leda Compilation of diameters site

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Search an object in the catalogue of diameters

This catalogue (table a106 in the database) presents the compilation of apparent diameters of galaxies. They are collected from the litterature and from surveys and are not corrected for Galactic extinction or for any other effect.

These raw diameters are used to derive

They are also used for evaluating the mean surface brightnesses and corrections in the computation of some other mean parameters. See also the article on size of galaxies from the NED knowledge database (Level 5).

In March 2006, the table counted 3.1 million measurements for 1.2 million galaxies.

Statistics on the catalogue

Description of the fields

Field: lax

Major Axis: decimal log of major axis log D (D in 0.1 arcmin) with uncertainty and quality flag in parentheses

(For instance, if the major axis logD=1, it means that D=10 in 0.1', i.e. D=1').

Field: sax

Minor Axis: decimal log of minor axis logd (d in 0.1 arcmin)

Field: isophote

Isophote: isophotal level in mag.arsec-2 for isophotal diameters

Field: dcode

Diameter Code: code for the type of diameter following "dcode" table:

Field: bandname

Photometric Band. The definitions are given in the "band_codes" table:

Field: quality

The quality flag has the following meaning:
description of quality flag
0regular measurement
1uncertain measurement, its weight is decreased by a factor 2 when computing the average value
3preliminary measurement, probably superseeded in a more recent publication, it is ignored unless no other measurement is available
4compilation, it is ignored unless no other measurement is available
9rejected measurement

HyperLeda Questions: leda@univ-lyon1.fr