Very long baseline interferometric observations made with an orbiting radio telescope

Area of Science:

• Astronomy and Astrophysics
• Radio Astronomy
• Space Science

Background:

• Interferometric observations are crucial for studying cosmic radio sources with high resolution.
• Previous limitations in baseline length have hindered detailed observations of distant celestial objects.

Purpose of the Study:

• To demonstrate the feasibility of space-ground interferometry for cosmic radio source observation.
• To test techniques for a dedicated space-based very long baseline interferometry (VLBI) observatory.

Main Methods:

• Utilized the Tracking and Data Relay Satellite System (TDRSS) as an orbiting observatory.
• Combined TDRSS data with observations from two 64-meter ground radio telescopes in Australia and Japan.
• Conducted observations at 2.3 GHz, achieving a maximum projected baseline of 1.4 Earth diameters.

Main Results:

• Successfully detected fringes for all observed quasars (1730-130, 1510-089, 1741-038).
• Achieved a significant projected baseline, enabling high-resolution observations.
• Validated the use of TDRSS in a space-ground interferometry configuration.

Conclusions:

• The experiment successfully demonstrated the capability of space-ground interferometry for radio astronomy.
• The techniques employed are suitable for future dedicated space VLBI missions.
• This approach significantly enhances the potential for detailed study of cosmic radio sources.