Radio data

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Дата индексирования: Tue Oct 2 02:23:41 2012
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Radio data

Radio data are displayed in the following format:

After the title with name of cluster under examination and with line about kind of data under one, e.g.

Abell 0690

Radio data [optical data] [ radio source identifications] [radio spectra (1.0 or 1.1)]

several data sections follow. Every section contains well-formatted records of numerical and symbolic information and free-format comments after a '#' symbol. The comment may contain explanations, hints to inaccuracies or other information connected with the basic data.

Warning!
For most Abell clusters there is no optically identified cluster radio source. The corresponding parameter fields will be blank in these cases. Many data are also being folded into the database. However, the section 'Data' (below) can contain the information about radio measurements.
The authors will be grateful for any corrections and new cluster data for this service.

The first line contains the number of radio sources associated with the cluster (these are just those sources with entries in sections 'Radio galaxy', 'Radio source' and 'Radio spectrum' below). For example,

Radio sources in cluster: 2 #

Next line (if one presents)
Cluster image with APM-galaxies, NVSS radio sources and FIRST radio sources (TCL-applet 85 Kb)
contains the link on the TCL-applet for the work with graphical image of cluster field.

For clusters north of declination -40 degrees try the NRAO VLA Sky Survey (NVSS) browser. Get the list of NVSS radio sources within 3 Mpc from the cluster center by clicking on this link:

Radio sources from NRAO VLA Sky Survey in 3 Mpc radius circle

[Note that NVSS is still in progress and currently covers only part of the survey area have been mapped. Note also that for very nearby clusters the source list may be rather large.]

The next sections

COM (Comments) - can give a description of the situation with radio sources in cluster.

RGn radio galaxy - optical coordinates of identified radio galaxy - in order: epoch (B1950 or J2000), right ascension (hours, minutes, seconds), declination (degrees, arc-minutes, arc-seconds), reference for the coordinates. After '#' you may find the name of the radio galaxy.

RG1 radio galaxy: B1950 08 36 13.571 +29 01 14.76 VCC_95 #

You may extract the Radio-optical image centred on the corresponding radio galaxy if one presents in our database.

Below follow some parameters of the radio galaxy:
redshift z, measured optical magnitude (mV, mR, mB_J, etc., where V, R, B_J are corresponding filters), type - the optic type of galaxy, - with corresponding references for these data.

z 0.0788 OOE90 #
type cD GCP93 #
mV 14.26+-0.06 GCP93 #

The subsection 'Radio source' contains the radio coordinates of the source identified with the radio galaxy. We prefer to select the position of compact core components of radio sources or the most accurate ones. Because the coordinates of extended cluster radio sources are often displaced from the radio galaxy position, or are inaccurate, the radio position fields will be blank occasionally.

Radio source: J2000 08 39 15.827 +28 50 38.86 VCC_95 #

The subsection 'Radio spectrum' contains the following data:

observing frequency (in MHz);
measured flux density (in mJy or in Jy if there is '[Jy]' after '#' in line 'Radio spectrum'). We tried to reduce the data to BGPW77 flux density scale where possible.
corresponding flux density error;
reference for radio measurement and, following a '#', comments if any.


Radio spectrum: #
  FREQ. FLUX  ERR.  REF.  # Comments
   408  1.50   --   HLVW80 # B2
   ....................
  4850  0.399  --   BWE91 #

For few radio sources the big part of spectrum points was took from one of special papers (for example, EGRS, G91, LP80), then in line 'Radio spectrum' here is pointed out this reference.

The section 'Supplementary data' contains additional information on upper flux limits of cluster radio sources, on inaccurate or confused data, radio maps and so on. Below the 'Supplementary data' line are columns 'FREQ.', 'REF.' and 'Comments' that include the frequency of measurements, references and some comments about the respective radio measurements.

Supplementary data #
 FREQ. REF. # Comments
 1452  OOE90 # cD - WAT 6'12" VLA-maps at 1452.4 MHz with 1" resolution
 .....................

The last section 'Data' contains extracts of different DATA from publications in the format:
REF: DATA # comments. Data # O75: 08 36 12.2 +29 01 41 S2695= 0.51+-0.05 # 4' in p.a. 10 ........................................................
The line of abbreviations of parameters is often after REF: #. The first column frequently contains the name or number of the radio source of the corresponding catalog or the projected distance of the radio source from cluster center, in units of the Abell radius Ra = 3 Mpc (H0 = 50 km/sec/Mpc). The records for different sources from the same catalog are generally sorted by the latter parameter.
For faster access to the basic data this section will possibly be replaced by separate hyper-link later.

Alexander Gubanov, Heinz Andernach

01 March 1999