Short spacings (RUN UV_SHORT and RUN UV_ZERO)

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Short spacings (RUN UV_SHORT and RUN UV_ZERO)

Let's note the diameter of the single-dish antenna (m for the IRAM-30m telescope) used to produce the short-spacing information and the diameter of the interferometer antennas (m for PdBI). We already mentioned that a multiplicative interferometer filters out all the spatial frequencies smaller than meters. When this information is needed to get reliable results, the source should also be observed with a single-dish antenna to produce the missing information. The single-dish antenna furnishes information about all spatial frequencies up to meters (but this information is weighted by the single-dish beam shape, i.e. high frequencies are measured with a worse signal-to-noise ratio than low frequencies). To recover all the information at spatial frequencies smaller than meters, the diameter of single-dish antenna must be larger or equal to the diameter of the interferometer antennae: .

Subsections

- Algorithms to merge single-dish and interferometer information
  - Hybridization technique
  - Pseudo-visibility technique
    - General description
    - An important subset: The zero spacing
    - Single-dish vs interferometer weight
  - Comparison
- Practical considerations
  - When are short-spacing information needed?
  - How to optimize single-dish observations?
  - How to use your single-dish observations?