J/MNRAS/446/3130 NGC5694 radial velocities and metallicities (Bellazzini+, 2015)
Kinematics of a globular cluster with an extended profile: NGC 5694.
Bellazzini M., Mucciarelli A., Sollima A., Catelan M., Dalessandro E.,
Correnti M., D'orazi V., Cortes C., Amigo P.
<Mon. Not. R. Astron. Soc., 446, 3130-3138 (2015)>
=2015MNRAS.446.3130B 2015MNRAS.446.3130B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Radial velocities ; Abundances, [Fe/H]
Keywords: stars: abundances - globular clusters: individual: NGC 5694
Abstract:
We present a study of the kinematics of the remote globular cluster
NGC 5694 based on GIRAFFE@VLT medium-resolution spectra. A sample of
165 individual stars selected to lie on the red giant branch in the
cluster colour-magnitude diagram was considered. Using radial velocity
and metallicity from Calcium triplet, we were able to select 83 bona
fide cluster members. The addition of six previously known members
leads to a total sample of 89 cluster giants with typical
uncertainties ≤1.0km/s in their radial velocity estimates. The sample
covers a wide range of projected distances from the cluster centre,
from ∼0.2arcmin to 6.5arcmin ≃23 half-light radii (rh). We find
only very weak rotation, as typical of metal-poor globular clusters.
The velocity dispersion gently declines from a central value of
σ=6.1km/s to σ≃2.5km/s at ∼2arcmin≃7.1rh, then it
remains flat out to the next (and last) measured point of the
dispersion profile, at ∼4arcmin ≃14.0rh, at odds with the
predictions of isotropic King models. We show that both isotropic
single-mass non-collisional models and multimass anisotropic models
can reproduce the observed surface brightness and velocity dispersion
profiles.
Description:
The data have been acquired with the multi-object facility FLAMES@VLT
in the combined MEDUSA+UVES mode, allowing the simultaneous allocation
of 8 UVES high-resolution fibres and 132 MEDUSA mid-resolution fibres.
Two configurations of target stars have been used. A total of four
exposures of 46 min each for each configuration has been secured in
Service Mode during the period between 2012 April and July. A small
overlap between the two configurations (12 stars) has been secured in
order to cross-check the stability of the RV when measured with
different fibres.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 81 165 Main parameters for target stars observed with
FLAMES
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See also:
J/A+AS/82/71 : Deep photometry of NGC 5694 and Terzan 8 (Ortolani+, 1990)
J/MNRAS/435/3667 : Equivalent widths of 6 NGC5694 stars (Mucciarelli+, 2013)
J/AJ/135/836 : Calcium triplet index in LMC stars (Carrera+, 2008)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID ID number
6- 16 F11.7 deg RAdeg Right ascension (J2000)
18- 28 F11.7 deg DEdeg Declination (J2000)
30- 32 I3 --- SNR Signal-to-noise ratio per pixel (@8550Å)
34- 39 F6.3 mag Bmag B magnitude (1)
41- 46 F6.3 mag Vmag V magnitude (1)
48- 54 F7.2 km/s RV Radial velocity
56- 59 F4.2 km/s e_RV rms uncertainty on RV
61- 65 F5.2 [-] [Fe/H]Fe ?=- Metallicity [Fe/H] from direct FeI
lines measurement
67- 70 F4.2 [-] e_[Fe/H]Fe ? rms uncertainty on [Fe/H]Fe
72- 76 F5.2 [-] [Fe/H]CaT Metallicity [Fe/H] from Ca II triplet lines
78- 81 F4.2 [-] e_[Fe/H]CaT rms uncertainty on [Fe/H]CaT (2)
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Note (1): From Correnti et al., 2011MNRAS.417.2411C 2011MNRAS.417.2411C.
Note (2): Uncertainties in [Fe/H]CaT include both internal errors and the
uncertainty in the calibration by Carrera et al.
(2008AJ....135..836C 2008AJ....135..836C, Cat. J/AJ/135/836).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 26-Jun-2015