From Geoscience Australia
JSON format icon JSON RDF format icon RDF ISO19115-3 XML

Optical Spectra of Candidate Southern Hemisphere International Celestial Reference Frame (ICRF) flat-spectrum Radio Sources

Created 16/10/2025

Updated 16/10/2025

JSON format icon JSON RDF format icon RDF ISO19115-3 XML

Furthering our continuing program of spectroscopic observations we present redshifts for 126 radio quasars. Data were obtained with five large telescopes, the 3.58 m New Technology Telescope, the NTT, of the European Southern Observatory, the two 8.2 m Gemini telescopes, the 2.5 m Nordic Optical Telescope, the NOT, and the 6-meter Big Azimuthal Telescope, the BTA, of the Special Astrophysical Observatory in Russia. The targets were selected from the International VLBI Service (IVS) candidate International Celestial Reference Catalogue which forms part of an observational VLBI program to strengthen the celestial reference frame. We obtained spectra of the potential optical counterparts of more than 150 flat-spectra compact radio sources, and measured redshifts of 125 extragalactic objects, together with 22 BL Lac objects. These identifications will add significantly to the precise radio-optical frame-tie to be undertaken by GAIA, which is due to be launched in 2013. These results add significantly to the existing data regarding analysis of the distribution of source proper motions over the celestial sphere and serve for identification of the distant quasars in optical and radio wavelengths. Additionally, we observed five radio sources from the FIRST Catalogue that were selected on the basis of their colours, with the 2.5 m NOT telescope. Three quasars were found with $z>4$.

Files and APIs

Tags

Additional Info

Field Value
Title Optical Spectra of Candidate Southern Hemisphere International Celestial Reference Frame (ICRF) flat-spectrum Radio Sources
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/3cd0abcd-8a76-444c-a6e3-4215f78d9cab
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 22/04/2018
Geospatial Coverage Australia
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Optical Spectra of Candidate Southern Hemisphere International Celestial Reference Frame (ICRF) flat-spectrum Radio Sources". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/optical-spectra-of-candidate-southern-hemisphere-international-celestial-reference-frame-icrf-f