J/MNRAS/448/42 Equivalent widths and atomic data for GCs (Lamb+, 2015)
Chemical abundances in the globular clusters NGC 5024 and NGC 5466 from optical
and infrared spectroscopy.
Lamb M.P., Venn K.A., Shetrone M.D., Sakari C.M., Pritzl B.J.
<Mon. Not. R. Astron. Soc., 448, 42-58 (2015)>
=2015MNRAS.448...42L 2015MNRAS.448...42L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Spectroscopy ; Equivalent widths
Keywords: techniques: spectroscopic - stars: abundances -
globular clusters: individual: NGC 5024 -
globular clusters: individual: NGC 5466
Abstract:
Detailed chemical abundances for five stars in two Galactic globular
clusters, NGC 5466 and NGC 5024, are presented from high-resolution
optical (from the Hobby-Eberley Telescope) and infrared spectra (from
the SDSS-III APOGEE survey). We find [Fe/H]=-1.97±0.13 dex for
NGC 5466, and [Fe/H]=-2.06±0.13 dex for NGC 5024, and the typical
abundance pattern for globular clusters for the remaining elements,
e.g. both show evidence for mixing in their light element abundance
ratios (C, N), and asymptotic giant branch contributions in their
heavy element abundances (Y, Ba, and Eu). These clusters were selected
to examine chemical trends that may correlate them with the Sgr dwarf
galaxy remnant, but at these low metallicities no obvious differences
from the Galactic abundance pattern are found. Regardless, we compare
our results from the optical and infrared analyses to find that oxygen
and silicon abundances determined from the infrared spectral lines are
in better agreement with the other α-element ratios and with
smaller random errors.
Description:
Optical spectra were gathered with the High Resolution Spectrograph
(HRS; Tull 1998, Proc. SPIE, 3355, 387) on the HET. The HRS was
configured at resolution R=30000 with 2x2 pixel binning using the
2 arcsec fibre. The HRS splits the incoming beam on to two CCD chips,
from which the spectral regions 6000-7000 Å (red chip) and
4800-5900 Å (blue chip) were extracted for this work. Two standard
stars were also observed, RGB stars with previously published spectral
analyses in each of the GCs M3 and M13.
Objects:
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RA (ICRS) DE Designation(s)
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13 12 55.25 +18 10 05.4 NGC 5024 = M 53
14 05 27.29 +28 32 04.0 NGC 5466 = GCl 27
13 42 11.62 +28 22 38.2 M3 = GCl 25
16 41 41.63 +36 27 40.7 M13 = GCl 45
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 75 7 The sample of stars observed in the optical
with the HET
table2.dat 68 372 Equivalent Widths and Atomic Data
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See also:
I/278 : Catalog of stars in M3 (von Zeipel, 1908)
J/A+A/320/757 : M3 stars CCD photometry (Ferraro+ 1997)
J/PAZh/23/454 : Identification and coordinates in M 53 (Evstigneeva+, 1997)
J/AJ/122/3219 : M3 and M13 CCD BV photometry (Rey+, 2001)
J/AJ/129/303 : Abundances of stars in M3 and M13 (Cohen+, 2005)
J/ApJ/638/1018 : Equivalent widths for giant stars in M13 and M71
(Yong+, 2006)
J/ApJ/663/277 : BVI of NGC 5466 red giants and blue stragglers
(Fekadu+, 2007)
J/AJ/137/4282 : Red giant stars in clusters. II. M13 and M92
(Meszaros+, 2009)
J/ApJ/754/L38 : Abundances and radial velocities of M13 giants
(Johnson+, 2012)
J/MNRAS/424/2722 : Variable stars in NGC 5024 (M53) (Bramich+, 2012)
J/ApJ/824/5 : Chemical abundances in NGC 5024 (M53) (Boberg+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Star Star name
16- 17 I2 h RAh Hour of Right Ascension (J2000)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 26 F5.2 s RAs Second of Right Ascension (J2000)
28 A1 --- DE- Sign of the Declination (J2000)
29- 30 I2 deg DEd Degree of Declination (J2000)
32- 33 I2 arcmin DEm Arcminute of Declination (J2000)
35- 38 F4.1 arcsec DEs Arcsecond of Declination (J2000)
40- 44 A5 "month" Obs.M Month of observation
46- 49 I4 yr Obs.Y Year of observation
51- 54 I4 s Texp Total exposure time
56 I1 --- Night [1/3] Number of nights that observation was
taken
58- 59 I2 --- S/Nred [50/85] Signal-to-noise ratio at 6250Å
61- 62 I2 --- S/Nblue [40/75] Signal-to-noise ratio at 5500Å
64- 70 F7.2 km/s HV Heliocentric velocity
72- 75 F4.2 km/s e_HV Uncertainty in HV
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Ion Element and ionization state
7- 13 F7.2 0.1nm lambda Spectral line wavelength (Å)
15- 18 F4.2 eV EP Excitation Potential
20- 26 F7.3 [-] loggf Oscillator strength
28- 32 F5.1 0.1pm EW22254 ? Equivalent width for star NGC 5024-22254 (mÅ)
34- 38 F5.1 0.1pm EW50371 ? Equivalent width for star NGC 5024-50371 (mÅ)
40- 44 F5.1 0.1pm EW1344 ? Equivalent width for star NGC 5466-1344 (mÅ)
46- 50 F5.1 0.1pm EW9951 ? Equivalent width for star NGC 5466-9951 (mÅ)
52- 56 F5.1 0.1pm EW10186 ? Equivalent width for star NGC 5466-10186 (mÅ)
58- 62 F5.1 0.1pm EWM3 ? Equivalent width for star M3-C41303-2217 (mÅ)
64- 68 F5.1 0.1pm EWM13 ? Equivalent width for star M13-III-18 (mÅ)
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 13-Nov-2017