WALTER H. G. LEWIN, Professor
of Physics
Research Interests
From 1960 to 1965, Prof. Lewin carried out research in low-energy
nuclear physics in The Netherlands. In 1966, he joined the MIT
X-ray Astronomy Group. With George
Clark he conducted all-sky balloon surveys (>25 keV) from
the Northern and Southern hemispheres (1967-69). This led to the
discovery in 1967 of the first rapid X-ray variation, a flare from
Sco X-1 lasting ~30 minutes. From 1970 to 1980, he directed the
MIT balloon group and discovered (in 1970-71) the first slowly rotating
X-ray pulsar GX 1+4.
Lewin was co-investigator on the SAS-3 project, in which he directed
the burst observations that discovered several X-ray bursters, among
them the Rapid Burster, which, when active, can produce more than
5,000 bursts per day. His group also discovered that the Rapid Burster
produces two types of bursts and established a classification of
bursts as type I (thermonuclear flashes) and type II (accretion
flow instabilities).
Lewin was Co-Principal Investigator on HEAO-1 (A4), which has yielded
the first all sky catalog at high-energy (>25 keV) X rays. With
H. Pedersen and J. van Paradijs, Lewin made extensive studies of
optical bursts which are associated with X-ray bursts; for X-ray
detections they used SAS-3 and the Japanese Observatory "Hakucho".
Their combined burst observations demonstrated that the optical
bursts are a few seconds delayed relative to the X-ray bursts. This
established the size of the accretion disc surrounding the accreting
neutron stars.
In his search for millisecond X-ray pulsations from low-mass X-ray
binaries, in 1984-85 Lewin made guest observations with the European
Observatory EXOSAT in collaboration with colleagues from Amsterdam
and Garching, Germany. This led to the unexpected discovery of intensity-dependent
quasi-periodic X-ray oscillations (QPO) in the X-ray flux of GX
5-1. During 1989 to 1992, using the Japanese Observatory "Ginga",
Lewin and his co-workers have studied the relation between the X-ray
spectral state and the radio brightness of several bright low-mass
X-ray binaries.
Lewin was closely involved in ROSAT
observations of the nearby galaxies M31 and M81. Lewin and his graduate
student Eugene Magnier have made deep optical CCD observations of
M31 (complete to approximately 21 mag) in four colors; they have
published a catalogue (~1" positions) of 500,000 objects. To
date, already ~100 optical identifications have been made of the
~400 X-ray sources in the field of M31. Lewin initiated the successful
X-ray observations (with ROSAT)
within six days of the appearance of supernova SN 1993J in M81.
Since 1978, Lewin has collaborated with his close friend Jan van
Paradijs of the University of Amsterdam with whom he has co-authored
150 papers. This collaboration has been a highlight in Lewin's life
(see the article, "My
Quarter Century with Jan").
Lewin and graduate student Jeffrey Kommers have worked on data
from the Compton Gamma-ray Observatory (GRO). This was a collaboration
with the BATSE Group in Huntsville, AL. In early December 1995,
with co-workers Kouveliotou and Van Paradijs, they discovered a
new type of X-ray burst source (GRO J1744-28; the Bursting Pulsar).
They received a NASA Achievement Award for this discovery.
Lewin's collaboration with Professor Van der Klis in Amsterdam
led to the discovery of kHz oscillations in many X-ray binaries
(1996-1998). The origin of these oscillations is still not understood.
During the past six years, using the Chandra Observatory, Lewin
and his graduate student (now Dr. Dave Pooley), have made extensive
studies of supernovae, and of the faint X-ray sources in Globular
Clusters. This research (which is still ongoing) is done in collaboration
with scientists from the University of Washington (Seattle), IAS
in Princeton, UC Berkeley, the University of Amsterdam and Utrecht
in The Netherlands, and the Naval Research Laboratory (Washington,
DC). The research on supernovae produced the first X-ray spectrum
with unprecedented energy resolution of SN 1989S. The research on
Globular Clusters demonstrated that X-ray binary stars are cooked
in the cores of the clusters where the stellar density is very high.
This has been suspected for almost three decades, but we now have
unambiguous evidence (see Selected Publications,
below).
With graduate student Jon Miller (now Dr. Miller) Lewin made extensive
studies of black-hole X-ray binaries in our galaxy. Evidence was
found for spectral distortions of the iron line (in X-rays) indicative
of the influence of general relativity on the iron-line emission
in the vicinity of the "event horizon" of the black holes.
This research on black-hole binaries is continuing using all available
observatories in orbit: Chandra, the Rossi X-ray Timing Explorer
(RXTE), and the European observatories XMM-Newton and Integral.
In 2005, "Compact Stellar X-ray Sources" will be published by Cambridge
University Press. This book is a natural follow-up on its predecessors, "Accretion-driven Stellar X-ray Sources" (1983) and "X-ray Binaries" (1995).
Lewin is the main editor on these standard reviews in X-ray Astronomy.
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Teaching Interests
Lewin's lectures at MIT are legendary. Many have been shown for
over six years on UWTV in Seattle, reaching an audience of about
four million people. He personally responded to all e-mail requests
he received (hundreds per year) from UWTV viewers, who varied in
age from 7 to 90. For fifteen years he was on MIT Cable TV helping
freshmen with their weekly homework assignments. His programs, which
were aired 24 hours per day, were also frequently watched by upper-class
students. Lewin is the soul of PIVoT,
a video course on Newtonian
Mechanics with a total of 53 hours of video clips. Additionally,
his 36 lectures on Electricity
and Magnetism and 23 lectures on Vibrations and Waves can also be viewed from the course's web site.
Finally, his special lectures given at MIT for science teachers
and for middle school students can be viewed on MIT
World.
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Biographical Sketch
A native of The Netherlands, Professor Lewin received his Ph.D.
in Physics from the University of Delft (1965). In 1966, he came
to MIT as a postdoctoral associate in the Department of Physics
and was invited to join the faculty as an Assistant Professor later
that same year. He was promoted to Associate Professor of Physics
in 1968 and to full Professor in 1974.
Professor Lewin's honors and awards include the NASA Award for
Exceptional Scientific Achievement (1978), twice recipient of the
Alexander von Humboldt Award (1984 and 1991), a Guggenheim Fellowship
(1984), MIT's Science Council Prize for Excellence in Undergraduate
Teaching (1984) and the W. Buechner Teaching Prize of the MIT Department
of Physics (1988). In 1997, he was the recipient of a NASA Group
Achievement Award for the Discovery of the Bursting Pulsar.
He is a member of the Royal Dutch Academy of Sciences (elected
1993), Fellow of the American Physical Society.
In the seventies and eighties Lewin collaborated with the artists
Otto Piene
(born in Germany), who was for many years the Director of MIT's
Center for Advanced Visual Studies, and with Peter
Struycken (Dutch) who is one of the leading computer artists
in the world.
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Selected Publications
"Observation of an X-Ray Flare from Sco X-1," W.H.G.
Lewin, G.W. Clark and W.B. Smith, Astrophysical Journal (Letters)
152, L55 (1968).
"X-Rays from a New Variable Source GX 1+4," W.H.G. Lewin,
J.E. McClintock and G.R. Ricker, Astrophysical Journal (Letters)
169, L17 (1971).
"The Discovery of Rapidly Repetitive X-Ray Bursts from a New
Source in Scorpius," W.H.G. Lewin, J. Doty, G.W. Clark, S.
Rappaport, H.V.D. Bradt, R. Doxsey, D.R. Hearn, J.A. Hoffman, J.G.
Jernigan, F.K. Li, W. Mayer, J. McClintock, F. Primini, J. Richardson,
Astrophysical Journal (Letters) 207, L95 (1976).
"Dual Character of the Rapid Burster and a Classification
of X-Ray Bursts," J. Hoffman, H. Marshall and W. Lewin, Nature
271, 630 (1978).
"Discovery of Optical Bursts from an X-Ray Source, MXB 1735-44,"
J.E. Grindlay, J.E. McClintock, C.R. Canizares, J. van Paradijs,
L. Cominsky, F.K. Li and W.H.G. Lewin, Nature 274,
567 (1978).
"Evidence for a Four-Hour Optical Period in 4U/MXB 1636-53,"
H. Pedersen, J. van Paradijs, W.H.G. Lewin, Nature 294,
725 (1981).
Exchange of Letters between W.H.G. Lewin and Panamarenko in "Struycken
and Panamarenko" Catalogue, Studium Generale, T.H. Eindhoven,
The Netherlands (1981).
"Precursors to X-Ray Bursts, the Result of Expansion and Subsequent
Contraction of the Neutron Star's Photosphere," W.H.G. Lewin,
W.D. Vacca, and E.M. Basinska, Astrophysical Journal (Letters),
277, L57, (1984).
"Discovery of Intensity-Dependent Quasi-Periodic Oscillations
in the X-Ray Flux of GX 5-1," M. van der Klis, F. Jansen, J.
van Paradijs, W. H. G. Lewin, E. P. J. v. d. Heuvel, J. E. Truemper,
and M. Sztajno, Nature, 316, 225 (1985).
"Quasi-Periodic Oscillations in the X-Ray Flux of the Rapid
Burster (MXB 1730-335)", L. Stella, F. Haberl, W.H.G. Lewin,
A. Parmar, J. v. Paradijs, and N.E. White, Astroph. Journal,
324, 379, (1988).
"A New Kind of Oscillations in the Persistent Emission of
the Rapid Burster", L.M. Lubin, W.H.G. Lewin, R.E. Rutledge,
J. v. Paradijs, M. v.d. Klis, and L. Stella, Monthly Not. Roy.
astron. Soc., 258, 759, (1992).
"X Rays from SN 1993J," H.-U. Zimmermann, W.H.G. Lewin,
P. Predehl, B. Aschenbach, G. Fabbiano, G. Hasinger, L.M. Lubin,
E. Magnier, J. van Paradijs, R. Petre, W. Pietsch, and J. Truemper,
Nature, 367, 621, (1994).
"Three Decades of X-Ray Astronomy from the Point of View of
a Biased Observer," W.H.G. Lewin, "The Evolution of X-Ray
Binaries", AIP Conference Proceedings 308, eds.
S.S. Holt & C.S. Day, American Institute of Physics, page 3,
(1994).
"X-ray Bursts," W.H.G. Lewin, J. van Paradijs & R.
Taam, in: X-ray Binaries, eds. W.H.G. Lewin, J. van Paradijs
& E.P.J. v.d. Heuvel, Cambridge Univ. Press, p. 175, (1995).
"Black-Hole Binaries," Y. Tanaka & W.H.G. Lewin,
in: X-ray Binaries, eds. W.H.G. Lewin, J. van Paradijs &
E.P.J. v.d. Heuvel, Cambridge Univ. Press, p. 126, (1995).
"Discovery of a New Type of Burster from the Galactic Center
Region," C. Kouveliotou, J. van Paradijs, G. J. Fishman, M.
S. Briggs, J. Kommers, B. A. Harmon, C. A. Meegan, W. H. G. Lewin,
Nature, 379, 799, (1996).
"Discovery of Sub millisecond Quasi-periodic Oscillations
in the X-ray Flux of Scorpius X-1", M. v.d. Klis, J. Swank,
W. Zhang, K. Jahoda, E. Morgan, W. Lewin, B. Vaughan, & J. van
Paradijs, Astrophys. Journal., 469, L1, (1996).
"Traces of Science in Art" ("Sporen van Wetenschap
in Kunst"). Invited Talk presented (in Dutch) LIVE FROM BOSTON
at the opening of the Art Exhibit at the Royal National Academy
of Sciences (KNAW) in Amsterdam, The Netherlands, June 26 (1998).
The Art Catalogue Published by the Royal National Academy of Sciences
(KNAW), (1998).
"My Two Decades with Joachim", in: "Highlights in
X-ray Astronomy", International Symposium in honor of Joachim
Truemper's 65th birthday, June 17-19, 1998, MPE Report 272,
ISSN 0178-0719, May 1999, page 7-15, (1999).
"Optical Identifications of Multiple Faint X-ray Sources in
the Globular Cluster NGC~6752: Evidence for Numerous Cataclysmic
Variables'', D. Pooley, W. Lewin, L. Homer, S. Anderson, B. Gaensler,
B. Margon, F. Verbunt, J. Miller, D. Fox, V. Kaspi & M. v.d.
Klis, astro-ph/0110192, Astrophys. Journal, 569, 405,
2002.
"Resolving the Composite Fe K-alpha Emission Line in the Galactic
Black Hole Cygnus X-1 with Chandra,'' J. Miller, A. Fabian, R. Wijnands,
R. Remillard, P. Wojdowski, N. Schulz, T. Di Matteo, H. Marshall,
C. Canizares, & W. Lewin, astro-ph/0202083, Astroph. J.,
578, 348, 2002.
"X-Ray Supernovae,'' Stefan Immler & Walter H.G. Lewin,
Lecture Notes in Physics, In: Supernovae and Gamma-ray Bursts,
ed. Kurt Weiler, Springer Verlag, 2003, p. 91.
"My Quarter Century with Jan'', Walter H.G. Lewin, Proceedings
of the Jan van Paradijs Memorial Symposium, astro-ph/0105344.
"From X-ray Binaries to Gamma-ray Bursts," ASP Conference Series Vol. 308,
eds. E.P.J. van den Heuvel, L. Kaper, E.Rol, R.A.M. Wijers, page 27-57, 2003.
"Dynamical Formation of Close Binary Systems in Globular Clusters,''
D. Pooley, W.H.G. Lewin, S.F. Anderson, H. Baumgardt, A.V. Filippenko,
B.M. Gaensler, L. Homer, P. Hut, V.M. Kaspi, B. Margon, S. McMillan,
S. Portegies Zwart, M. van der Klis, & F. Verbunt, Astrophys.
J., 591, L131, 2003, astro-ph/0305003.
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