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Prerequisites far
New Research Initiatives
In order to be effective, the recommended new research initiatives
for the coming decade must be supported by a set of Prerequisites;
these are essential for the success of all the major programs but are
inexpensive by comparison. Although significant support already
exists for each, the Committee strongly recommends substantial aug-
mentations in the following areas, in which the order of listing carries
no implication of priority:
A. Instrumentation and detectors,
B. Theory and data analysis,
C. Computational facilities,
D. Laboratory astrophysics, and
E. Technical support at ground-based observatories.
The present chapter discusses the importance of these support ac-
tivities to the major research directions of the 1980's.
A. INSTRUMENTATION AND DETECTORS
The Astronomy Survey Committee recommends significantly ex-
panded support for instrumentation and detectors during the
coming decade as the most cost-effective way to increase the ca-
pabilities of both new and existing telescopes.
The past decade has seen spectacular advances in detector and
123
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124
ASTRONOMY AND ASTROPHYSICS FOR THE 1980's
instrumentation technology, resulting in two-dimensional array
detectors for optical, ultraviolet, and x-ray wavelengths, and large
gains in sensitivity in virtually all wavelength regions. Further
development of this technology on all fronts is imperative for the
efficient utilization of both ground-based telescopes and space
facilities. Improvements in ancillary instrumentation, such as
spectrometers, interferometers, and radio-frequency local oscilla-
tors, will also be important. As in the past, support for all of
these activities should come from a broad base, including the
National Sciences Foundation (NSF) grants program, the National
Aeronautics and Space Administration's (NASA'S) Research and
Analysis program, and funding provided through the National
Astronomy Centers. The potential gains are enormous, and the
cost is small compared with that of major new facilities.
A major detector-development program also exists in the mili-
tary community, especially for infrared detectors. Rapid declassi-
fication of the results of military research and development in this
area would be of immense value to astronomy. An efficient
means of transferring such declassified technology to the astro-
nomical community is urgently needed.
In many instances a technological breakthrough is only the first
step-one must next ensure an adequate supply of new compo-
nents to the astronomical community at reasonable cost. Com-
mercially available devices may not be well suited to astronomi-
cal needs, which usually include maximum sensitivity together
with the lowest possible background noise. Often, however,
commercial devices can be modified effectively and inexpen-
sively. University laboratories and private industry can contrib-
ute to these developments, and such initiatives should be en-
couraged.
The most critical needs for new detectors and instrumentation
during the 1980's are highlighted below; a more complete dis-
cussion of these and other projects can be found in the Panel
Reports, to be published as a Volume 2 of this survey.
1. Infrared array detectors. Infrared imaging and spectroscopy
from the ground and from space would be enormously ad-
vanced by the introduction of array detectors in the 1-30-~m
range, which are now being developed for military purposes but
which have not yet become astronomical tools. They should be
reviewed for timely declassification and adaptation to infrared
v
astronomy.
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Prerequisites for New Research Initiatives
125
2. Charge-coupled device (CCD) array detectors for the optical,
ultraviolet (uv), and x-ray regions. With nearly 100 percent
quantum efficiency, high geometric stability, and relatively low
readout noise, CCD arrays can be nearly perfect detectors in the
optical region; for optical-astronomy applications, however, the
devices should have larger area, larger pixels, lower noise, im-
proved blue response, and greater adaptability for large, close-
packed mosaics than at present. The wavelength coverage of such
detectors can be extended to the w region by the application of
high-efficiency phosphor coatings, although this should be tested
further.
Two-dimensional solid-state array detectors are of special value
in x-ray observations, since the amount of charge created in the
detector is a measure of the energy of each incident photon, so
that imaging and low-resolution spectroscopy can be carried out
simultaneously. Further development should pursue the goal of
detecting each individual photon with an energy resolution ap-
proaching the theoretical limit.
3. Millimeter- and submillimeter-wavelength radio receivers. At
high radio frequencies (including those sometimes considered to
lie in the far-infrared region), the greatest need is for more sen-
sitive coherent detectors. Cryogenic metal-semiconductor junc-
tions (Schottky barriers), InSb mixers, and superconducting junc-
tions will all require further development and increased funding
during the 1980's.
4. Gamma-ray detectors. Particular needs include greatly in-
creased flux sensitivity over the entire range, better energy reso-
lution for emission-line spectroscopy, and higher angular resolu-
tion to correlate gamma-ray sources more precisely with sources
observed at other wavelengths.
5. Cosmic-ray detectors. High sensitivity and resolution are
needed to investigate elemental and isotopic compositions
throughout the entire periodic table, particularly for heavy ele-
ments, whose abundances are extremely low. Devices of very
large area are needed to measure the low fluxes expected at
energies in the tera-election-volt range.
6. Optical and ultraviolet instrumentation. Greatly increased
efficiency in multiobject optical spectroscopy of faint objects can
be achieved using multichannel spectrometers. Increased atten-
tion should also be given to the use and development of highly
reflective optical coatings at all wavelengths, notably in the far w
region.
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26
ASTRONOMY AND ASTROPHYSICS FOR THE 1980's
B. THEORY AND DATA ANALYSIS
The Astronomy Survey Committee recommends support for an
expanded program of theoretical astrophysics and data analysis
during the coming decade in response to the rich accumulation
of data expected from both ground-based and spacecraft obser-
vatories.
Astronomy is a field in which new observational discoveries are
often unanticipated; their interpretation and eventual under-
standing require the incorporation of an ever-increasing range of
physical processes and concepts into astronomy. Theoretical
modeling, usually with the aid of modern computers, is neces-
sary to extrapolate the results of laboratory experiments into to-
tally unfamiliar astrophysical environments. Without extensive and
imaginative theoretical analysis, the observational data by them-
selves are often without apparent pattern or meaning. Further-
more, the new facilities to be put into operation during the 1980's
promise to produce data of unparalleled richness and complex-
ity, necessitating ever more sophisticated theoretical interpreta-
tion. The Survey Committee thus shares the view of the Panel on
Theoretical and Laboratory Astrophysics that the use of these new
facilities will stimulate a correspondingly increased level of theo-
retical activity. Funding agencies should therefore prepare to re-
spond to an increased demand for the support of theoretical as-
trophysics.
Theoretical astronomical research of the broadest scope has been
supported primarily by the NSF Astronomy Division. Such sup-
port is critical to astronomy and should be increased. A level of
funding 50 percent creaser than the present level, as a fraction
0 1 C} 1
Of NSF astronomy support, is a desirable goal. implementation
could be strengthened by the establishment of a program direc-
tor for theoretical astrophysics, as recommended by the Panel.
It is inappropriate that the NSF Astronomy Division bear the
burden of supporting the basic theory needed for a balanced
program in space astronomy. We recommend that NASA estab-
lish a strong, broad program in theoretical astrophysics compa-
rable in scope with the NSF program, as NASA has already done
in the area of theoretical solar-terrestrial physics.
It is important that this support include a grants program for
theory designed to further NASA'S overall mission for space-sci-
ence research but that is funded independently of specific in-
strumental programs. Such a grants program is necessary to en
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Prerequisites for New Research Initiatives
127
courage theoretical studies that relate results of different space-
science missions to each other and to the results of ground-based
astronomy, as well as to incorporate them fully into the concep-
tual framework of astronomy and physics. At the same time,
however, NASA should adequately support the analysis and
interpretation of data obtained from specific missions; since this
activity naturally includes theoretical interpretation, a significant
fraction of NASA support for theory should continue to be funded
through channels identified with specific instrumental programs.
The Committee believes that the effectiveness of the National
Astronomy Centers would be enhanced by the presence of strong
in-house theoretical groups. These groups should support the
activities of the Center user communities and should have a
number of permanent staff theorists above the critical minimum,
as do the Department of Energy national laboratories for re-
search in high-energy physics; it is particularly important that the
newly established Space Telescope Science Institute have a strong
in-house theoretical staff. Such theoretical groups should be built
up carefully in order to ensure appointments of the highest
quality.
C. COMPUTATIONAL FACILITIES
The Astronomy Survey Committee recommends that the acquisi-
tion of minicomputer and enhanced-minicomputer systems by the
U.S. astronomical community be substantially accelerated. About
30 such systems, to be replaced by more advanced systems at
intervals of approximately 6 years, are required for data reduc-
tion, image processing, and theoretical calculations during the
coming decade. However, as some forefront theoretical problems
will still require the largest and fastest computers available, the
Committee also recommends that federal agencies take steps to
provide continued access of the U.S. astronomical community to
such machines.
The increasing use of digital imagery in astronomy is already
producing a flood of valuable data requiring the extensive use of
computers for reduction and analysis. By about 1985, most ma-
jor telescopes will be equipped with CCD array detectors, the Very
Large Array will be in full operation in both continuum and
spectral-line modes, Space Telescope will be launched to carry out
a rich observational program in optical and uv astronomy, and
there will be increased use of microdensitometers to generate
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128
ASTRONOMY AND ASTROPHYSICS FOR THE 1980's
digital images from photographic plates. All together, as many as
a million images may be generated each year. If the scientific
content of these images is to be extracted efficiently, it is im-
perative that astronomers improve their capabilities for image re-
duction and analysis. Advances in computer technology now
make it possible to exploit the scientific opportunities afforded by
new imaging technologies at modest cost.
We stress that image processing is only part of the total pic-
ture: the inherent complexity of astrophysical phenomena to-
gether with the greatly improved ability to measure these phe-
nomena require increasingly sophisticated analytical techniques for
the interpretation of observations. Astronomical phenomena typi-
cally involve an intricate interplay of several strongly nonlinear
effects. In such situations, theoretical modeling by digital com-
putation often provides the only practical approach to under-
standing. The demand for computational facilities for theoretical
modeling will increase in parallel with the demand for ima~e
processing facilities in the 198()'s. liere again, advances in com-
puter technology allow the important scientific opportunities for
detailed theoretical modeling to be exploited at a modest cost.
Computational capability will continue to be provided through
three main sources: university computer centers, large com-
puters operated by national laboratories and observatories, and
dedicated minicomputers and superminicomputers. Computers at
national laboratories and observatories constitute a unique and
vital resource for handling some theoretical problems, and their
shared use by astronomers should be encouraged and ex-
panded. In recent years, however, new computer technology has
brought about a dramatic shift in the capability and cost-effec-
tiveness of minicomputers in comparison with the large central
computers operated by university computer centers. Minicompu-
ters and superminicomputers are now able to handle almost all
image processing, as well as many theoretical calculations. Their
cost-effectiveness compares favorably with that of the computers
operated by national laboratories and observatories and often
exceeds by a large margin that of many university computer
centers. Furthermore, they provide the flexibility and interactive
capability necessary for creative interpretation of observational data
and theoretical results. (These new computational opportunities
have been recognized not only in the United States but also
abroad; in 1979, for example, the United Kingdom's Science and
Engineering Research Council established a network of six linked
OCR for page 129
Prerequisites for New Research Initiatives
129
minicomputers to meet the image-processing requirements of U.K.
astronomers during the 1980's.) In order for these facilities to
operate effectively, attention and support must also be given to
the standardization and sharing of software for the most com-
monly encountered calculations.
The Committee believes that the acquisition by the U.S. astro-
nomical community of dedicated minicomputer- and supermini-
computer-based computational systems should be substantially
accelerated. However, the Committee also recognizes the exis-
tence of computational problems of outstanding importance to
astrophysics that can be attacked only with the most powerful
computers. We urge NSF and NASA to help ensure that qualified
astrophysicists continue to have access to the largest and most
sophisticated computing equipment available.
D. LABORATORY ASTROPHYSICS
The Astronomy Survey Committee recommends expanded sup-
port for the laboratory measurements of atomic, molecular, and
nuclear properties needed for the interpretation of nearly all as-
tronomical observations. Federal agencies should furthermore co-
ordinate their efforts in providing such support and should take
explicit account of the need for laboratory astrophysical data in
the planning of future scientific activities and missions.
The accuracy with which physical conditions can be inferred
from spectroscopic observations depends directly on the breadth
and precision of the data available for atomic, molecular, and
nuclear processes. The laboratory research that yields these data
has not been funded adequately during the past decade, with
increasingly damaging consequences for astronomical investiga-
tions. For example, uncertainties in solar opacities have hin-
dered precise predictions of solar neutrino emission, thereby
throwing doubt on an important scientific test of our under-
standing of stellar structure and evolution; lack of accurate mo-
lecular data is an obstacle to the quantitative understanding of
physical and chemical processes in interstellar clouds and pre-
vents confident use of remotely sensed spectra for an under-
standing of planetary atmospheres.
The funding of laboratory astrophysics has suffered from an
erratic pattern of support for atomic and molecular physics gen-
erally. This trend has resulted in a severe decline in the num-
ber of atomic and molecular physicists responding to the grow
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130
ASTRONOMY AND ASTROPHYSICS FOR THE 1980's
ing needs of astronomy. A strong stimulus is needed to attract
a greater fraction of existing laboratory talent to problems re-
lated to astronomy.
The 1980's will see the deployment of powerful new instru-
ments for astronomical spectroscopy and a resulting unprece-
dented growth in the quality and variety of astronomical spec-
troscopic data. An allied growth in laboratory astrophysics will be
required to utilize these new data fully. Expanded support by NSF
will be needed in the years ahead. We also recommend that NASA
make an increased effort in its mission-planning and Research and
Analysis programs to fund the laboratory measurements in basic
physics and chemistry that are needed for the interpretation of
astronomical observations from space. Of particular importance to
NASA missions are studies of highly ionized atoms relevant to w
and x-ray spectroscopy, of molecular physics relevant to infrared
and radio spectroscopy, and of heavy-nuclei interaction cross
sections relevant to cosmic-ray isotope and element spectros-
copy.
The Committee believes that NSF, NASA, and the Depa.l~ent of
Energy should develop coordinated programs for the support of
research in atomic, molecular, and nuclear physics, which are of
interest to astronomy and to other branches of science, and
should also support interdisciplinary workshops and symposia. We
furthermore urge NSF to increase its efforts to encourage labora-
tory astrophysics by coordinating the relevant activities in the
Astronomy and Physics Divisions.
Finally, we urge the National Bureau of Standards (NBS) to in-
crease its support of basic studies in atomic and molecular physics
and of laboratory astrophysics. These NBS programs have con-
tributed importantly to many fields of pure and applied physics
as well as to astronomy, and they provide an environment in
which vital cross-fertilization among these fields can occur.
E. TECHNICAL SUPPORT AT GROUND-BASED OBSERVATORIES
The Astronomy Survey Committee recommends expanded sup-
port for the technical personnel needed to ensure the develop
meet, maintenance, and enhancement of modern astronomical
instrumentation at ground-based observatories.
The efficient progress of optical, infrared, and radio astron-
omy in the coming decade is dependent on improvements in the
instrumental capability and continued productivity of ground-based
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Prerequisites for New Research Initiatives
observatories. Recent advances in instrumental techniques and
control systems, together with those foreseeable in the near fu-
ture, represent a potential for greatly increasing the capability of
both large and moderate-sized telescopes. These advances, how-
ever, are worthless to astronomy unless observatories have the
means to develop, implement, and maintain the working instru-
ments that take advantage of them.
The present shortage of technical personnel who are able to
assist in the development of instrumentation, as well as in its
maintainance and improvement, is a major difficulty. We urge
that funds be allocated to support such personnel, with the strong
proviso that the award of such funds should proceed through the
normal peer-review channels and that the basis of the award be
the excellence of the science proposed with the instrumentation
in question.
Small institutions and small telescopes should not be excluded
from such awards but should be supported if the scientific pro-
posals have merit. The modernization of small instruments at
reasonably good sites can help alleviate the pressure on large
telescopes in an extremely cost-effective way, and it provides a
unique resource for small-scale but highly innovative research.
131
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The Multiple-Mirror Telescope of the Smithsonian Institution and the
University of Arizona. (Photo courtesy of G. McLaughlin, Lunar and
Planetary Laboratory)
Representative terms from entire chapter:
survey committee
