SHKGALAXY - Shakhabazian (Shk) Compact Groups of Galaxies: Individual Galaxies Data

Overview

The largest survey of compact galaxy groups was published by Shakhbazian et al. (the CDS catalog VII/89, implemented by the HEASARC as the SHK database table). This present catalog provides accurate positions of the individual galaxies in the groups; photometric properties of the Southern sky (delta not greater than +2.5 degrees) are evaluated on the basis of the COSMOS/UKST catalog of the Southern sky.

This catalog contains 373 groups; this number differs from the number in Shakhbazian's list (377 groups) by the following: (i) there are no data for groups 001 (already published by other authors), 206 and 241 (could not be re-identified), 252 (this is identical with 214), 301 and 353 (could not be re-identified); (ii) Group 328 was published twice (in North and South); and (iii) Group 340 was divided in two parts (340 and 340a), according to Bettoni and Fasano ([BF95]=1995AJ....109...32B).

This HEASARC version of the catalog contains a total of 3435 individual galaxies identified as members of the compact groups, 2574 from the northern part of this survey (taken from the ADS Catalog VII/196 file north.dat), and 861 from the southern part of this survey (extracted from the 10746 entries in the ADS Catalog VII/196 file south.dat by including only entries corresponding to bona fide group members).

Catalog Bibcodes

1993AN....314..225S
1993AN....314..317S
1994AN....315...11S
1994AN....315...97S
1996AN....317..239S
1996AN....317..315S
1996AN....317..383S
1997AN....318....7S
1997AN....318...89S
1997AN....318..149S
1998yCat.7196....0S

References

Photometry of Shakhbazian Groups I-X, Stoll D., Tiersch H., Braun M., and Cordis L. in various issues of Astron. Nachr. (314, 225; 314, 317; 315, 11; 311, 97; 317, 239; 317, 315; 317 383; 318, 7; 318, 89; 318, 149), published from 1993 to 1997.

Provenance

This database table was created by the HEASARC in June, 2000, based on the CDS Catalog VII/196 (files north.dat and south.dat).

Notes

Some individual notes (mostly alternate names for the Shakhbazian Compact Groups) on some of the northern groups (in north.dat):

SHK 003 = VV 153 = MCG +09-19-19a
    005 = HGC 050
    006 = A 1218
    016 = I Zw 167, ARP 330
    019 = VV 678, MCG +03-34-039
    026 = A 1143
    038 = III Zw 022
    040 = A 0193
    053 = A 1050
    054 = A 1067
    065 = A 1284
    078 : probably stars
    166 = UGC 10638, part of A 2247
    191 = A 1097
    219 = A 1984
    233 = A 1082?
    360 = A 2113
    361 = A 2524
    362 = III Zw 108

Some individual notes on some of the southern groups (in south.dat):

1 The objects of the group were not marked in the figure of the paper of
1 Shakhbazian (1973Afz.....9..495S, Cat. <VII/89>).  So the numbering was done
1 by the authors.
2 Object Shk 30-2 seems to be a double object on both Palomar prints
3 Object Shk 30-5 is projected onto the group (Amirkhanian,
3 1989SoByu..61...25A)
4 Object Shk 30-1 has a magnitude m_V=14.0s (Amirkhanian 1989SoByu..61...25A)
5 Object Shk 30-2 has a magnitude m_V=14.84s (Amirkhanian
5 1989SoByu..61...25A)
6 Object Shk 30-3 has a magnitude m_V=14.44s (Amirkhanian
6 1989SoByu..61...25A)
7 Object Shk 30-4 has a magnitude m_V=16.04s (Amirkhanian
7 1989SoByu..61...25A)
8 Object Shk 30-6 has a magnitude m_V=17.10s (Amirkhanian
8 1989SoByu..61...25A)
9 Object Shk 32-9 seems to be a star
10 According to the red Palomar print, object Shk 33 3 seems to be a double
10 object and so it was designated as Nr.3 and 4.
11 Object Shk 269-11 seems to be a double object (11+13) on the Palomar prints
12 Object Shk 276-10 is situated between object Shk 276-2 and Shk 276-4. It
12 cannot be distinguished on the plates of the UK Schmidt.
13 Object Shk 278-2 seems to be a double object (2+7) on the Palomar prints
14 The object (Shk 279-2, Shk 283-4, Shk 286-1) seems to be a single object on
14 the Palomar prints, but two objects can be clearly distinguisehd on the
14 plates of the UK Schmidt.
15 The object (Shk 290-7, Shk 290-21, Shk 291-11, Shk 295-4, Shk 302-9, Shk
15 312-4) cannot be found on the plates of the UK Schmidt, but may be it is a
15 mistaking on the Palomar prints.
16 Objects (Shk 292-7 and Shk 292-14; Shk 297-4 and Shk 297-10; Shk 299-6 and
16 Shk 299-12; Shk 303-7 and Shk 303-11) can be clearly distinguished on the
16 Palomar prints, but are only one object on the UKST plates.
17 Object (Shk 317-4, Shk 323-6, Shk 328-3, Shk 328-4, Shk 328-5, Shk 328-7,
17 Shk 331-6) is clearly seen on the Palomar prints, but not seen on the plates
17 of the UK Schmidt.
18 Objects Shk 334-2 and Shk 334-5 seem to be a single object on the Palomar
18 prints, but two objects can clearly be distinguished on the plates of the UK
18 Schmidt.
19 For Shk 310, in the original Baier and Tiersch chart (1978, Cat. <VII/89>)
19 there are twice #8 and 9. We named the northerly #9 as 12 and the northerly
19 #8 as 13. On the UK plates the objects #10, 11, 13 are missing.

Parameters

Shk
The number of the Shakhbazian Compact Group to which the galaxy belongs.

Name
The name of the galaxy derived by combining the Shakhbazian Compact Group number (shk), a flag (shk_flag) used to distinguish two compact groups SHK 340 and SHK 340A that are now considered to be separate entities, and the number of the galaxy in the Shakhbazian Compact Group (shk_galaxy), according to the standard astronomical nomenclature convention.

RA
The Right Ascension of the galaxy in the specified equinox. Notice that the RA was given to a precision of 0.1 seconds of time and that the equinox was J2000 in the CDS Catalog from which the present database was constructed.

Dec
The Declination of the galaxy in the specified equinox. Notice that the Declination was given to a precision of 1 arcsecond and that the equinox was J2000 in the CDS Catalog from which the present database was constructed.

LII
The galactic longitude of the galaxy.

BII
The galactic latitude of the galaxy.

Position_Source
The origin of the quoted position; in general, the coordinates of the groups were calculated from the Digitized Sky Survey (DSS), with the northern part (north.dat groups) being derived from the Palomar Observatory Sky Survey, and the southern part (south.dat groups) being derived from COSMOS/UK Schmidt Telescope. A value of 'H' for this parameter indicates that the positions were adopted from the Hamburg Quasar Survey, while a question mark '?' indicates an inaccurate position (and more information is generally given in the note parameter.

Position_Angle
The position angle of the major axis of the galaxy in degrees, in the usual sense, i.e, eastwards from North. In those cases where the ellipticity is zero, and hence it is not possible to define a position angle, it is set to a value of 999. Information on this parameter is available only for the southern (south.dat) groups.

Shk_Flag
A flag set to 'A' so as to distinguish two compact groups SHK 340 and SHK 340A that are now considered to be separate entities (cf. Bettoni and Fasano 1995, AJ, 109, 32).

Shk_Galaxy
The running number of the galaxy within the Shakhbazian Compact Group.

Shk_Galaxy_Flag
A Multiplicity index used for a few cases where galaxies may be split into two separate objects 'A' and 'B'.

Star_Flag
A flag for northern galaxies which is set to a value of `S` to indicate cases where the object is probably a star rather than a galaxy.

Vmag
The V-magnitude (only provided for galaxies in the north.dat sample).

Rmag
The R-magnitude (only provided for galaxies in the north.dat sample).

Bjg_Mag
The photographic plate system (b_j) magnitude calculated assuming the object is a galaxy (only provided for galaxies in the south.dat sample).

Bjs_Mag
The photographic plate system (b_j) magnitude calculated assuming the object is a star (only provided for galaxies in the south.dat sample).

Radial_Velocity
The radial velocity of the galaxy in km/sec (only provided for galaxies in the north.dat sample).

Redshift
The redshift of the galaxy (only provided for galaxies in the north.dat sample). When only the radial velocity V was given in the original paper, the redshift z has been calculated using the relation z = V/299792.

Semi_Major_Axis
The semi-major axis of the galaxy in arcminutes (only provided for galaxies in the south.dat sample).

Ellipticity
The ellipticity (1-b/a) of the galaxy, where b is the semi-minor axis and a is the semi-major axis (only provided for galaxies in the south.dat sample).

Number_Pixels
The number of pixels within the image of the object (only provided for galaxies in the south.dat sample).

Cosmos_Type
An automated classification type: 'S' for star-like image, 'G' for galaxy-like, and 'F' for faint or not classifiable (only provided for galaxies in the south.dat sample).

Note
This field contains either a comment or note on another name, or one or more integers referring to individual notes detailed in the Notes Section of this help file.

Class
The Browse classification of the object: all objects have been given a generic class of 'GALAXY', except for objects with a value of the parameter star_flag of 'S' which have been given a generic class of 'STAR'.

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:34:53 EDT