J/MNRAS/481/918 Spatial distribution of GCs in the Galaxy (Arakelyan+, 2018)
Spatial distribution of globular clusters in the Galaxy.
Arakelyan N.R., Pilipenko S.V., Libeskind N.I.
<Mon. Not. R. Astron. Soc., 481, 918-929 (2018)>
=2018MNRAS.481..918A 2018MNRAS.481..918A (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Milky Way ; Optical
Keywords: globular clusters: general - Galaxy: structure
Abstract:
The Milky Way's satellite galaxies and globular clusters (GCs) are
known to exhibit an anisotropic spatial distribution. We examine in
detail this anisotropy by the means of the inertia tensor. We estimate
the statistical significance of the results by repeating this analysis
for random catalogues that use the radial distribution of the real
sample. Our method reproduces the well-known planar structure in the
distribution of the satellite galaxies. We show that for GCs several
anisotropic structures are observed. The GCs at small distances,
2<R<10kpc, show a structure coplanar with the Galactic plane. At
smaller and larger distances, the whole sample of GCs shows quite weak
anisotropy. Nevertheless, at largest distances the orientation of the
structure is close to that of the satellite galaxies, i.e.
perpendicular to the Galactic plane. We estimate the probability of
random realization for this structure of 1.7 per cent. The bulge-disc
GCs show a clear disc-like structure lying within the Galactic disc.
The old halo GCs show two structures: a well-pronounced polar
elongated structure at R<3kpc that is perpendicular to the Galactic
plane, and a less pronounced disc-like structure coplanar with the
Galactic disc at 6<R<20kpc. The young halo GCs do not show significant
anisotropy.
Description:
Our Galaxy contains at least 157 GCs (Harris, Harris & Alessi
2013ApJ...772...82H 2013ApJ...772...82H, Cat. J/ApJ/772/82), and 27 SGs (the number of SGs
of the local group is 53; McConnachie 2012AJ....144....4M 2012AJ....144....4M, Cat.
J/AJ/144/4). The catalogues we use are presented in Tables 1 and 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 34 157 Catalogue of 157 Galactic GCs coordinates and
types compiled from Harris et al.
(2013ApJ...772...82H 2013ApJ...772...82H, Cat. J/ApJ/772/82) and
Mackey & van den Bergh (2005MNRAS.360..631M 2005MNRAS.360..631M)
table2.dat 32 27 Catalogue of 27 Milky Way SGs extracted from
McConnachie (2012AJ....144....4M 2012AJ....144....4M,
Cat. J/AJ/144/4)
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See also:
J/ApJ/772/82 : A catalog of globular cluster systems (Harris+, 2013)
J/AJ/144/4 : Properties of dwarf galaxies in the Local Group
(McConnachie+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Globular cluster name
13- 18 F6.2 deg GLON Galactic longitude
20- 25 F6.2 deg GLAT Galactic latitude
27- 31 F5.1 kpc Dist Distance from the Sun
33- 34 A2 --- Type Type, according to Mackey & van den Bergh
(2005MNRAS.360..631M 2005MNRAS.360..631M) (1)
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Note (1): Type as follows:
BD = the bulge/disc clusters (37 objects)
OH = the old halo clusters (70 objects)
YH = the young halo clusters (30 objects)
SG = clusters belonging to the Sagittarius dwarf (six objects)
UN = clusters whose membership type remains unknown due to insufficient or
unclassifiable data (seven objects)
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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- 16 A16 --- Name Satellite galaxy name
18- 22 F5.1 deg GLON Galactic longitude
24- 28 F5.1 deg GLAT Galactic latitude
30- 32 I3 kpc Dist Distance from the Sun
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 07-Jun-2022