J/A+A/405/111 LMC Survey of Young Stellar Systems (Gouliermis+, 2003)
OB stellar associations in the Large Magellanic Cloud:
Survey of young stellar systems.
Gouliermis D., Kontizas M., Kontizas E., Korakitis R.
<Astron. Astrophys. 405, 111 (2003)>
=2003A&A...405..111G 2003A&A...405..111G
ADC_Keywords: Magellanic Clouds ; Surveys ; Clusters, open ;
Associations, stellar
Keywords: galaxies: individual: LMC - galaxies: star clusters -
galaxies: stellar content - surveys
Abstract:
The method developed by Gouliermis et al. (2000AJ....119.1737G 2000AJ....119.1737G),
for the detection and classification of stellar systems in the
LMC, was used for the identification of stellar associations and open
clusters in the central area of the LMC. This method was applied on
the stellar catalog produced from a scanned 1.2m UK Schmidt Telescope
Plate in U with a field of view almost 6.5degx6.5deg, centered on the
Bar of this galaxy. The survey of the identified systems is presented
here followed by the results of the investigation on their spatial
distribution and their structural parameters, as were estimated
according to our proposed methodology. The detected open clusters and
stellar associations show to form large filamentary structures, which
are often connected with the loci of HI shells. The derived mean size
of the stellar associations in this survey was found to agree with the
average size found previously by other authors, for stellar
associations in different galaxies. This common size of about 80pc
might represent a universal scale for the star formation process,
whereas the parameter correlations of the detected loose systems
support the distinction between open clusters and stellar
associations.
Description:
Structural parameters for 412 newly detected young stellar systems in
the central area of LMC are presented. From them 259 were classified
as `intermediate' and 153 as `unbound' systems, according to their
central stellar density. The intermediate systems represent mostly
open clusters, while the unbound are stellar associations. The set of
parameters given here includes the positions of the systems, their
dimensions, half-mass and Spitzer radii, as well as their estimated
total masses and central densities (within their half-mass radii).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog1.dat 69 259 Parameters for the detected intermediate systems
catalog2.dat 69 153 Parameters for the detected unbound systems
table3.dat 153 640 Catalog of objects found by SIMBAD located in
areas covered by the intermediate and
unbound systems of this survey
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Byte-by-byte Description of file: catalog?.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- ID ID number (1)
7- 8 I2 h RAh Right ascension (J2000)
10- 13 F4.1 min RAm Right ascension (J2000)
16 A1 --- DE- Declination sign (J2000)
17- 18 I2 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 25 I3 pc Size Size of each system
27- 30 I4 --- NStar Number of counted stars
32- 34 I3 --- e_NStar Mean error of number of counted stars
37- 40 F4.1 pc rsp Spitzer radius
43- 46 F4.1 pc rh Half-mass radius
49- 52 F4.1 ksolMass MassMin Minimum estimated mass
54- 57 F4.1 ksolMass MassMax Maximum estimated mass
60- 63 F4.2 solMass/pc3 dens Central stellar density
66- 69 F4.2 solMass/pc3 e_dens Mean error of central stellar density
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Note (1): The ID of each system consists of one character followed
by four digits.
For the intermediate systems (catalog1.dat) we used the character
`O' from `Open clusters'.
For the unbound systems (catalog2.dat) we used the character
`A' from `Associations'.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- ID Identification
6- 28 A23 --- SName Simbad Name
30-128 A99 ---- RObjects Additional related objects
130-131 I2 h RAh Right ascension (J2000)
133-134 I2 min RAm Right ascension (J2000)
136-137 I2 s RAs Right ascension (J2000)
139 A1 --- DE- Declination sign (J2000)
140-141 I2 deg DEd Declination (J2000)
143-146 F4.1 arcmin DEm Declination (J2000)
149-152 A4 --- Type Type of object
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Acknowledgements: Dimitrios Gouliermis
History:
* 24-Oct-2003: table3 was added (kindly supplied by the author)
(End) Dimitrios Gouliermis [Sternwarte Bonn], Patricia Bauer [CDS] 17-Jun-2003