J/MNRAS/474/4438 Stroemgren photometry of M13 (Savino+, 2018)
M13 multiple stellar populations seen with the eyes of Stromgren photometry.
Savino A., Massari D., Bragaglia A., Dalessandro E., Tolstoy E.
<Mon. Not. R. Astron. Soc., 474, 4438-4446 (2018)>
=2018MNRAS.474.4438S 2018MNRAS.474.4438S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Photometry, uvby ; Abundances
Keywords: techniques: photometric -
Hertzsprung-Russell and colour-magnitude diagrams -
stars: Population II - galaxies: star clusters: individual: NGC6205
Abstract:
We present a photometric study of M13 multiple stellar populations
over a wide field of view, covering approximately 6.5 half-light
radii, using archival Isaac Newton Telescope observations to build an
accurate multiband Stroemgren catalogue. The use of the Stroemgren
index cy permits us to separate the multiple populations of M13 on the
basis of their position on the red giant branch. The comparison with
medium and high resolution spectroscopic analysis confirms the
robustness of our selection criterion. To determine the radial
distribution of stars in M13, we complemented our data set with Hubble
Space Telescope observations of the cluster core, to compensate for
the effect of incompleteness affecting the most crowded regions. From
the analysis of the radial distributions, we do not find any
significant evidence of spatial segregation. Some residuals may be
present in the external regions where we observe only a small number
of stars. This finding is compatible with the short dynamical
time-scale of M13 and represents, to date, one of the few examples of
fully spatially mixed multiple populations in a massive globular
cluster.
Description:
The work uses Stroemgren photometry of the globular cluster NGC 6205
(M13), obtained from archival images from the Wide-Field Camera on the
Isaac Newton Telescope (INT-WFC). These come from different
observational campaigns, covering different nights from 2004, June 19
to 2013, June 14. The cross-matched spectroscopic targets (Table 2 in
the paper), come from three data sets by Sneden et al.
(2004AJ....127.2162S 2004AJ....127.2162S), Cohen & Melendez (2005, Cat. J/AJ/129/303) and
Johnson & Pilachowski (2012, Cat. J/ApJ/754/L38). Across the field of
view, 31, 22 and 106 stars, belonging respectively to these datasets
were detected.
Objects:
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RA (2000) DE Designation(s)
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16 41 41.63 +36 27 40.7 NGC 6205 = M 13
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 141 122 Spectroscopic targets
phot.dat 141 37628 Stroemgren photometry (updated file on 11/05/2020)
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See also:
J/AJ/129/303 : Abundances of stars in M3 and M13 (Cohen+, 2005)
J/A+A/505/117 : Red giants abundances in 15 globular clusters (Carretta+, 2009)
J/ApJ/754/L38 : Abundances and radial velocities of M13 giants (Johnson+, 2012)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID Internal ID from our catalogue
10- 21 F12.8 deg RAdeg Right Ascension (J2000)
27- 37 F11.8 deg DEdeg Declination (J2000)
43- 48 F6.3 mag umag Stroemgren u magnitude
53- 58 F6.3 mag vmag Stroemgren v magnitude
63- 68 F6.3 mag bmag Stroemgren b magnitude
73- 78 F6.3 mag ymag Stroemgren y magnitude
83- 88 F6.3 [-] [O/Fe]S04 ?=9.999 [O/Fe] abundance from
Sneden et al. (2004AJ....127.2162S 2004AJ....127.2162S) (1)
93- 98 F6.3 [-] [Na/Fe]S04 ?=9.999 [Na/Fe] abundance from
Sneden et al. (2004AJ....127.2162S 2004AJ....127.2162S) (1)
103-108 F6.3 [-] [O/Fe]CM05 ?=9.999 [O/Fe] abundance from Cohen &
Melendez (2005, Cat. J/AJ/129/303) (1)
113-118 F6.3 [-] [Na/Fe]CM05 ?=9.999 [Na/Fe] abundance from Cohen &
Melendez (2005, Cat. J/AJ/129/303) (1)
123-128 F6.3 [-] [O/Fe]JP12 ?=9.999 [O/Fe] abundance from Johnson &
Pilachowski (2012, Cat. J/ApJ/754/L38) (1)
133-138 F6.3 [-] [Na/Fe]JP12 ?=9.999 [Na/Fe] abundance from Johnson &
Pilachowski (2012, Cat. J/ApJ/754/L38) (1)
141 A1 --- Class Classification as from
Carretta et al. (2009, Cat. J/A+A/505/117)
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Note (1): Missing abundances are denoted with 9.999.
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Byte-by-byte Description of file: phot.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- ID Internal ID from our catalogue
9- 19 F11.7 deg RAdeg Right Ascension (J2000)
22- 31 F10.7 deg DEdeg Declination (J2000)
35- 41 F7.4 mag umag Stroemgren u magnitude
46- 51 F6.4 mag e_umag Error in u magnitude
55- 61 F7.4 mag vmag Stroemgren v magnitude
66- 71 F6.4 mag e_vmag Error in v magnitude
75- 81 F7.4 mag bmag Stroemgren b magnitude
85- 91 F7.4 mag bmagnew Recalibrated Stroemgren b magnitude
96-101 F6.4 mag e_bmag Error in b magnitude
105-111 F7.4 mag ymag Stroemgren y magnitude
116-121 F6.4 mag e_ymag Error in y magnitude
125-131 F7.4 --- chi DAOPHOT chi parameter
133-141 F9.4 --- sharp DAOPHOT sharp parameter
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Acknowledgements:
Alessandro Savino, A.savino(at)uni-heidelberg.de
History:
15-Jan-2020: on-line version
11-May-2020: Due to limited coverage of the calibration field, modest
spatial variations were present in the zero-point of the b magnitude.
We thank G. Gontcharov for making us aware of the effect. A recalibrated
b magnitude (bmagnew) has been added to the original catalogue.
(End) A. Savino [ZAH-Heidelberg, Germany], P. Vannier [CDS] 13-Jan-2020