Gart Westerhout

Gart Westerhout (15 June 1927 – 14 October 2012) was a Dutch-American astronomer.^[1] Well before completing his university studies at Leiden, he had already become well-established internationally as a radio astronomer in the Netherlands, specializing in studies of radio sources and the Milky Way Galaxy based on observations of radio continuum emissions and 21-cm spectral line radiation that originates in interstellar hydrogen. He emigrated to the United States, became a naturalized citizen, and held a number of important scientific and management positions in academic and government institutions.

Career

Westerhout was born in The Hague, and studied at the University of Leiden (Sterrewacht te Leiden) with Hendrik van de Hulst and Jan Hendrik Oort. Contemporaries and colleagues in Holland included Hugo van Woerden, C. Lex Muller, Maarten Schmidt, Kwee Kiem King, Lodewijk Woltjer, and Charles L. Seeger, Jr. (son of the ethnomusicologist, brother of Pete Seeger and half-brother of Mike Seeger). While they were students, Wim Brouw, Mike Davis, Ernst Raimond, Whitney Shane and Jaap Tinbergen worked with him.

He was awarded Physics and Astronomy degrees: Cand.(1950) and Drs. (1954) and was awarded a Ph.D. in Astronomy and Physics in 1958. Notable scientific achievements included: the significant Westerhout Catalog of continuum emission radio sources, by which "W" numerical designations such sources are still referenced (see for example Westerhout 49), done with the then-new Dwingeloo telescope; and his survey of neutral hydrogen in the outer parts of our Galaxy. His pioneering work, with colleagues, showed the first hints of spiral structure in the interstellar gas, revealed differential rotation in our Galaxy, and established a revised Galactic coordinate system still in use today.

While still at Leiden University, he held the posts of Assistant (1952–56), Scientific Officer (1956–59, and Chief Scientific Officer (1959–62). Arriving in 1962 as the first Director of a fledgling Astronomy Program at the University of Maryland (started by Uco van Wijk), he grew it into a major department granting masters and doctorate degrees. On the research side the Maryland-Green Bank Galactic 21-cm Line Survey, undertaken with the 91-m radio telescope of the National Radio Astronomy Observatory, not only extended to higher angular resolution our knowledge of Galactic structure, but also accomplished the training of graduate students who went on to notable achievements of their own.

He continued at Maryland in that role through 1973, with additional responsibilities from 1972-73 as Chairman of the Division of Mathematical & Physical Sciences and Engineering. From 1973 to '77 he was Professor of Astronomy at the University of Maryland, temporarily becoming Visiting Astronomer at the Max-Planck-Institut für Radioastronomie (MPIfR) in Bonn, Germany 1973-74.

From 1977-1993 he was Scientific Director at the U.S. Naval Observatory in Washington, DC. While there, he guided the evolution of that observatory toward astronomical data obtained from telescopes at the Flagstaff station, astrometric data produced by the techniques of radio interferometry and by innovative application of optical interferometry techniques (ground- and space-based.)

Together with his wife Judith, he had 4 children – Magda Kathleen, Gart, Bridget and Julian.

When Edward L. G. Bowell discovered asteroid 5105 Westerhout, he named it in Westerhout's honor.

Memberships

Memberships include International Astronomical Union (IAU) (Commissions 33, 34, 40, 24 & 5), International Scientific Radio Union (URSI), American Astronomical Society (AAS), Royal Astronomical Society, and Sigma Xi.

He contributed his scientific and management expertise widely, for example to IAU, National Science Foundation (NSF), AAS, National Research Council, Associated Universities Inc., Inter-Union Committee for the Allocation of Frequencies (IUCAF), URSI, National Radio Astronomy Observatory, MPIfR, MIT's Haystack Observatory, Arecibo Observatory, National Academy of Sciences.

Awards

Awards and special recognition have included a NATO Fellowship, CSIRO (Australia) Fellowship, Award for the Teaching of Science, Washington Academy of Sciences, Humboldt Prize, Listings in : Outstanding Educators of America, American Men and Women in Science, Who's Who in America.

Personal recollections

^{[citation needed]}

• Hugo van Woerden: In Westerhout's Leiden years, astronomy students had to go through a long curriculum; each of the three degrees: candidaat, doctorandus and doctor, would require 3–4 years on average. Westerhout entered Leiden University in 1945. Right after his first degree, in early 1950, he started research in radio astronomy, a brand-new, post-war branch of astronomy. He worked with Oort on a model of the Galactic continuum radiation (Westerhout and Oort 1951, BAN 11, 323), and then became heavily involved in the first 21-cm Galactic hydrogen-line studies carried out with the Kootwijk Wurzburg dish. (In a witty after-dinner speech (2002, ASP Conf 276, pp. 27–33) he gave a vivid description of the Kootwijk operations.) After his second degree in 1954, Westerhout was drafted for military service. However, Oort and Van de Hulst successfully argued before the highest State Council that his 21-cm line work was indispensable to the Observatory, and Westerhout was excused from the army after only five months of service (while 18 months was normal). After 1956, using the Dwingeloo 25-meter radio telescope, Westerhout mainly worked on radio continuum studies, including his famous 21-cm source survey, a major 75-cm survey (Seeger, Westerhout, Conway, Hoekema 1965: BAN 18, 11), and early work on polarization of the Galactic background radiation. In 1962 he moved to the University of Maryland, where he became Professor and Director of Astronomy, and returned to Galactic 21-cm line studies with the Green Bank WVA 300-foot meridian telescope. Westerhout's interest in astronomy dates back to his high-school years. Like his contemporaries Schmidt and Van Woerden, he was inspired by Dr. Jean J. Raimond, Director of the Zeiss-Planetarium at The Hague and author of several popular books about astronomy. His father, Gart Westerhout, was an architect and his mother, Magda Foppe, was an author. At his first IAU General Assembly, at Dublin in 1955, Gart met Judith Monaghan, who worked at the Dublin Institute for Advanced studies; they fell in love and were married a year later.

• John D. Curtis, from his University of Maryland years: van Wijk and Westerhout had described how the Ph.D oral defense procedure sometimes occurred in Holland. The candidate might be flanked on either side by two "paranymphs", and upon receiving a question that he might have difficulty with would say: "One moment while I consult with my paranymphs". (Sort of two life-lines.) We found this most amusing, and James J. Rickard (who was about to be subjected to his orals) decided it would be even more memorable if HE was flanked by a couple of paranymphs all duded up in formal black tie dress, perhaps amplifying and distorting the proceeding into something of a caricature. The questioning began and Jim was doing fine until asked by one of the physics professors how can we measure the earth's proper motion through the universe. Jim hadn't a clue, but I knew and it suddenly occurred to me that just for fun the powers that be might allow just one consultation for theatrical effect. I grabbed a pencil and began writing for permission ... the room went dead quiet as everybody watched me, and upon receiving the note, Gart nodded. Jim then saw the note and gave the required "One moment while I..." comment, consulted with both paranymphs, and then explained to the board about looking at the differential red shift of the cosmic background radiation. The board moved on to the next question. I thought it was great, but Gart told me later that he had been almost in a state of shock and couldn't think fast enough to say no. Later, we were paranymphs again for someone else but Gart suggested we not do it again.

• Kurt Riegel: I was Gart's first Ph.D. student at the University of Maryland and it sometimes felt as though we were both making it up as we went along. For example, Gart suggested an efficient dissertation writing procedure that, to my knowledge, had not been employed before. Rather than writing and binding a bulky, excessively annotated and data-packed dissertation for defense, he suggested that we go directly to a version strong and compact enough for publishing directly in the Astrophysical Journal. I was all too happy to comply.

Shortly after his arrival in America, students gaped at his ever-present cigar – he imported Ritmeesters by the barrel from Holland, seemingly every week. Of course, he eventually spurned them but for a time they suggested a flamboyance seldom found among his academic colleagues.
I recall his enthusiasm for flying and his efforts to obtain an aviation license, when justified hiring private airplanes with pilot to carry four people to meetings as he polished his flying skills. One such flight carried us College Park MD to Ann Arbor MI. I was fascinated by the instrument panel, but noticed with horror that the altimeter dial started sweeping counterclockwise, faster & faster – we were dropping like a rock. Even under full-throttle the altimeter still plummeted, because we were in a strong downdraft of a developing storm. Gart and the unconcerned pilot pointed out that even the strongest downdraft must turn horizontal at some point, which of course is what happened as we resumed normal flight. Only later did I learn that the leveling-out maneuver in a downdraft is still dangerous – because of the danger of stalling in a flow that is parallel to the direction of flight!

• Mike Davis: I first met Gart when I arrived at the Sterrewacht te Leiden in September, 1960 as an NSF graduate fellow. I worked with Gart until his departure for Maryland, on compiling a discrete source catalog from the Dwingeloo 400 MHz survey. He and Judith were most helpful getting Jean and me settled into our apartment in Leiden. We even made use of the kolenkachel (coal-burning stove) that they still had in storage from the Suez crisis a few years earlier. We later met up with Gart and Judith in Green Bank, where we moved in 1966. They would come up with their children every summer, to continue the hydrogen observations with the 300 foot telescope. I was the assigned staff adviser for the 300-foot in those days, and much of what I learned and passed on to others came from Gart's experience and advice. We also enjoyed contact with the many Maryland graduate students who worked with Gart on this and other projects in Green Bank.

• Aage Sandqvist: I am forever indebted to Gart for still being in astronomy. Early in my graduate studies, after about a year or so, I was having trouble with some of my Physics courses. During my Christmas holidays, back home in Canada, I came to the conclusion that I didn’t have the brains to achieve a PhD and I arrived back at Maryland at the beginning of 1966 determined to pack my things and go home permanently. I told Gart, my advisor, about my decision to quit. He wouldn’t hear of it! He wouldn’t let me! After a long talk, during which he revealed his own uncertainties as a graduate student in Holland, and his own astonishment at now being the Director of the Astronomy Program at the University of Maryland, he convinced me to NEVER GIVE UP.

Westerhout in College Park, late 1960s

Gart gave me more good advice: One day in our old offices in the Physics building, I was sitting staring at the wall, daydreaming about a girl. Gart walked by and, seeing me in this blank state, asked me what I was doing. “Oh, thinking”, I said, wrinkling my brow a little. Shifting his cigar slightly, he walked on. Next day, I found a new sign on my notice board in front of me which said “DON’T THINK, – WORK!”

Gart and I had one standing conflict, which was never completely resolved: I loved lederhosen; Gart hated lederhosen. Although I could understand his political motivation for this feeling, because I too had (childhood) experiences from an occupied country (my parents were in the Danish resistance movement during WWII), I still thought that he was irrational, and as a Scandinavian and Canadian I suffered immensely from the high temperatures in the Washington area – lederhosen was a cool solution. But Gart didn’t like to see “hairy toes” (a reference to Jim Rickard’s sockless sandals) and “hairy knees” (yours truly) during working hours. So, eventually we reached an uncertain compromise, – no lederhosen during nine-to-five. This was not the end of the lederhosen story, however. That occurred the following summer up at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia. Gart and I were sitting each at a desk in an office working away at the preparation of the next observing session in his Maryland-Green Bank Survey of Neutral Hydrogen in the Milky Way Galaxy. I had my back to the door and to Gart, when suddenly I heard him grunt. I looked around at him. I think he had swallowed his cigar. He was looking at the doorway, pale and eyes bulging. I looked at the door – and there stood Gart’s new student, Ron Harten, wearing ... lederhosen, practically identical to mine. “Not another one!” was his desperate whisper.

My last little story concerns Karin (my wife) and myself. Karin came from Sweden in the beginning of 1968 and we lived together as husband and wife without actually getting married until 1971, when we did marry. This was standard procedure in Scandinavia, but certainly not in the US in those days. One problem arose in connection with an observation run at Green Bank, because I wanted to show Green Bank to Karin and have her come along. “Only accompanying wives (and mothers, I think) are allowed in the dormitory at Green Bank” I was told authoritatively by NRAO. What to do? Well, we took a small tent along and pitched it in the little woods at the end of the Green Bank runway. I went from there to my observing session at the 140-foot telescope. While I was sitting at the control desk the first day, the phone rang and John Findlay (who was the Green Bank director at that time) was on the other end: “Sandy, you bloody idiot, why didn’t you tell a lie, and say that Karin was your wife. You’ll have to pull down the tent immediately. This observatory must be perfect. And just to let you know that I understand you, we will give YOU one room and Karin a separate room at the dorm, THIS time only”. Well, how does Gart come into this? Gart arrived by plane that same day and was greeted at the runway by a very excited Wally Oref, who was in charge of Green Bank morality and other administrative matters. “What are you going to do about that Sandqvist?” Wally cried out before Gart even got his foot on the tarmac. “What’s Sandy done now?” was Gart’s reply, and he was told in probably no uncertain terms. So, Gart and Sandy had another talk, about morality, culture, national characteristics – a very friendly talk it turned out to be. Gart’s last comment to me, as I left his office, was “... and oh, by the way, Sandy, whatever you do, just make darn sure that at least one bed in EACH room is messed up every morning!”

http://photos.aip.org/history/Thumbnails/laster_howard_c1.jpg

Bibliography

A. Papers published in refereed journals

l. Astronomy research

• "A Comparison of the Intensity Distribution of Radio-Frequency Radiation with a Model of the Galactic System," (with J. H. Oort), Bull. Astron. Inst. Neth., 11, 323, 1951.
• "The Rotation of the Inner Parts of the Galactic System," (with K. K. Kwee and C. A. Muller), Bull. Astron. Inst. Neth., 12, 211, 1954.
• "Search for Polarization of the Crab Nebula and Cassiopeia A at 22 cm Wavelength," Bull. Astron. Inst. Neth., 12, 309,1956.
• "The Flux Densities of some Radio Sources at 400 Mc/s," (with C. L. Seeger and H. C. van de Hulst), Bull. Astron. Inst. Neth., 13, 89, 1956.
• "Continuous Radiation from the Direction of the Galactic Centre at 22 cm," Bull. Astron. Inst. Neth., 13, 105, 1956.
• "A Catalogue of 21-cm Line Profiles," (with C. A. Muller), Bull. Astron. Inst. Neth., 13, 151, 1957.
• "The Distribution of Atomic Hydrogen in the Outer Parts of the Galactic System," Bull. Astron. Inst. Neth., 13, 201, 1957.
• "Observations of Occulations of the Crab Nebula by the Moon at 400 Mc/s," (with C. L. Seeger), Bull Astron. Inst. Neth., 13, 312, 1957.
• "Intensites Relatives des Quatre Principales Radiosources Observees sur la Longueur d'Onde 22 cm; Note sur la Radiosource Saggittarius A", Compt. Rend. Acad. Sci. Paris, 245, 35, 1957.
• "Observations of Discrete Sources, the Coma Cluster, the Moon, and the Andromeda Nebula at a Wavelength of 75 cm.," (with C. L. Seeger and R. G. Conway), Astrophys. J., 126, 585, 1957.
• "A Survey of the Continuous Radiation from the Galactic System at a Frequency of 1390 Mc/s," Bull. Astron. Inst. Neth., 14, 215, 1958.
• "Note on the Density of Ionized Hydrogen in the Galactic System," Bull. Astron. Inst. Neth., 14, 261, 1958.
• "The Galactic System as a Spiral Nebula," (with J. H. Oort and F. J. Kerr), Monthly Notices Roy. Astron. Soc., 118, 379, 1958.
• "The New I.A.U. System of Galactic Coordinates," (with A. Blaauw, C. S. Gum and J. L. Pawsey), Monthly Notices Roy. Astron. Soc., 121, 123, 1960.
• "A 21-cm Determination of the Principal Plane of the Galaxy," (with C. S. Gum and F. J. Kerr), Monthly Notices Roy. Astron. Soc., 121, 132, 1960.
• "Die Durchmusterung Der Milchstrasse Und Die Quellendurchmusterung Bei 2.7 Gllz," (with W. Altenhoff, P. G. Mezger and H. Wendker), Veroffentl. Sternwarte 59, Bonn, November 1961.
• "The Polarization of the Galactic 75-cm Radiation," (with C. L. Seeger, W. N. Brouw and J. Tinbergen), Bull. Astron. Inst. Neth., 16, 187, 1962.
• "The Structure of the Galaxy from Radio Observations," I.E.E.E. Trans., AP-12, 954, 1964.
• "A Survey of the Continuous Radiation at 400 Mc/s," (with C. L. Seeger, R. G. Conway and T. Hoekema), Bull. Astron. Inst. Neth., 18, 11, 1965.
• "A Catalogue of Discrete Sources Observed at 400 Mc/s," (with M. M. Davis and L. Gelato-Volders), Bull. Astron. Inst. Neth., 18, 42, 1965.
• "21-cm Line Emission in Open Clusters," (with W. E. Howard and C. Gordon), Astrophys. J., 154, 103, 1968.
• "The Maryland – Green Bank Galactic 21-cm Line Survey" (with H.-U.Wendlandt), Astron. Astrophys. Suppl. 49, 143, 1982.
• "Telescope Beam Characteristics and Temperature Scale of the Maryland- Green Bank 21-cm Line Survey" (with G.L.Mader and R.H.Harten), Astron. Astrophys. Suppl. 49, 137, 1982.
• "Astrometry and Precise Time", with G.M.R.Winkler, Oceanus 33, 89–95. 1991

2. Instrumentation or techniques

• "Table for the Reduction of Velocities to the Local Standard of Rest" (with D. A. MacRae), The Observatory, Lund, Sweden, 1956.
• "A Method for Accurately Compensating for the Effects of the Error Beam of the NRAO 300-foot Radio Telescope at 21-cm Wavelength," (with H.-U. Wendlandt and R. H. Harten), Astron. J., 78, 569, 1973.
• "Hydrogen 21-cm Line Temperature scale", (with R.H.Harten and F.J.Kerr), Astron.J., 80, 307, 1975

B. Papers presented at scientific meetings

1. Invited papers

• "Kosmische Bronnen Van Radiostraling," (with H. C. van de Hulst), Sterr. Coll. Ned. Astr. Club., 13, 1956.
• "A 21-cm Line Survey of the Outer Parts of the Galaxy," In IAU Symp. 4, ch. 5, Cambridge Univ. Press, 1957.
• "Progress Report on 21-cm Research by the Netherlands Foundation for Radio Astronomy and the Leiden Observatory," In IAU Symp 4, ch. 4, Cambridge Univ. Press, 1957.
• "Galactic Radiation and its Physical Interpretation", Introductory Report, Comm. V, URSI 13th General Assembly, London, 1960.
• "A Summary of our Knowledge of the Neutral Hydrogen in Galaxies", In Problems of Extra-Galactic Research, McMillan and Co., New York, 1962.
• "Current Radio Astronomical Research in the Netherlands", Proc.I.R.E. Austr., 24, 214, 1963.
• "The Interpretation of Recent 21-cm Line Data in Terms of Large-Scale Galactic Structure," IAU Symp. 20, Australia, 1963.
• "Observation and Interpretation of Optical and Radio Polarization," IAU Symp. 20, Australia, 1963.
• Three Years of Galactic Radio Astronomy," Proc. of URSI General Assembly, Tokyo, 1963.
• "Brightness Temperatures Expected for a Radio Telescope with High Resolving Power," In Proc. OECD Symp. on Large Antennae, Paris, 1963.
• "Site Requirements, In Proc. OECD Symp. on Large Antennae, Paris, 1963.
• "The Early History of Radio Astronomy", In International Conference on Education in and History of Modern Astronomy, ed. R. Berendzen, Ann. New York Acad. Sci., 198, 211, 1972.
• "Some Remarks on the Ideal Automated Observatory," In NRAO/IEEE/URSI Symp. on the Collection and Analysis of Astrophysical Data, ed. R. Burns, Astron. Astrophys. Suppl., 15, 327, 1974.
• "The Influence of Acquisition Techniques on the Compilation of Astronomical Data", in IAU Colloquium 35 on Data Compilation, Strasbourg 1976, ed. Jaschek and Wilkins, Reidel, Dordrecht, Astrophys. and Space Sc. Lib 64, 49, 1977
• "Future Development in U.S. Naval Observatory Time Services",

Proc. 9th Ann. PTTI meeting, NASA Tech. Mem. 78104, 1, 1978

• "Radio Astrometry and Other Accurate Astrometry Plans at the U.S. Naval Observatory", ESA Colloquium on European Satellite Astrometry, Padua, Ed. C.Barbiery and P.L.Bernacca, Universita di Padova 1979
• "Space Astrometry – its Impact on Astronomy and Astrophysics", Highlights of Astronomy Vol.5, 779, Ed. P.A.Wayman, Reidel Dordrecht 1980
• "Early Dutch Radio Astronomy", URSI General Assembly Comm. J, Washington 1981, Ed. W.T.Sullivan (not published).
• "The Pioneers of HI", in "Seeing through the Dust", eds. A.R.Taylor, T.L.Landecker, A.G.Willis, Astron. Soc. Pacific Conf.Ser. 276, 3, 2002
• "The Start of 21-cm line Research: the Early Dutch Years", in "Seeing Through the Dust", eds. A.R.Taylor, T.L.Landecker, A.G.Willis, Astron. Soc. Pacific Conf.Ser. 276, 3, 2002

2. Contributed papers

• "75-cm and 22-cm Continuum Surveys," In IAU Symp. 9, ch. 80, Stanford Univ. Press, 1959.
• "75-cm Galactic Background Polarization: Progress Report," (with W. N. Brouw, C. A. Muller and J. Tinbergen), Astron. J., 67, 590, 1962.
• "Radio Studies of HII Regions and Galactic Structure," (with M. Komesaroff), IAU Symp. 20, Australia, 1963.
• "Galactic 21-cm Iine Observations at Green Bank," Astron. J., 69, 152, 1964.
• "Preliminary Observations of 21-cm Line Emission in Open Clusters," (with W. L. Howard), Astron. J., 70, 688, 1965 (Abstract).
• "The Maryland-Green Bank Galactic 21-cm Line Survey'", IAU Symp. 31, Noordwijk, Netherlands, 173, Acad. Press, 1967.
• "A Motion Picture Film of Galactic 21-cm Line Emission," IAU Symp. 38, paper 19, ed. G. Contopoulos and R. Becker), Reidel, Dordrecht, 1970.
• "A High-Resolution Polarization Survey of the North Polar Spur," (with D. Bechis), ln IAU Symp. 60, ed. F. J. Kerr and S. C. Simonson, Springer Verlag, 1974.
• "Progress Report on the Maryland-Green Bank Galactic 21-cm Line Survey, In IAU Symp. 60, ed. F. J. Kerr and S. C. Simonson, Springer Verlag, 1974.
• "The U.S.Naval Observatory Parallax Program" (with R.H.Harrington), Bull. d'Inf. Centre de Donnees Stell. 20, 24, 1981
• "Data on Time and Polar Motion: Immediate Accessibility" (with D.D.McCarthy), I.A.U. Colloq. 64, Automated Data Retrieval in Astronomy, Strasbourg, Ed. C.Jaschek, Reidel Dordrecht, 1982
• "U.S.Naval Observatory Parallaxes and the Fundamental Reference Frame – their Interaction with Hipparcos" (with J.A.Hughes), ESA Colloquium on Space Astrometry, Strasbourg 1982
• "Concluding Remarks," in IAU Symposium 109, Astrometric Techniques, H.K. Eichhorn and R. J. Leacock (eds), Reidel Dordrecht, 799–803, 1986
• "Fricke's Influence on the World of Astronomy," Celestial Mechanics 37, 345–348, 1985
• "The USNO/CALTECH Measuring Program" (with D. Monet), Bull d'Information du CDS 37, 75–78, 1989
• "Concluding Remarks," Bull d'Information du CDS 37, 91–92, 1989
• "Astrometry: New Vitality for an Ancient Science," Aerospace America 27, No. 10, 34–37, 1989
• "The Flagstaff Measuring Machine" (with D. Monet), in IAU Symposium 141, Inertial Coordinate System on the Sky, J.H.Lieske and V.K.Abalakin, Eds., Kluwer Dordrecht 1990
• "Concluding Remarks", in IAU Symposium 141, Inertial Coordinate System on the Sky, J.H.Lieske and V.K.Abalakin, Eds, Kluwer Dordrecht, 1990

C. Books or contributions to edited books

• "The Radio Galaxy," Sci. Am., 201, 45, 1959.
• "The Mapping of the Galaxy, In Tomorrow was Yesterday, C.B.S., George Braziller, New York, 1964.
• "Distribution of Interstellar Hydrogen," (with F. J. Kerr), ch. 8, in Stars and Stellar Systems, vol. 5, p. 166, Univ. of Chicago Press,1965
• "Radio Emission of the Galaxy," Comm. 40 report, IAU Trans. XII A, Acad. Press, 1965.
• "Galactic Radio Astronomy," Comm. 40 reports on Astronomy, lAU Trans. XIVA, 460, Reidel, Dordrecht – Holland, 1970.
• "Galactic Radio Emission in the 21-cm Line and the Continuum," In Galactic Astronomy, ed. H. Y. Chiu and A. Muriel, pp. 147–190, Gordon and Breach, 1971.

D. Technical reports and others

• "The Maryland-Green Bank Galactic 21-cm Line Survey," first edition, University of Maryland, Department of Physics and Astronomy, 1966.
• "Maryland-Green Bank 21-cm Line Survey," second edition, University of Maryland Astronomy Program, 1969.

References

External links

• Things Unseen: The Westerhout radio sources
• Howard Laster, Joseph Weber & Gart Westerhout in College Park, late 1960s