Project Cyclops, A Design... - Department of Earth and Planetary ...

Only a few such galaxies have been studied at this
wavelength because existing telescopes lack the necessary
sensitivity and resolution. Cyclops, however, would
permit detailed analyses of the hydrogen distribution in
galaxies, and perhaps in intergalactic space, out to
distances of cosmological significance. The data processing
system proposed for Cyclops would permit high
resolution (1 Hz) spectroscopy over a 100 MHz band on
a real-time basis, greatly speeding data acquisition and
ensuring the discovery of weak lines. Similarly, the
distribution of hydroxyl, and some of the more complex
interstellar molecules in other galaxies could be determined
out to cosmological distances. It is difficult to
assess the impact on astronomy of this wealth of new
data, but it would surely revolutionize astronomical
thinking.
In the past the detection of interstellar ions, atoms,
and molecules by radio techniques has been the result
primarily of a process that began with theoretical
estimates based on laboratory data. There have been a
few accidental discoveries, but usually the radio astronomer
has been provided with a careful estimate of just
what narrow frequency range to search. This nearly
complete reliance on prediction is due to the absence of
truly broadband, high spectral resolving power equipment.
As a result, many observable emission lines have
probably gone undetected because of either a lack of
understanding or imagination, or a lack of sufficiently
precise laboratory data. It is often difficult or impossible
to substitute laboratory procedures for the conditions
existing in interstellar space. Because of its powerful
spectral sensitivity, and remembering the parallel optical
situations, Cyclops should be able to complement the
predictive procedure by first observing the interstellar
absorption and emission lines. There seems little reason
to doubt the scientific value of employing such balanced
procedures.
Pulsars
It seems well established that pulsars are neutron stars
remaining after supernova explosions. Of the few dozen
known in our Galaxy, most were discovered by their
pulsed emissions, which are visible on telescope records
above the receiver and sky background noise. The rate of
discovery of pulsars has slowed almost to zero. Searching
for weak, unknown pulsars without prior knowledge of
their pulse periods is an excessively tedious process. It is
necessary to perform an autocorrelation analysis or
spectrum analysis of a long sample of signals over the
possible range of pulse periods (or pulse repetition
frequencies), for each point in the sky and each radio
frequency band to be examined. An extremely sensitive
antenna such as Cyclops, with the capability of multiple
beams and sophisticated spectral analysis, would advance
the search for pulsars dramatically. It has been estimated
that there are 104 to l0 s pulsars in our Galaxy and
Cyclops could probably detect most if not all of them.
Pulsars undoubtedly exist in other galaxies but none
has so far been detected. Studies of galactic and stellar
evolution would benefit greatly if these extragalactic
pulsars could be observed. Cyclops could detect most of
the pulsars in the Virgo cluster of galaxies, for example,
at a distance of 14 megaparsecs, assuming they have the
characteristics of the well-known Crab pulsar.
Stars
In radio astronomy, only a few individual normal
stars besides the Sun have been observed so far, and then
just barely, Cyclops, because of its sensitivity, should be
able to observe many of the nearer stars and add
enormously to our knowledge of the physics of stellar
coronas as a function of stellar type. Present knowledge
is crude, relying as it does almost solely on extrapolation
of solar data. Further, with the addition of suitable
very long base-line interferometric (VLBI) capability, it
should be possible to determine stellar diameters on the
order of 10-3 arc-second or better. Furthermore, if a
satisfactory background reference source exists in the
field of view of the array element, it should be possible
to study stellar motion and planetary perturbations to
equal or better precision. Besides the fundamental
astronomical interest in such observations, the planetary
data would be of particular use in sharpening the
Cyclops search strategy. At present, we have only crude
estimates of the probability of occurrence of planets in
the life zone of stars.
Equipment
There is another way in which radio astronomy could
benefit from the prosecution of the Cyclops plan argued
here, and that is in the matter of technological improvements.
Radio astronomers have been prominent in the
development of antenna and electronic circuit techniques,
as well as in the art of data analysis. By and
large, however, their efforts have been severely limited
by insufficient engineering funds. Straightforward developments
of the state of the art usually have had to wait
upon the somewhat haphazard and occasional support
provided by other space, military, or industrial projects.
But, in principle, Cyclops requires the efficient and
economic production of, and development of, just the
type of equipment every radio observatory has or would
very much like to have. (There are other fields where
this is also true.) Therefore, a major spinoff of Cyclops
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