This page provides links to the full 2QZ and 6QZ catalogues and a description of the catalogue table format. We also provide assorted extra data (such as the position of holes in the survey), as well as describing the format of the spectra data available.
The catalogue is a flat ASCII file containing the entries for each object on a separate line, so that the full 2QZ catalogue (NGP and SGP) contains 47768 lines with the 6QZ catalogue containing another 1657 lines in an identical format. A simple ASCII format was chosen for ease of use and flexibility. We should note that databases much larger than the current 2QZ/6QZ really require a more advanced database system to be easily accessible.
The full combined 2QZ and 6QZ data can be found in one catalogue:
There are also catalogue files available for the 2QZ SGP and NGP strips separately (useful for mask making etc). As well as a separate 6QZ catalogue file (SGP only):
The format of the data is described in the table below and also in the 2QZ catalogue paper (paper XII). The format entries below are based on the standard FORTRAN format descriptors. This catalogue format has been modified to contain more information that the original catalogue format of the 10k data release (Croom et al 2001). In particular, B1950 coordinates have been included as well as sector identifiers.
| Field descriptor | Format | Description |
| Name | a16 | IAU format object name, e.g.: J010946.1-274524 The 2QZ label is omitted. i.e. full name is: 2QZ J010946.1-274524 |
| RA(J2000) | i2 i2 f5.2 | Right ascension J2000 (hh mm ss.ss) |
| Dec(J2000) | a1i2 i2 f4.1 | Declination J2000 (+/-dd mm ss.s) |
| Catalogue number | i5 | Internal catalogue object number |
| Catalogue name | a10 | Internal catalogue object name (all references should be to the IAU format name). |
| Sector | a25 | Name of the sector this object inhabits |
| RA(B1950) | i2 i2 f5.2 | Right ascension B1950 (hh mm ss.ss) |
| Dec(B1950) | a1i2 i2 f4.1 | Declination B1950 (+/-dd mm ss.s) |
| UKST field | i3 | UKST survey field number |
| XAPM | f9.2 | APM scan X position (~8 micron pixels) |
| YAPM | f9.2 | APM scan Y position (~8 micron pixels) |
| RArad | f11.8 | Right ascension B1950 (radians) |
| Decrad | f11.8 | Declination B1950 (radians) |
| bj | f6.3 | bj magnitude |
| u-bj | f7.3 | u-bj colour |
| bj-r | f7.3 | bj-r colour [including r upper limits as (bj-rlim-10)] |
| Nobs | i1 | Number of observations made with 2dF |
| Observation #1 | ||
| z1 | f6.4 | Redshift |
| q1 | i2 | Identification quality x 10 + redshift quality |
| ID1 | a10 | Identification |
| date1 | a8 | Observation date |
| fld1 | i4 | 2dF field number x 10 + spectrograph number |
| fibre1 | i3 | 2dF fibre number (in spectrograph) |
| S/N1 | f6.2 | Signal-to-noise ratio in the 4000-5000A band |
| Observation #2 | ||
| z2 | f6.4 | Redshift |
| q2 | i2 | Identification quality x 10 + redshift quality |
| ID2 | a10 | Identification |
| date2 | a8 | Observation date |
| fld2 | i4 | 2dF field number x 10 + spectrograph number |
| fibre2 | i3 | 2dF fibre number (in spectrograph) |
| S/N2 | f6.2 | Signal-to-noise ratio in the 4000-5000A band |
| Additional data | ||
| zprev | f5.3 | Previously known redshift (Veron-Cetty & Veron 2000) |
| radio | f6.1 | NVSS radio flux (mJy) |
| X-ray | f7.4 | RASS x-ray flux, 0.2-2.4keV (x10-13 erg s-1 cm-2) |
| dust | f7.5 | EB-V (Schlegel, Finkbeiner & Davis 1998) |
| comments1 | a20 | Specific comments on observation 1 |
| comments2 | a20 | Specific comments on observation 2 |
There are 45 seperate entries for each object (counting hh mm ss as separate entries). Every entry contains data, but in some cases (for example the details of a second observation when none has occured) these may just be "-" (for strings) or "0.000" (for numerical values) if no actual data is avaliable. Note that the observations are strictly ordered on the basis of quality, and so the best ID for a particular object will always be ID1.
A number of objects were observed three or more times. The third, fourth...etc entries are not include in the main catalogue file, and in many cases are of low quality (as fields were re-observed if found to have low completeness). However, for completeness we also provide files containing all these repeat IDs (the best two IDs are always in the main catalogue file).
First there is a file containing all the repeats:
Second we have separate files for the 2QZ NGP and SGP strips and the 6QZ (SGP only):
The format of these files is as follows:
| Field descriptor | Format | Description |
| Name | a16 | IAU format object name, e.g.: J010946.1-274524 The 2QZ label is omitted. i.e. full name is: 2QZ J010946.1-274524 |
| RA(J2000) | i2 i2 f5.2 | Right ascension J2000 (hh mm ss.ss) |
| Dec(J2000) | a1i2 i2 f4.1 | Declination J2000 (+/-dd mm ss.s) |
| Catalogue name | a10 | Internal catalogue object name (all references should be to the IAU format name). |
| bj | f6.3 | bj magnitude |
| u-bj | f7.3 | u-bj colour |
| bj-r | f7.3 | bj-r colour [including r upper limits as (bj-rlim-10)] |
| z | f6.4 | Redshift |
| q | i2 | Identification quality x 10 + redshift quality |
| ID | a10 | Identification |
| date | a8 | Observation date |
| fld | i4 | 2dF field number x 10 + spectrograph number |
| fibre | i3 | 2dF fibre number (in spectrograph) |
| S/N | f6.2 | Signal-to-noise ratio in the 4000-5000A band |
| rep number | i1 | repear number of this observation (i.e. if 3, this is the third observation) |
| comments | a20 | Specific comments this observation |
A key component in the calculation of completeness, coverage, area etc. are the sectors files. These list all the independent regions consisting of areas made by the overlaps of 2dF pointings. These are called sectors. The lists of sectors are given in two files:
We do not provide a sectors file for the 6QZ.
They can use used in a number of ways, in particular to define completeness
masks in an optimal way using the make_mask.f
code.
Each sector is defined by a name, e.g.: S_169_170_247 where the "S" denotes
sgp and the numbers denote the fields which overlap to produce this sector,
in this case, 2dF fields 169, 170 and 247. The format of the sectors
file is as follows:
| sector_name | not_sector_name | area | n_ran | sector_RA_Decs | not_sector _RA_Decs |
Each of the entries are described below:
| name | description |
| sector_name | The name of the sector e.g.: S_169_170_247 |
| not_sector_name | A string defining nearby fields which do not overlap with the sector, e.g.: NOT_169_248 |
| area | area of sector in square degrees |
| n_ran | number of random points in Monte Carlo integration of sector area |
| Sector_RA_Decs | positions of the field centres in RA and Dec (B1950; radians) which make up the sector. |
| not_sector _RA_Decs | positions of the field centres in RA and Dec (B1950; radians) which are listed in the not_sector_name string. |
In order to construct accurate survey masks, a user will also require the survey boundaries (on a field by field basis) and the positions of holes. Because the input catalogue was derived in the B1950 system, all the limits and holes are also in the B1950 system.
The survey strips each consist of 15 UKST fields. The RA and dec limits (in B1950 coordinates) which provide the limits within each plate are contained in the files below (in radians):
NGP plate limits
SGP plate limits
The holes are specified by four corners in RA and dec. These are converted from the APM (x,y) coordinates in which the holes were originally derived. RA and dec are in radians:
We provide the coordinates of each of the 2dF and 6dF survey field centres. The coordinates were defined in the B1950 system for 2dF and J2000 for 6dF. The 2dF field centres were used in the construction of the sectors.
2dF field centres
6dF field centres
We provide the spectroscopic data for all the 2dF observations that constitute the 2QZ catalogue, as well as all the 6dF observations that are contained within the 6QZ catalogue. The small number of spectra taken from other sources are not contained within the spectral database, althought their IDs and redshifts remain in the catalogue.
Each spectrum is contained in an individual FITS file. The FITS file names are the names of the objects followed by "a.fits", "b.fits", "c.fits" ....etc. e.g.: J005955.9-315951a.fits (and infact, on the CD-ROM these are also gzipped by default). The a, b, c ... indicates whether the spectrum is associated with observation 1 (a), the adopted best spectrum, or observation 2, 3, 4 ...etc.(b, c, d ...etc) (when we have made more than one observation). They are found on the CD-ROM in the fits/ sub-directory, and are further sub-divided on the basis of RA, into directories at one hour intervals.
The spectra are not flux calibrated. We provide a simple Perl script to extract a given list of spectra from the CD called get_fits.pl . Given a file containing catalogue entries for your selected objects this script will copy the corresponding .fits.gz files to a specified location.
We provide two varieties of FITS file. Long and Short.
There are a number of extensions in each FITS file:
This version of the spectra contains only the primary image (i.e. Extension 0 discussed above). This is the version available on the CD (due to space restrictions), or if the short FITS option is selected on the WWW page. Note that bad pixels have their values set to -200 in the simple spectrum.
As part of the 2QZ spectra analysis carried out by Croom et al (2002) composite spectra were constructed. These are available for download.
We provide various observational details of the 2QZ 10k catalogue. The data are arranged by observing run (note: the name of each run is based on the date that 2dF was placed on the telescope, not the start date of a particular observation), and include exposure times, the number of 2dF fibres placed on QSO candidates and general comments on the conditions or any technical faults etc. A plain text version of this observing log is available here:
A small number of the observation where in particularly poor conditions and were not included in the final spectral database. These are indeicated by "NOT INC." in the comments column.