Telescopes

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12

baseline

Very Large Array (VLA),NM

27 25-meter telescopes

Slide 130

Radio interferometer

baseline

RYLE telescope

England

8 14-meter telescopes

Slide 131

Radio interferometer

baseline

Westerbork Synthesis Radio Telescope

(WSRT)

Netherlands

14 25-meter telescopes

Slide 132

VLBA Very Long Baseline Array

10 telescopes from Hawaii to St. Croix

Slide 133

Millimeter interferometer

baseline

Hat Creek Radio Observatory CA 10 elements, 6-meter telescopes

Slide 134

Millimeter interferometer

baseline

Owen’s Valley Radio Observatory (OVRO), CA 6 10.4-meter telescopes

Slide 135

Millimeter interferometer

baseline

Nobeyama Millimeter Array

(NMA)

Japan

6 10-meter telescopes

Slide 136

Submillimeter interferometer

baseline

CSO/JCMT Interferometer, Mauna Kea

First astronomical interferometer to operate at submillimeter frequencies

151.91m baseline, 1.1” resolution at 345GHz

Slide 137

Aperture synthesis

What is the longest baseline achieved?

.

Slide 138

Aperture synthesis

.

HALCA, Highly Advanced Laboratory for Communications and Astronomy.

In Japanese, HALCA means `far away’

8-meter radio telescope in elliptical earth orbit

21,000 km at apogee

Provides baselines 3 times longer

than earth-based observations

(earth’s radius = 6378 km)

1.6GHz, 5GHz, 22GHz

baseline

Slide 139

Aperture synthesis

.

Resolution = 2cm/24,000km

Resolution = 0.002”

baseline

HALCA

Slide 140

Space VLBI

Ground-based telescopes only

HALCA with 10 earth-based

telescopes

The strongest radio signals are produced near the center of a quasar where astronomers believe that hot gas and stars are interacting with a super-massive black hole.

The material which is being blown out from the quasar can be seen more clearly in the HALCA image.

Slide 141