Projeto Observacional para 2007B - SO2007B-001

Autor: Julio Ignacio Bueno de Camargo
Instituição: OV/UFRJ
e-mail: camargo@ov.ufrj.br

Co-autores:
Marcelo Assafin
Alexandre H. Andrei
Dario Nepomuceno da Silva Neto
Roberto Vieira Martins

Título: Accessing the Limits of Coincidence Between Radio and Optical Centroids for ICRF Extragalactic Radio Sources

Resumo: The coincidence of the centers of emission of selected quasars at the optical and radio wavelengths has been the underlying assumption for the current reference frame adopted by the IAU, the International Celestial Reference Frame - ICRF, and its optical representation. Recent works report accurate optical positions of ICRF quasars which now challenge such scenario. We propose to carry out observations aiming at the detection of optical and radio positional differences from a sample of ICRF quasars with extended radio structure, to investigate this question more extensively and derive results of interest to astrophysics and reference frame studies. The current definition of the IAU celestial frame shall be brought back to visible wavelengths within the next decade, from observations of thousands of quasars with unprecedented positional precision at optical wavelengths as determined by the GAIA space mission. The results of this project are thus of interest to GAIA and to other planned space mission