LMCEXTOBJ - Large Magellanic Cloud Extended Objects Catalog

Overview

A survey of extended objects in the Large Magellanic Cloud (LMC) was carried out on the ESO/SERC R and J Sky Survey Atlases, checking entries in previous catalogs and searching for new objects. The census provided 6659 objects including star clusters, emission-free associations, and objects related to emission nebulae. Each of these classes contains three subclasses with intermediate properties, which are used to infer total populations. The survey includes cross-identifications among catalogs, and includes 3246 new objects (~49% of the unified catalog). The authors have provided accurate positions, classification, and homogeneous measurements of sizes and position angles, as well as information on cluster pairs and hierarchical relation for superimposed objects. This unification and enlargement of catalogs is important for future searches of fainter and smaller new objects. The present catalog together with its previous counterpart for the SMC and the inter-Cloud region provide a total population of 7847 extended objects in the Magellanic System. The angular distribution of the ensemble reveals important clues on the interaction between the LMC and SMC.

Catalog Bibcode

1999AJ....117..238B

References

A revised and extended catalog of Magellanic system clusters, associations,
and emission nebulae. II. The Large Magellanic Cloud.
       Bica E.L.D., Schmitt H.R., Dutra C.M., Oliveira H.L.
      <Astron. J. 117, 238 (1999)>
      =1999AJ....117..238B      (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in March 2007 based on the CDS table J/AJ/117/238, file table2.dat and contains the 6659 extended objects found in this LMC survey.

Parameters

Plate_Quadrant
The Sky Survey plate and quadrant where the object is best seen.

Name
The name gives the first listed cross-identification for the object from previous different catalogs, where the authors have considered as equivalent objects H II regions and their embedded stellar associations of comparable extent; some objects were separated in two or more parts and consequently the designation is complemented with "n" for northern part, "se" for southeastern part, etc. The list of LMC catalogs used for the cross-identifications and the corresponding prefixes used in their names is listed in Table 1 of the reference paper, and is available also at https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/117/238/table1.dat.gz

RA
The Right Ascension of the object in the selected equinox. This was given in J2000.0 coordinates to a precision of 1 second of time in the original table.

Dec
The Declination of the object in the selected equinox. This was given in J2000.0 coordinates to a precision of 1 arcsecond in the original table.

LII
The Galactic Longitude of the object.

BII
The Galactic Latitude of the object.

Object_Type
The extended object type following Paper I (Bica & Schmitt 1995, ApJS, 101, 41 = SMCCLUSTRS in HEASARC Browse database): the sequence C, CA, AC to A is essentially one of density, where objects with the higher density of stars are classified as C, and objects with the lower density as A. Objects NA and NC are stellar systems clearly related to emission, while N, in this particular table, refers to known supernova remnants. AN and CN are stellar systems with traces of emission.

Major_Axis
The size of the major axis of the object, in arcminutes.

Minor_Axis
The size of the minor axis of the object, in arcminutes.

Position_Angle
The position angle of the major axis of the object, in degrees, where 0 degrees = N, 90 degrees = E, etc.

Alt_Names
This field gives the second and subsequent (comma-delimited) cross-identifications listed for the object from previous different catalogs, where the authors have considered as equivalent objects H II regions and their embedded stellar associations of comparable extent; some objects were separated in two or more parts and consequently the designation is complemented with "n" for northern part, "se" for southeastern part, etc. The list of LMC catalogs used for the cross-identifications and the corresponding prefixes used in their names is listed in Table 1 of the reference paper, and is available also at https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/117/238/table1.dat.gz

Remarks
Coded remarks about the object, as follows: "mT" and "mP" indicate a member of a triple or pair, respectively. A hierarchical indication is given for objects embedded in or superimposed on larger ones, where "in" suggests a possible physical connection, while "sup" suggests a projection.

Contact Person

Questions regarding the LMCEXTOBJ database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Friday, 08-Nov-2024 14:52:16 EST