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Resource Record Summary

Catalog Service:
2dF QSO Redshift (2QZ) Survey

Short name: TWODFQSOZ
IVOA Identifier: ivo://nasa.heasarc/twodfqsozPublisher: NASA/GSFC HEASARCivo://nasa.heasarc/ASD[Pub. ID]
More Info: https://heasarc.gsfc.nasa.gov/W3Browse/all/twodfqsoz.html
VO Compliance: Level 2: This is a VO-compliant resource.
Status: active
Registered: 2024 May 03 00:00:00Z
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Description


The final catalog of the 2dF QSO Redshift Survey (2QZ) is based on Anglo-Australian Telescope 2dF spectroscopic observations of 44,576 color-selected (u, b<sub>J</sub>, r) objects with 18.25 < b<sub>J</sub> < 20.85 selected from automated plate measurement scans of UK Schmidt Telescope (UKST) photographic plates. The 2QZ comprises 23,338 quasi-stellar objects (QSOs), 12,292 galactic stars (including 2,071 white dwarfs) and 4,558 compact narrow emission-line galaxies. The authors obtained a reliable spectroscopic identification for 86 per cent of objects observed with 2dF. They also report on the 6dF QSO Redshift Survey (6QZ), based on UKST 6dF observations of 1,564 brighter (16 < b<sub>J</sub> < 18.25) sources selected from the same photographic input catalog. In total, the authors identified 322 QSOs spectroscopically in the 6QZ. The completed 2QZ is, by more than a factor of 50, the largest homogeneous QSO catalog ever constructed at these faint limits (b<sub>J</sub> < 20.85) and high QSO surface densities (35 QSOs/deg<sup>2</sup>). As such, it represents an important resource in the study of the Universe at moderate-to-high redshifts. The survey area comprised 30 UKST fields, arranged in two 75 degrees by 5 degrees declination strips, one passing across the South Galactic Gap centered on Dec = -30 degrees (the SGP strip), and the other across the North Galactic Gap centered on Dec = 0 degrees (referred to in the reference paper as the equatorial strip, but also known as the NGP strip. The total survey area is 721.6 deg<sup>2</sup>, when allowance is made for regions of sky excised around bright stars. Spectroscopic observations of the input catalogue were made with the 2dF instrument at the Anglo-Australian Telescope (AAT; the 2QZ sample) and the 6dF instrument at the UKST (the 6QZ sample). 2dF spectroscopic observations began in January 1997 and were completed in April 2002. Six-degree Field observations were performed over the period 2001 March-2002 September. This online catalog was created by the HEASARC in October 2010 based on the machine-readable table 2qz.dat obtained from the CDS (their catalog VII/241). This is a service provided by NASA HEASARC .

More About this Resource

About the Resource Providers

This section describes who is responsible for this resource

Publisher: NASA/GSFC HEASARCivo://nasa.heasarc/ASD[Pub. ID]

Creator: Croom et al. Contributor:

Contact Information:
X NASA/GSFC HEASARC help desk
Email:

Status of This Resource

This section provides some status information: the resource version, availability, and relevant dates.

Version: n/a
Availability: This is an active resource.
  • This service apparently provides only public data
Relevant dates for this Resource:
  • Representative: 2024 May 03

This resource was registered on: 2024 May 03 00:00:00Z
This resource description was last updated on: 2024 May 03 00:00:00Z

What This Resource is About

This section describes what the resource is, what it contains, and how it might be relevant.

Resource Class: CatalogService
This resource is a service that provides access to catalog data. You can extract data from the catalog by issuing a query, and the matching data is returned as a table.
Resource type keywords:
  • Catalog
Subject keywords:
  • Survey Source
This service provides data from:
  • facility: GALAXY CATALOG
Intended audience or use:
  • Research: This resource provides information appropriate for supporting scientific research.
More Info: https://heasarc.gsfc.nasa.gov/W3Browse/all/twodfqsoz.html Literature Reference: 2004MNRAS.349.1397C

Related Resources:

Services that provide access to data in this resource:
HEASARC TAP ivo://nasa.heasarc/services/xamin [Res. ID]

Data Coverage Information

This section describes the data's coverage over the sky, frequency, and time.

Reference Coordinate System: UTC-ICRS-TOPOXXivo://STClib/CoordSys#UTC-ICRS-TOPO[Res. ID]

Sky Coverage: Regions covered:

  • All-sky: The data from this resource is distributed over the entire sky.
Typical Size Scale (Region of Regard): , 0.0166666666666667 deg

Wavebands covered:

  • Optical

Available Service Interfaces

Simple Cone SearchXXSearch Me

This is a standard IVOA service that takes as input a position in the sky and a radius and returns catalog records with positions within that radius.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for the standard interface:
  • https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=twodfqsoz&
Maximum search radius accepted: 180 degrees
Maximum number of matching records returned: 99999
This service supports the VERB input parameter:
Use VERB=1 to minimize the returned columns or VERB=3 to maximize.
Table Access Protocol - Auxiliary ServiceXX

This is a standard IVOA service that takes as input an ADQL or PQL query and returns tabular data.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for the standard interface:
  • https://heasarc.gsfc.nasa.gov/xamin/vo/tap
Custom Service

This is service that does not comply with any IVOA standard but instead provides access to special capabilities specific to this resource.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for this service interface:
  • URL-based interface: https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=twodfqsoz
Custom Service

This is service that does not comply with any IVOA standard but instead provides access to special capabilities specific to this resource.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for this service interface:


Developed with the support of the National Science Foundation
under Cooperative Agreement AST0122449 with the Johns Hopkins University
The NAVO project is a member of the International Virtual Observatory Alliance

This NAVO Application is hosted by the Space Telescope Science Institute

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