J/A+A/547/A65 Extended stellar objects in galaxies (Bruens+, 2012)
A catalog of extended clusters and ultra-compact dwarf galaxies.
An analysis of their parameters in early- and late-type galaxies.
Bruens R.C., Kroupa P.
<Astron. Astrophys. 547, A65 (2012)>
=2012A&A...547A..65B 2012A&A...547A..65B
ADC_Keywords: Galaxy catalogs ; Clusters, globular ; Associations, stellar
Keywords: catalogs - galaxies: star clusters: general -
galaxies: star clusters: individual: ECs and UCDs
Abstract:
In the last decade, very extended old stellar clusters with masses in
the range from a few 104 to 108M☉ and effective radii larger
than 10pc have been found in various types of galaxies in different
environments. Objects with masses comparable to normal globular
clusters (GCs) are called extended clusters (ECs), while objects with
masses in the dwarf galaxy regime are called ultra-compact dwarf
galaxies (UCDs). The paper analyses the observational parameters total
luminosity, MV, effective radius, reff, and projected distance to
the host galaxy, Rproj, of all known ECs and UCDs and the dependence
of these parameters on the type and the total luminosity of their host
galaxy. We searched the available literature to compile a catalog of
star clusters with effective radii larger than 10pc. As there is no
clear distinction between ECs and UCDs, both types of objects will be
called extended stellar objects - abbreviated "EOs" - in this paper.
In total, we found 813 EOs of which 171 are associated with late-type
galaxies and 642 EOs associated with early-type galaxies. EOs cover a
luminosity range from about MV=-4 to -14mag. However, the vast
majority of EOs brighter than MV=-10mag are associated with giant
elliptical galaxies. At each magnitude extended objects are found with
effective radii between 10pc and an upper size limit, which shows a
clear trend: the more luminous the object the larger is the upper size
limit. For EOs associated with early-and late-type galaxies, the EO
luminosity functions peak at -6.40mag and -6.47mag, respectively,
which is about one magnitude fainter than the peak of the GC
luminosity function. EOs and GCs form a coherent structure in the
reff vs. MV parameter space, while there is a clear gap between
EOs and early type dwarf galaxies. However, there is a small potential
overlap at the high-mass end, where the most extended EOs are close to
the parameters of some compact elliptical galaxies. We compare the EO
sample with the numerical models of a previous paper and conclude that
the parameters of the EO sample as a whole can be very well explained
by a star cluster origin, where EOs are the results of merged star
clusters of cluster complexes (CCs).
Description:
The table contains the catalog of the 813 EOs presented in this paper.
For each EO, a running number, the designation of EO in this paper
(name of galaxy + EO + number), an alternative name or designation in
a previous paper, the effective radius of the EO, the absolute V-band
luminosity of the EO, the projected distance to the host galaxy (for
the Milky Way the galactocentric distance is used), and the references
to the publications are given in the catalog.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
galaxies.dat 57 65 Galaxy positions
table1.dat 66 813 Parameters of 813 extended stellar objects
refs.dat 80 51 References
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See also:
VII/195 : Globular Clusters in the Milky Way (Harris, 1996)
J/MNRAS/327/1116 : VI photometry of Sombrero globular clusters (Larsen+, 2001)
J/A+A/442/85 : Globular cluster cand. in low SB galaxies (Sharina+, 2005)
J/A+A/455/453 : Globular Cluster System of NGC5846 (Chies-Santos+, 2006)
J/ApJ/671/1624 : NGC 1533 globular cluster candidates (Degraaff+, 2007)
J/A+A/472/111 : Centaurus Compact Object Survey (Mieske+, 2007)
J/A+A/467/1003 : Photometry of star clusters in NGC 1380 (Chies-Santos+ 2007)
J/AJ/135/1567 : Bright star clusters in M51 (Hwang+, 2008)
J/AJ/136/2295 : Ultra-compact dwarf cand. in Abell S0740 (Blakeslee+, 2008)
J/MNRAS/392/879 : Globular clusters in nearby dwarf galaxies (Georgiev+, 2009)
J/MNRAS/392/L55 : Globular clusters in M31 from K-band phot. (Peacock+, 2009)
J/A+A/503/87 : BVI phot. of NGC3370 star cluster cand. (Cantiello+, 2009)
J/A+A/525/A19 : Photometry of globulars in early gal. (Chies-Santos+, 2011)
J/A+A/531/A4 : Ultra compact dwarfs and globulars in Hya I (Misgeld+, 2011)
J/MNRAS/420/37 : NGC 4365 globular clusters (Blom+, 2012)
Byte-by-byte Description of file: galaxies.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh ? Simbad Right ascension (J2000)
4- 5 I2 min RAm ? Simbad Right ascension (J2000)
7- 11 F5.2 s RAs ? Simbad Right ascension (J2000)
15 A1 --- DE- Simbad Declination sign (J2000)
16- 17 I2 deg DEd ? Simbad Declination (J2000)
19- 20 I2 arcmin DEm ? Simbad Declination (J2000)
22- 25 F4.1 arcsec DEs ? Simbad Declination (J2000)
29- 41 A13 --- SName Simbad name of the galaxy
47- 57 A11 --- Name Galaxy name, as in table1
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Running number of extended stellar object (EO)
5- 20 A16 --- Name Name of extended stellar object
22- 42 A21 --- OName Alternative name or designation of extended
stellar object
44- 47 F4.1 pc reff Effective Radius of extended stellar object
49- 54 F6.2 mag VMAG Absolute V-band magnitude of
extended stellar object
56- 60 F5.1 kpc Rproj ? Projected distance from host galaxy (1)
62- 66 A5 --- Ref Reference to the publication of the data,
in refs.dat file
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Note (1): For the extended stellar objects of the Milky Way the
galacto-centric distance is used.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode BibCode
24- 45 A22 --- Aut Author's name
47- 80 A34 --- Com Comments
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Acknowledgements:
Renate Bruens, rcbruens(at)astro.uni-bonn.de
(End) Patricia Vannier [CDS] 24-Sep-2012