Professor at the Department of Mechanics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Greece. He was born in Corinth, Greece, on the 12th of July, 1947. He received the B.Sc. in Mathematics from the University of Athens, Greece (1971) and the Ph.D. in Physics from the University of Patras, Greece (1975). He worked as a researcher at this University (1975-77), as Senior Assistant (1978-1982), Lector (1982-1985), Assistant Professor (1985-1993)
￼￼￼￼￼￼￼￼￼and Associate Professor (1993 – 2009) of the former General Department of the National Technical University of Athens. Since 1978 he is also Professor at the School of Technical Education for Army officers. His scientific interests include Celestial Dynamics, Electrodynamics, the Dynamics of the Absolute Solid and the Dynamics of Complex Solid Systems and he has published more than 100 papers on these subjects. He has also published three textbooks on the “Stability of the Dynamical Systems”, the “Absolute Solid” and “Analytical Dynamics”. He has close scientific collaboration with the University of Liverpool (U.K.) and he has worked there as a Research Fellow.
He was born in Kavala, Greece, on the 16th of September, 1928 and passed away in 2011. He received the B.Sc. in Mathematics from the AUTH (1949) and the Ph.D. in Astronomy from the same University (1954). He worked as Assistant (1951-1955) and Chief Assistant (1955-1960) at the Laboratory of Astronomy of the same University and as Director of the Research and Computing Center of the Academy of Athens (1960-1966). He was elected Professor of Geodetic Astronomy and Director of the respective Laboratory, School of Engineering, AUTH (1964-1966). He has been elected twice Dean of the School of Engineering of the AUTH (1967-1968 and 1970-1973), Vice- Rector of the AUTH, Founding Rector of the Democritus University of Thrace (1974-78), President of the State Scholarship Foundation (IKY) (1976-1978) and General Director of Higher Education of the Greek Ministry of Education and Cults (1978-1979). He is the Founder and the Director of the Stephanion Observatory (since 1966). His research work refers to Astronomy, Astrophysics, Geodesy, Geophysics, Space Science and Applications and, later, to Initial and Continuing Education and Training with Distance Learning. He has published more than 110 scientific papers in refereed journals and more than 20 papers in conference proceedings and special volumes/books. He has been Editor or coeditor in four volumes (“Observational Aspects of Galactic Structure”, “Structure & Evolution of the Galaxy”, "Stars and the Milky Way System”, “Compendium in Astronomy” and “Earthquake Prediction and Instrumentation”). He has published (in Greek) many textbooks and notes for the University students on Astronomy, Geodesy and Error Theory. He has been named Honorary Doctor of the Democritus University of Thrace, Department of Electrical and Computer Engineering (1995) and Department of Civil Engineering (1996). He is corresponding Member of the Academy of Athens (since 1988) and of the Academy of Sciences of Heidelberg (since 1988) and an active member of the N.Y. Academy of Sciences (1995). He has been honored by the President of the Greek Republic with the “Officer of the Order of the Phoenix” (1977) and by the President of the F.R. of Germany with the “Grosser Verdienst- Kreuz des Verdienst- Ordens der Bundesrepublik Deutschland” (1988).
￼The Academy of Athens awarded him the “Excellence of the Sciences”, the highest distinction in this field (1986). He is a member of the International Astronomical Union (IAU- President or Member in many organizing Committees of Commissions 27, 33, 46, 37 and of the Special Study Group 1.78), of the Astronomische Gesellschaft, of the American Astronomical Society, of the Astronomical Society of the Pacific, of the Royal Astronomical Society and of the Hellenic Astronomical Society. He has served as member in Greek National Committees (on Geodesy and Geophysics, on Astronomy and on Space Research). He has been a Member of the Group of U.N. Experts on the Geographical Names and President of its Third Conference and National Representative of Greece to the “Space Committee” of the European Commission.
Professor Emeritus, Department of Physics, University of Athens, Greece (since 1999). She was born in Egion,
Achaias, Greece and obtained her B.Sc. in Physics
(1970), the M.Sc. in Meteorology (1976) and the Ph.D. in
Physics (1978) from the University of Athens, Greece.
She worked as an assistant at the Nuclear Physics
Laboratory (1970-82) and as Lecturer (1982) and
Assistant Professor (1985) at the same University. She is
a scientific collaborator (since 1979) of the Research
Center of Astronomy and Applied Mathematics of the
Academy of Athens. She has written one textbook on
“Cosmic Rays” and co-authored two other textbooks on
“Nuclear Physics” and “Atomic Physics”. She is the Head of the Cosmic Ray Group of Athens University from 1982 of undergraduate and graduate students as well as of post graduate and scientific researchers. Her scientific interests include Galactic and Solar Cosmic ray Physics, Magnetospheric Physics, Space Physics, Space Weather monitoring by cosmic rays, Neutron Monitors and satellite data analysis. She is Scientific Responsible of the Installation and Operation of the Athens Neutron Monitor Station in real-time (2000-) and Head of the Athens Neutron Monitor Data Processing (ANMODAP) Center (2003-today), an Alert system providing a warning signal worldwide in real-time for GLE events is operated since 2003.
Professor (retired), Technological Educational Institute (TEI) of Kavala, Greece. He was born in Kavala on the 2nd of February, 1945. He obtained his B.Sc. in Physics from the Aristotle University of Thessaloniki, Greece (1968), an M.Sc. in Meteorology from the University of Athens, Greece (1972) and a second M.Sc. in Radioelectrology from the University of Thessaloniki (1974). He received the Ph.D. in Astrophysics from the same University. He is a member of the International Astronomical Union (IAU), of the IEEE and of the Hellenic Astronomical Society (Hel.A.S.).
Angelos Misiriotis was born in Athens (Greece) on November 6, 1971. He obtained his BSc in Physics from the University of Patras in 1995 and his PhD in Theoretical Astrophysics in 2001, from the Dept. of Physics of the University of Crete, under the supervision of Prof. Nick Kylafis. During his PhD studies he spent two years at the Observatory of Marseille, where he collaborated with Dr. Lia Athanassoula and her group.
His research interests included the morphology and dynamics of spiral galaxies and until his passing away on January 4, 2008 at the age of 37, he had published 12 refereed papers in these areas. He is survived by his wife Anastasia and his children Nestor and Iro.
Dimitri M. Mihalas (1939 - 2013)
Dimitri Mihalas died on Thursday the 21st of November 2013.
World-renowned astrophysicist Dimitri Mihalas passed away in his sleep at his home in Santa Fe, New Mexico on November 21, 2013. Dr. Mihalas retired from the University of Illinois at Urbana- Champaign in 1999 and from the Los Alamos National Laboratory in 2012. Dimitri, to his friends and family, has donated his body to the University of New Mexico Medical School and his library to New Mexico Tech.
Dimitri was born on March 20, 1939 in Los Angeles, California where he grew up. He received his B.A., with Highest Honors, in three majors, Physics, Mathematics, and Astronomy, from the University of California at Los Angeles at age 20. Four years later he received his Ph.D. in Astronomy and Physics from the California Institute of Technology. He was a pioneer in computational astrophysics, and has remained a world leader in the fields of radiation transport, radiation hydrodynamics, and astrophysical quantitative spectroscopy for decades. His broad knowledge and immense contributions earned him election to the U.S. National Academy of Sciences in 1981 at age 42.
Dimitri had an exceptional record of work. He published more than 150 papers and technical reports, authored or co-authored eight books, and co-edited three others. Three of his books have been used as textbooks for both undergraduate and graduate students worldwide and have been translated into other languages, including Russian. His book Foundations of Radiation Hydrodynamics has become the “bible” of the radiation hydrodynamics community.
Dimitri wrote his Ph.D. thesis on theoretical modelings for hydrogen and helium line strengths and profiles in O-stars. He interpreted the observational data with the best theoretical analysis possible at the time. The models were computed using the then prevailing simplifying approximation of local thermodynamic equilibrium (LTE). As shown by its high number of citations, this work, primitive by todays standards, had a major impact on the field.
After joining the faculty of the Department of Astrophysical Sciences at Princeton University, Dimitri undertook new analyses of stellar abundances, devised a method for constructing a constant-flux atmosphere with convection in the full transport (not diffusion) regime, computed the first line-blanketed spectrum of a hot B star which showed that continuum- only models overestimated the effective temperature by 10% (hence luminosity by 40%), and computed a sample of H line-blanketed models accounting for the distortion of the continuum by the confluence of the hydrogen Balmer lines near 3650Å.
Dimitri realized that the widely accepted approximation of LTE in stellar atmospheres is inadequate, so he undertook a major initiative to solve the analogous non-LTE problem. This is an exceptionally difficult problem owing to the need to solve self-consistently a set of coupled, highly nonlinear effects. Only the highly idealized case of a two-level atom with a single line and two continua had been solved previously.
After several preliminary explorations of methodology with Auer, they reformulated the non-LTE stellar atmosphere problem in a completely original manner; applying the Newton- Raphson technique to the full nonlinear system, and iterating to convergence. This method was a breakthrough in the field – it revolutionized all further work on computing stellar atmospheres. Through his idea of “variable Eddington factors,” the method was made even more efficient.
With this new methodology, Dimitri constructed an extensive, widely cited, sample of non-LTE models for hot stars, and used them to evaluate the effects of departures from LTE on observable stellar line and continuum indices. These results allowed Mihalas and Auer to perform several critical studies which were not previously possible, achieving for the first time good agreement between the computed and observed strengths of the hydrogen and helium lines, and surface gravities consistent with the stars observed masses and element abundances obtained
from nebular analyses. This work has been widely cited, both for the quality of fit to observations, as well as a “gold standard” for verification of present-day calculations using much faster iterative methods. Work with Hummer led to the discovery of the physical mechanism producing the emission the N III emission lines at wavelengths 4634 – 4650Å in O((f)) stars.
In the 1970s, Dimitri devised the now standard method for solving the line-transfer problem in expanding spherical atmospheres in the comoving frame. This work was summarized in the heavily cited 2nd edition of his textbook Stellar Atmospheres, which remains the standard in the field even after 25 years. A third edition (with I. Hubeny) which describes modern fast, iterative methods to solve the transfer equation, including realistic line-blanketing, is in press.
In the period 1981 – 1998, as a consultant to LANL, Dimitri gave lectures on radiation hydrodynamics, for which, he received a number of “Certificate of Appreciation” by X-Division for “Outstanding Service to the Applied Theoretical Division”. In 1984 Dimitri completed the above-mentioned Foundations of Radiation Hydrodynamics. In 1999 Dover Publications reprinted it in inexpensive paperbound form at the urging of many scientists from LANL, LLNL, NRL, and the academic community.
In the period 1987 – 1994 Dimitri worked with Anderson, Hummer, and B. Mihalas on the development of a modern EOS code for stellar envelopes, in support of the large British – American Opacity Project (OP) led by Professor M. J. Seaton. It emerged that the OP results are in excellent agreement (better than 10%) with the independent LLNL OPAL computations. These new opacity data significantly impact stellar evolution calculations, and have helped resolve several previous discrepancies between calculation and observation, especially with the interpretation of Cepheid variable pulsations.
Jointly with Stone, Dimitri showed that the computational oscillations or diffusion, typically found in numerical simulations of a propagating radiation front in vacuum, could be eliminated by using upwind monotonic interpolation methods. They (and M. Norman) also collaborated on incorporating 2-D radiative transfer in the radiation magnetohydrodynamics code ZEUS 2-D developed at the University of Illinois and extensively used by astrophysicists.
In collaboration with K.-H. Winkler and M. Norman, Dimitri developed novel implicit adaptive grid methods to solve 1-D radiation hydrodynamics problems having multiple time and space scales ranging over many orders of magnitude. Dimitri derived the “adaptive-grid transport theorem” rigorously. In 1994 – 1997, Dimitri developed TITAN, a 1-D implicit adaptive-grid code. In collaboration with Cheng at Los Alamos, Dimitri used TITAN to compute the best-ever numerical solution of the infamous Noh stagnating shock problem in planar, cylindrical, and spherical geometry. In 1999, in collaboration with Gehmeyr, and Sincell, Dimitri studied the famous Zeldovich and Heaslet/Baldwin supercritical shock problem and was able to compute the first numerical solutions for this problem. Also in the same year, Dimitri and Auer wrote “An X-6 Radiation Hydrodynamics Primer” intended for LANL use, and in 2001 they published an incisive discussion on exact relativistic laboratory-frame radiation hydrodynamics.
Dimitri was honored for his many scientific contributions at the International Conference in Honor of Dimitri Mihalas for his Lifetime Scientific Contributions on the Occasion of his 70th Birthday held in Boulder, CO in late March 2009.
In addition to his many scientific contributions, he also published several collections of his poetry and other writings. These other writings include "A Primer on Depression and Bipolar Disorder" and "Depression, Bipolar Disorder, and Spiritual Growth." These books have had as profound an impact as his professional textbooks and articles.
Throughout his long career, Dimitri gave generously of himself to all with whom he interacted. As an advisor, role model, confidant, and friend, he saw each person as an individual, acknowledging strengths, helping overcome weaknesses, giving encouragement, and enthusiastically praising their success. He touched the lives and careers of many students and colleagues and has left a lasting legacy to be cherished by those who knew him.
Reprinted with permission from Physics Today.
Baolian Cheng, LANL, Los Alamos, NM John Castor, LLNL, Livermore, CA
Jim Stone, Princeton University, Princeton, NJ
Dr. Andreas -Andy- Gerasimos Michalitsianos (Greek: Ανδρέας Γεράσιμος Μιχαλιτσιάνος) (May 22, 1947 – October 29, 1997) was a Greek-American astronomer and a NASA astrophysicist, also known and published as Andrew G. Michalitsianos.
Born in Alexandria, Egypt on May 22, 1947, Andreas grew up with his mother, who spoke little English and briefly, with his father. He moved with his family to New York City in 1949 and lived in the Queens borough before going to college. Michalitsianos father, Gerasimos Andreas, was a sea captain of a Greek tanker, the SS Foundation Star (formerly SS Lampas), but the ship was caught up in a hurricane and sunk in September 1952 off the coast of Norfolk, Virginia and Michalitsianos father died of pneumonia shortly after rescue. Andreas showed an early interest in astronomy and physics from an early age, winning a science contest in 1959 and serving as president of the Junior Astronomy Club in NYC where his accomplishments included leading a South American eclipse expedition. He graduated from Newtown High School in 1965 and then earned his bachelors degree in physics from the University of Arizona at Tucson in 1969, working at the nearby Kitt Peak National Observatory as a student employee in the Space Division to help pay off his college debts. His duties at Kitt Peak included the initial tests of a remotely controlled telescope.
Andreas then received a scholarship and earned his Ph.D. in astrophysics from University of Cambridge, Churchill College in 1976 while doing research on a theoretical topic in solar physics. He would later work as a junior research fellow at the California Institute of Technology and then as an astrophysicist at NASAs Goddard Space Flight Center from the 1970s until his death. Michalitsianos was involved with such projects as the Hubble Space Telescope and was the Deputy Project Manager of the Observatory Branch for Goddards highly successful International Ultraviolet Explorer, in which he won several awards for his contributions. Michalitsianos eventually went on to become Chief of the Laboratory for Astronomy and Solar Physics at the Goddard Space Flight Center in early 1997, and was renowned for his breakthrough research on symbiotic stars. His many awards included the NASA Meritorious Achievement Award.
Michalitsianos died on October 29, 1997 in Baltimore, Maryland after a long struggle with a brain tumor. Until his last days he was hard at work rejuvenating the Laboratory of which he had recently taken command, and on a proposal for a spacecraft to monitor temporal changes in the ultraviolet and X-ray spectra of stars and active galaxies. He is survived by a wife, two daughters, a sister, and one son.
A landbased robotic telescope on the island of Cefalonia in western Greece is named in his honor. The Andreas Gerasimos Michalitsianos telescope, located within a former Hellenic Air Force communications station, has been utilized by Greek universities and The Eudoxos Project to advance Greek secondary education in introductory astronomy and physics laboratories for high school students.
Matthaios Michalodimitrakis was born in Florina in 1943 and graduated from the Department of Physics of the University of Thessaloniki in 1967. In 1968 he was appointed assistant in the A’ Laboratory of Physics and in 1969 he moved to the Theoretical Mechanics Studiorum. In 1970 he obtained his Master degree in Electronic Physics and in 1974 he completed his PhD thesis. In 1975 he was hired as chief assistant at the Department of Physics becoming a Docent in 1980. In 1982 he was appointed as an Assistant Professor and in 1983 he was promoted to Associate Professor. He died in a car accident on May 31, 1990.
Prof. Michalodimitrakis published 32 papers in refereed scientific journals, mainly on the computation of periodic orbits in the 3- and 4-body problems, in the Hill’s problem and in various galactic models. He supervised two PhD students. He wrote a book on Special Relativity and two books on the methodology of problem solving in Newtonian and Analytical Dynamics.