied in the cluster
  13- 17  F5.2  [Sun]   [Ca/Fe]   The [Ca/Fe] abundance ratio
  19- 22  F4.2  [Sun]  e_[Ca/Fe]  The rms error in [Ca/Fe]
  24- 27  F4.2  [Sun]   err1      Error 1 (1)
  29- 32  F4.2  [Sun]   err2      Error 2 (1)
  34- 38  F5.2  [Sun]   [Ca/H]    The [Ca/H] abundance ratio
  40- 43  F4.2  [Sun]   e_[Ca/H]  The rms error in [Ca/H]

Note (1): err1 for [Ca/Fe] accounts for internal errors in Teff, vt,
     and EW, whereas err2 includes all sources of uncertainties (see
     Carretta et al. 2009, Cat. J/A+A/505/139).


History:
    From electronic version of the journal
(End)                 Greg Schwarz [AAS], Emmanuelle Perret [CDS]    11-Apr-2012