CDS Portal Simbad VizieR Aladin X-Match Other Help J/MNRAS/438/3507 NGC 5824 calcium triplet equivalent widths (Da Costa+, 2014) NGC 5824: a luminous outer halo globular cluster with an intrinsic abundance spread. Da Costa G.S., Held E.V., Saviane I. =2014MNRAS.438.3507D (SIMBAD/NED BibCode) ADC_Keywords: Clusters, globular ; Radial velocities ; Equivalent widths Keywords: stars: abundances - stars: Population II - globular clusters: general - globular clusters: individual: NGC 5824 Abstract: We present a detailed study of the strengths of the calcium triplet absorption lines in the spectra of a large sample of red giant members of the luminous outer Galactic halo globular cluster NGC 5824. The spectra were obtained with the FORS2 and GMOS-S multi-object spectrographs at the VLT and the Gemini-S telescope, respectively. By comparing the line strengths of the NGC 5824 stars with those for red giants in clusters with well-established abundances, we conclude that there is an intrinsic abundance dispersion in NGC 5824 characterized by an inter-quartile range in [Fe/H] of 0.10dex and a total range of ∼0.3dex. As for ω Cen and M22, the abundance distribution shows a steep rise on the metal-poor side and a shallower decline on the metal-rich side. There is also some indication that the distribution is not unimodal with perhaps three distinct abundance groupings present. NGC 5824 has a further unusual characteristic: the outer surface density profile shows no signs of a tidal cutoff. Instead, the profile has a power-law distribution with cluster stars detected to a radius exceeding 400pc. We postulate that NGC 5824 may be the remnant nuclear star cluster of a now disrupted dwarf galaxy accreted during the formation of the Galaxy's halo. We further speculate that the presence of an intrinsic [Fe/H] spread is the characteristic that distinguishes former nuclear star clusters from other globular clusters. Description: Observing time to follow up the possibility of an intrinsic [Fe/H] spread in NGC 5824 was allocated for intermediate-resolution spectroscopy of candidate red giant members on both the VLT with the FORS2 multi-object spectrograph, and on the Gemini-S telescope with the GMOS-S multi-object spectrograph. File Summary: FileName Lrecl Records Explanations ReadMe 80 . This file table1.dat 73 190 NGC 5824 stars observed Byte-by-byte Description of file: table1.dat Bytes Format Units Label Explanations 1- 8 I8 --- ID Star identification number 10- 18 F9.5 deg RAdeg Right ascension (J2000) 20- 28 F9.5 deg DEdeg Declinaiton (J2000) 30- 35 F6.3 mag Vmag V magnitude 37- 41 F5.3 mag V-I V-I colour index 43- 46 I4 km/s RV Radial velocity 48- 51 F4.2 0.1nm Sum(W) Ca 8542Å and 8862Å lines equivalent widths sum (W8542+W8862) 53- 56 F4.2 0.1nm e_Sum(W) rms uncertainty on Sum(W) 58- 61 F4.2 0.1nm W8807 ? Ca 8807Å line equivalent width 63- 66 F4.2 0.1nm e_W8807 ? rms uncertainty on W8807 68 I1 --- NF Number of observations with FORS2 at the VLT 70 I1 --- NG Number of observations with GMOS-S at Gemini South 72- 73 A2 --- Class Class code (1) Note (1): Class code as follows: MR = star is member of the final RGB sample MA = stars in the final AGB member sample NM = probable non-member of the cluster. History: From electronic version of the journal (End) Patricia Vannier [CDS] 13-Jun-2016 The document above follows the rules of the Standard Description for Astronomical Catalogues; from this documentation it is possible to generate f77 program to load files into arrays or line by line © Université de Strasbourg/CNRS • Contact