J/A+A/440/901 Reddening and metallicity of NGC 6752 (Gratton, 2005)
Precise reddening and metallicity of NGC 6752 from FLAMES spectra.
Gratton R.G., Bragaglia A., Carretta E., De Angeli F., Lucatello S.,
Momany Y., Piotto G., Recio Blanco A.
<Astron. Astrophys. 440, 901 (2005)>
=2005A&A...440..901G 2005A&A...440..901G
ADC_Keywords: Clusters, globular ; Photometry, UBV ; Abundances ; Reddening ;
Effective temperatures ; Radial velocities ; Equivalent widths
Keywords: stars: abundances - stars: evolution - stars: Population II -
Galaxy: globular clusters: general - Galaxy: formation
Abstract:
Accurate reddenings for Globular Clusters could be obtained by
comparing the colour-temperature obtained using temperatures from
reddening-free indicator (Hα), with that given by standard
colour-temperature calibrations. The large multiplexing opportunity
offered by FLAMES at VLT2 allowed us to obtain spectra centered on
Hα at a resolution of R=6000 and 5<S/N<50 for 120 stars near the
turn-off of NGC 6752 with GIRAFFE from a single 1300 seconds exposure
on June 24th, 2004.
Description:
Table 3 contains the relative flux in the bands around Hα
measured on FLAMES GIRAFFE spectra of about 120 stars near the
Turn-Off of NGC 6752.
Table 4 contains V magnitudes, B-V colours, effective temperatures
(derived from the wings of the Hα lines), and reddenings E(B-V)
from the same stars.
Table 7 contains the equivalent widths measured on UVES spectra of
seven stars at the RGB bump of NGC 6752, used to derive precise metal
abundances for the cluster.
Objects:
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RA (2000) DE Designation(s)
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19 10 51.8 -59 58 55 NGC 6752 = GCl 108 = C 1906-600
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 66 120 S/N ratios, heliocentric radial velocities and
normalized fluxes for the target stars
table4.dat 34 120 Temperatures and reddenings
table7.dat 68 65 Equivalent widths from UVES spectra
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See also:
J/ApJS/99/637 : Equivalent widths for 54 red giants (Norris+ 1995)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq Sequential number of the star
8- 9 I2 --- S/N Signal-to-noise ratio
12- 16 F5.1 km/s HRV Heliocentric radial Velocity
18- 23 F6.3 --- Flux3 Normalized flux in band 3, 6547.8-6552.8Å
25- 30 F6.3 --- Flux4 Normalized flux in band 4, 6552.8-6557.8Å
32- 37 F6.3 --- Flux5 Normalized flux in band 5, 6557.8-6562.8Å
39- 44 F6.3 --- Flux6 Normalized flux in band 6, 6562.8-6567.8Å
46- 51 F6.3 --- Flux7 Normalized flux in band 7, 6567.8-6572.8Å
53- 58 F6.3 --- Flux8 Normalized flux in band 8, 6572.8-6577.8Å
60- 65 F6.3 --- <Flux5,6> Average of fluxes in bands 5 and 6
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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- 5 I5 --- Seq Sequential number of the star
8- 13 F6.3 mag Vmag V magnitude
16- 20 F5.3 mag B-V B-V colour index
22- 25 I4 K Teff Effective Temperature
28- 33 F6.3 mag E(B-V) Reddening
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 4 F4.1 --- El Element
6- 12 F7.2 0.1nm Lambda Line Wavelength
15- 18 F4.2 eV EP Excitation Potential
21- 25 F5.2 --- loggf log Oscillator Strength
27- 31 F5.1 0.1pm EW25072 ? Equivalent width for star 25072
33- 37 F5.1 0.1pm EW26529 ? Equivalent width for star 26529
39- 43 F5.1 0.1pm EW30409 ? Equivalent width for star 30409
45- 49 F5.1 0.1pm EW30426 ? Equivalent width for star 30426
51- 55 F5.1 0.1pm EW34854 ? Equivalent width for star 34854
57- 61 F5.1 0.1pm EW37999 ? Equivalent width for star 37999
63 A1 --- l_EW39672 Limit flag on EW39672
64- 68 F5.1 0.1pm EW39672 ? Equivalent width for star 39672
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Acknowledgements: Raffaele Gratton, gratton(at)pd.astro.it
Remarks: the paper indicates the existence of an accurate astrometry,
but it has not been possible to get it from any of the authors.
(End) Patricia Vannier [CDS] 10-Jun-2005