Abell Galaxy Clusters - 2,712 entries
compiled June 2007
Because the data does not
contain DECLINATION seconds only good to the MINUTE the positions are not
very precise. However, keep in mind this is a CLUSTER of galaxies so there
really isn't and EXACT position anyway. Garbage in Garbage out.
DOWNLOAD -
164K the ZIPPED file and UNZIP the contents into the default SDB's folder. Actually the files can be
placed anywhere on your system. The default SDB folder just makes sense. REPLACE
the existing text and SDB file "Abell Galaxy Clusters" with the newly compiled
versions! That is OVERWRITE the non-functioning version.
\TheSky6\Data\User\SDB's
Once the SDB and text file have been UNZIPPED the
SDB can be added to the Active List of SDB's using the Data | Database Manager's
"Add" button highlighted below.
Data | Sky Database Manager
Click "Add" after finding the SDB by name
Add the
downloaded and expanded SDB file named "Abell Galaxy Clusters.SDB".
To search for a cluster use
Edit | Find followed by Abell Galaxy Clusters NUMBER. See example below.
Edit | Find
Abell Galaxy Clusters NUMBER to SEARCH
Or, EXPAND the
Sky Databases (SDB's) group then Expand Abell Galaxy Clusters to show the
individual entries. Currently the list is sorted in Descending order!
HINT: If you enable FRAME
OBJECT and OBJECT INFORMATION as shown above when you go down the list each
entry highlighted will be centered and framed with the information dialog
show. Very handy!
To label the clusters on the
sky display use View | Display Explorer and EXPAND the Abell Galaxy Clusters
group and check the fieild(s) you want to label.
View | Display Explorer
Place check next to field(s)
The image below shows the
NGC/IC objects and Abell Galaxy Clusters labeled.
Because the data uses EPOCH
1950 it needs to be compiled using 1950 instead of the default EPOCH 2000.
See above showing this.
Data | Import to compile
Data compiled using
EPOCH 1950
From the
Abell HDR file with the field definition the following is my choice of
fields for the data. If you do not like the fields I have chosen the data
can be compiled quite easily with the
fields you like instead <-------Click here!
;Copyright Software Bisque 2007
>SEARCH 1,5
>RAHOURS 9,10
>RAMINUTES 11,15
>DECSIGN 17,17
>DECDEGREES 18,19
>DECMINUTES 21,22
>IDENTIFIER Abell Galaxy Clusters
>PARSE "Abell Cluster number" 1,5
>PARSE "In Abell Sample 1-Yes 2-No" 7,7
>PARSE "Mag 10 brghtest clstr member" 24,28
>PARSE "Distance to group" 31,31
>PARSE "Richness Group" 34,34
>PARSE "Galactic Long / Lat" 36,49
>PARSE "Area computed from Clus_Rad" 98,103
>PARSE "x y z Component Distance" 118,130
>LOADMEMORY
>OBJECT TYPE 10
>CATALOG CLASS=OBJECTS
Object Type 10 above is "Clusters
of Galaxies". Make sure this object type has been enabled or they will now show!
Or recompile the dataset as another object type which is ENABLED.
View | Display Explorer
And check next to Cluster of Galaxies
HINT:
Typing in Cluster of Galaxies in the Go To:
field in the Display Explorer takes you directly to the object type,
quickly!
The ">IDENTIFIER Abell Galaxy
Clusters" above is what defines the
how the data is searched.
If you don't like the long name you can just re-compile the data with a new
Identifier. You don't have to edit the header just RECOMPILE it. Best to
also make the change stick by altering the header too.
Example, change the identifier
to "AGC's" Abell Galaxy Clusters
then just press Compile. See below.
New Identifier
Change and Compile
Now use Edit | Find AGC's
{number to search} or EXPAND the entry named AGC's under Edit | Find | Sky
Database (SDB's).
WARNING!
The Symbol used for Clusters
of Galaxies is quite faint! It can be VERY difficult to see. You can
label the galaxy clusters for easy
identification, RECOMPILE the text using a different object type (i.e.
REFERENCE POINTS), or even make your own unique symbol by
creating a new custom Object Type.
NOTE!
Unlike most other symbols the Cluster
of Galaxies symbol cannot be edited. However, you can change the color if
you like but even then the symbol is quite small and again difficult to see.
XTENSION= 'TABLE ' / Table extension
BITPIX = 8 / Character data
NAXIS = 2 / Simple 2-D matrix
NAXIS1 = 130 / Number of characters per row
NAXIS2 = 2712 / Number of rows in the table
PCOUNT = 0 / No "random" parameters
GCOUNT = 1 / Only one group
TFIELDS = 24 / Number of fields per row
EXTNAME = 'ABZWClus_Abell' / Abell & Zwicky Clus. of Gal., Abell Clusters
AUTHOR = 'Abell, G. O.; Zwicky, F., et al.'
REFERENC= '1958, ApJS, 3, 211; 1961-68, Caltech'
DATE = '01/08/91' / Date FITS table verified (dd/mm/yy)
TTYPE1 = 'Abell ' / Abell cluster number
TBCOL1 = 2 / Start column
TFORM1 = 'I4 ' / Fortran format
TTYPE2 = 'Abell_Flag' / '2' if in Abell's statistical samp.; '1' if not
TBCOL2 = 7 / Start column
TFORM2 = 'I1 ' / Fortran format
TTYPE3 = 'RAH ' / Hours RA, 1950.0
TBCOL3 = 9 / Start column
TFORM3 = 'I2 ' / Fortran format
TUNIT3 = 'h ' / Units are hours
TTYPE4 = 'RAM ' / Minutes RA, 1950.0
TBCOL4 = 12 / Start column
TFORM4 = 'F4.1 ' / Fortran format
TUNIT4 = 'min ' / Units are minutes of time
TTYPE5 = 'DecSign ' / Sign Dec, 1950.0
TBCOL5 = 17 / Start column
TFORM5 = 'A1 ' / Fortran format
TTYPE6 = 'DecD ' / Degrees Dec, 1950.0
TBCOL6 = 18 / Start column
TFORM6 = 'I2 ' / Fortran format
TUNIT6 = 'deg ' / Units are degrees
TTYPE7 = 'DecM ' / Minutes Dec, 1950.0
TBCOL7 = 21 / Start column
TFORM7 = 'I2 ' / Fortran format
TUNIT7 = 'arcmin ' / Units are minutes of arc
TTYPE8 = 'Mag ' / Magnitude of 10th brightest cluster member
TBCOL8 = 25 / Start column
TFORM8 = 'F4.1 ' / Fortran format
TUNIT8 = 'mag ' / Units are magnitudes
TTYPE9 = 'Dist_Grp' / Distance group, see comment
TBCOL9 = 31 / Start column
TFORM9 = 'I1 ' / Fortran format
COMMENT Dist_Grp: Based on Mag; codes indicate a magnitude range as follows:
COMMENT Dist_Grp: '1'= 13.3 - 14.0; '2'= 14.1 - 14.8; '3'= 14.9 - 15.6;
COMMENT Dist_Grp: '4'= 15.7 - 16.4; '5'= 16.5 - 17.2; '6'= 17.3 - 18.0;
COMMENT Dist_Grp: '7'= > 18.0
TTYPE10 = 'Rich_Grp' / Richness group, see comment
TBCOL10 = 34 / Start column
TFORM10 = 'I1 ' / Fortran format
COMMENT Rich_Grp: Galaxy counts depend on codes as follows: '0'= 30 - 40;
COMMENT Rich_Grp: '1'= 50 - 79; '2'= 80 - 129; '3'= 130 - 199; '4'= 200 - 299;
COMMENT Rich_Grp: '5'= 300 or over.
TTYPE11 = 'GLon ' / Galactic longitude
TBCOL11 = 37 / Start column
TFORM11 = 'F6.2 ' / Fortran format
TUNIT11 = 'deg ' / Units are degrees
TTYPE12 = 'GLat ' / Galactic latitude
TBCOL12 = 44 / Start column
TFORM12 = 'F6.2 ' / Fortran format
TUNIT12 = 'deg ' / Units are degrees
TTYPE13 = 'Lamb_Dist' / Lambert distance (RL), see comment
TBCOL13 = 52 / Start column
TFORM13 = 'F7.4 ' / Fortran format
COMMENT Lamb_Dist: Lambert distance from the nearest galactic pole, defined by:
COMMENT Lamb_Dist: RL = 2 sin ((90-b)/2).
TTYPE14 = 'Lamb_X ' / X Lambert coord., XL = 2 sin l sin ((90-b)/2)
TBCOL14 = 60 / Start column
TFORM14 = 'F7.4 ' / Fortran format
TTYPE15 = 'Lamb_Y ' / Y Lambert coord., YL= 2 cos l sin ((90-b)/2)
TBCOL15 = 68 / Start column
TFORM15 = 'F7.4 ' / Fortran format
TTYPE16 = 'GLon_SGal' / Supergalactic longitude, de Vaucouleur's system
TBCOL16 = 77 / Start column
TFORM16 = 'F6.2 ' / Fortran format
TUNIT16 = 'deg ' / Units are degrees
TTYPE17 = 'GLat_SGal' / Supergalactic latitude, de Vaucouleur's system
TBCOL17 = 84 / Start column
TFORM17 = 'F6.2 ' / Fortran format
TUNIT17 = 'deg ' / Units are degrees
TTYPE18 = 'Clus_Rad' / Corrected Abell cluster radius
TBCOL18 = 92 / Start column
TFORM18 = 'F4.2 ' / Fortran format
TUNIT18 = 'deg ' / Units are degrees
TTYPE19 = 'Clus_Area' / Cluster area computed from Clus_Rad
TBCOL19 = 98 / Start column
TFORM19 = 'F6.3 ' / Fortran format
TUNIT19 = 'deg**2 ' / Units are square degrees
TTYPE20 = 'Pop ' / Mean apparent population (galaxies/deg**2)
TBCOL20 = 106 / Start column
TFORM20 = 'I4 ' / Fortran format
TTYPE21 = 'Dist ' / Radial distance to cluster, RH (H=100 km/s/Mpc)
TBCOL21 = 112 / Start column
TFORM21 = 'I3 ' / Fortran format
TUNIT21 = 'Mpc ' / Units are Megaparsecs
TTYPE22 = 'Dist_X ' / X component of Dist, XH = RH * cos b sin l
TBCOL22 = 117 / Start column
TFORM22 = 'I4 ' / Fortran format
TTYPE23 = 'Dist_Y ' / Y component of Dist, YH = RH * cos b cos l
TBCOL23 = 122 / Start column
TFORM23 = 'I4 ' / Fortran format
TTYPE24 = 'Dist_Z ' / Z component of Dist, ZH = RH * sin b
TBCOL24 = 127 / Start column
TFORM24 = 'I4 ' / Fortran format
END
Correct! Because this is a cluster of galaxies
there isn't any magnitude available. Note the field "Magnitude of 10th brightest cluster member".
This magnitude IS reported in the
object information dialog.
>PARSE "Mag 10 brghtest clstr member" 24,28
NOTE: The
field name of the field has been abbreviated because of space constraints! |
