Selecting Defining Sources for the Next ICRF Based on Source Structure

Abstract

The intrinsic radio structure of the extragalactic sources is one of the limiting errors in the definition of the International Celestial Reference Frame (ICRF). This paper reports about the ongoing work to monitor the structural evolution of the ICRF sources by using the Very Long Baseline Array and other VLBI telescopes around the world. Based on more than 5000 VLBI images produced from such observations, we have assessed the astrometric suitability of 80% of the ICRF sources. The number of VLBI images for a given source varies from 1 for the least-observed sources to more than 20 for the intensively-observed sources. From this analysis, we identify a subset of 194 sources that are highly compact at any of the available epochs. Such sources are prime candidates to define the next ICRF with the highest accuracy.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2007
Accession Number
ADA483467

Entities

People

  • A. Collioud
  • A. L. Fey
  • D. A. Boboltz
  • J. I. Camargo
  • P. Charlot
  • R. Ojha

Organizations

  • United States Naval Observatory

Tags

DTIC Thesaurus Topics

  • 5G Wireless Networks
  • Abstracts
  • Accuracy
  • Band Structures
  • Electronic Mail
  • Energy Bands
  • Frequency
  • Hemispheres
  • Indicators
  • Observation
  • Observatories
  • Personal Information Managers
  • Radio Frequency
  • Radio Telescopes
  • Southern Hemisphere
  • Telescopes
  • X Band

Fields of Study

  • Physics

Readers

  • Astronomy/Astrophysics
  • Systems Analysis and Design

Technology Areas

  • Space