IMPORTANT SCIENTIFIC RESULTS OBTAINED AT BAO

The main achievements of the Armenian astronomy are connected with V.A. Ambartsumian and development of his ideas and projects in Byurakan starting with the very first years of its foundation. Ambartsumian ideas put the basis of new views on origin and evolution of cosmic objects and new approaches in observational and theoretical investigations resulting in many important discoveries during a few decades. Following Ambartsumian’s ideas, another prominent Armenian astronomer, B.E. Markarian, conducted and accomplished the famous Byurakan Surveys, the most important observational works made in the Byurakan Observatory, and several other projects were undertaken based on them. This is the first attempt to list the most important results obtained in Byurakan and/or by Byurakan astronomers in collaboration with foreign colleagues. Any comments and complements are welcome.  

 

The most important scientific results have been selected and are listed according to criteria that they must be one of the following:

 

·         Suggestion of fundamental ideas (ex. Ambartsumian’s idea on the activity of galactic nuclei)

·         Development of new theories and models (ex. Gurzadyan’s theory of the structure of planetary nebulae)

·         Solution of important theoretical problems (ex. Ambartsumian’s solution of the problem of the reflection of monochromatic radiation from one-dimensional medium)

·         Suggestion of new methods (in theoretical or observational studies) (ex. Ambartsumian’s method for estimation of the total number of flare stars in a stellar system)

·         Explanation of some astrophysical phenomena or processes (ex. Mirzoyan’s explanation of strong flares as superposition of several weak flares)

·         Observational discoveries (ex. Ambartsumian’s discovery of stellar associations; discoveries of new objects in frame of large projects)

·         Large observational projects (ex. Markarian’s First and Second Byurakan Surveys; observations of flare stars in stellar aggregates)

·         Observational proof of a theory or hypothesis (ex. Markarian’s proof of expansion of stellar associations; Arakelian’s proof of the extragalactic nature of QSOs)

·         Suggestion of new classifications (ex. Khachikian’s classification of Seyfert galaxies; Oskanian’s classification of light-curves of flares)

·         Compilation and publication of catalogs and atlases (ex. Arakelian’s catalog of high-surface-brightness galaxies; Parsamian’s catalogs of cometary nebulae)

·         Creation or building of new instruments and databases (ex. Gurzadyan’s “Orion” and Tovmassian’s “Glazar” space observatories)

 

 

1947                 Discovery of stellar associations, groups of hot (OB) giants and T Tauri stars. It was shown for the first time that the star formation process continues at all stages of the evolution of our Galaxy, including the present one and that the star formation is a permanent process (the maximum ages of stellar associations were estimated at 10⁷ yr compared to 10¹⁰ yr of the age of the Galaxy). A conclusion was drawn that stars are formed not individually, but in groups (V.A. Ambartsumian).

 

V.A. Ambartsumian, Evolution of Stars and Astrophysics // Acad. Sci. ArmSSR), 39 p., Yerevan, 1948 (in Armenian).

V.A. Ambartsumian, Preliminary Data on O-Associations in the Galaxy // Doklady USSR Acad. Sci., Vol. 68, No. 1, p. 21-22, 1949 (in Russian).

 

1949-1951         Theoretical prediction of the phenomenon of expansion of stellar associations. Revealing the importance of the stellar associations as dynamically unstable entities. Statistics of the Trapezium Orionis type systems and a proof of disintegration of the young stellar systems based on measurements of the proper motions of stars (V.A. Ambartsumian, B.E. Markarian).

 

V.A. Ambartsumian, Stellar Associations // Astron. Zh., Vol. 26, No. 1, p. 3-9, 1949 (in Russian).

V.A. Ambartsumian, B.E. Markarian, Stellar Association around P Cygni // Communications of the Byurakan Observatory, No. 2, p. 3-17, 1949 (in Russian).

V.A. Ambartsumian, On the Frequency of the Orion Trapezium type Apparent Multiple Systems // DAS ArmSSR, Vol. 13, No. 4, p. 97-103, 1951 (in Russian).

V.A. Ambartsumian, On the Statistics of Trapezium type Multiple Systems // Doklady Acad. Sci. ArmSSR, Vol. 13, No. 5, p. 129-131, 1951 (in Russian).

 

1954                 Prove of the nonthermal nature of the continuous emission observed in the spectra of non-stable stars and putting forward an idea about new possible sources of stellar energy, the hypothesis of the superdense protostellar matter (V.A. Ambartsumian).

 

V.A. Ambartsumian, The Phenomenon of the Continuous Emission and Sources of Stellar Energy) // Comm. BAO, No. 13, p. 1-36, 1954 (in Russian).

 

1956                 Statistical proof that radiogalaxies could not happen due to collisions of two galaxies (V.A. Ambartsumian).

 

1956                 The hypothesis on the activity of galactic nuclei. The various forms of activity were presented as different manifestations of the same phenomenon of activity. The evolutionary significance of the activity in the galactic nuclei was emphasized and a further hypothesis was suggested on the ejection of new galaxies from the active galactic nuclei. The hypothesis on the superdense protostellar matter was engaged to explain the observational data (V.A. Ambartsumian).

 

V.A. Ambartsumian, On the Nature of Radio Sources) // Proc. Fifth conf. on Problems of Cosmogony: "Radioastronomy", held on 9-12 Mar 1955. Acad. Sci. USSR), p. 413-416, Moscow, 1956 (in Russian).

V.A. Ambartsumian, On Multiple Galaxies // Izvestiya Acad. Sci. ArmSSR, Ser. Phys.-Math., Nat. and Tech. Sci., Vol. 9, No. 1, p. 23-43, 1956 (in Russian).

 

1957-1958         Discovery of blue outbursts and companions near elliptical galaxies supporting Ambartsumian’s hypothesis of activity of galactic nuclei (V.A. Ambartsumian, R.K. Shahbazian).

 

V.A. Ambartsumian, R.K. Shahbazian, Multiple Galaxies and Radiogalaxies. Report II. Blue Outbursts and Companions of Elliptical Galaxies // Doklady Acad. Sci. ArmSSR, 25, 4, p. 185-192, 1957 (in Russian).

V.A. Ambartsumian, R.K. Shahbazian, Multiple Galaxies and Radiogalaxies. Report IV. Blue Objects near the Elliptical Galaxies // Doklady Acad. Sci. ArmSSR, Vol. 26, No. 5, p. 277-279, 1958 (in Russian).

 

1960-1961         Theoretical studies of the hypothetical superdense degenerate protostellar matter: development of principles of the theory of baryonic stars, which allowed a detailed research of physical conditions in superdense stellar conditions in the frame enabled by the modern knowledge of physics. These researches later on allowed increasing the Chandrasekhar limit of stellar masses (V.A. Ambartsumian, in collaboration with G.S. Saakyan, Yerevan State University).

 

V.A. Ambartsumian, G.S. Saakyan, The Degenerate Superdense Gas of Elementary Particles // Soviet Astronomy, Vol. 4, No. 2, p. 187-201, 1960.

V.A. Ambartsumian, G.S. Saakyan, On Equilibrium Configurations of Superdense Degenerate Gas Masses // Soviet Astronomy, Vol. 5, No. 5, p. 601-610, 1962.

V.A. Ambartsumian, G.S. Saakyan, Internal Structure of Hyperon Configurations of Stellar Masses // Soviet Astronomy, Vol. 5, No. 6, p. 779-784, 1962.

 

1963                 Discovery of superassociations in distant galaxies, large blue formations, later found to be emission-line objects and called HII regions. A proof of young age of these galaxies (V.A. Ambartsumian, S.G. Iskudarian, R.K. Shahbazyan, K.A. Sahakian).

 

                        V.A. Ambartsumian, S.G. Iskudaryan, R.K. Shahbazyan, K.A. Saakyan, Superassociations in Distant Galaxies // Comm. BAO, Vol. 33, p. 3-18, 1963 (in Russian).

 

1964                 Application of the principle of invariance to the solutions of non-linear problems of the radiation transfer theory; solution of the problem of the reflection of monochromatic radiation from one-dimensional medium. Formulation of a new method; the principle of self-consistent optical depths for the study of non-linear scattering processes (V.A. Ambartsumian).

 

1965                 Estimation of the frequency of supernovae in supergiant galaxies as one in 20-30 years (V.A. Ambartsumian).

 

V.A. Ambartsumian, Comments on the question of the frequency of supernovae // Astrophysics, Vol. 1, No. 4, p. 248, 1965.

 

1968                 Statistical studies of the flare stars revealed their evolutionary status: a method for estimation of the total number of flare stars in a star system based on the number of the observed flares. The flare activity was shown to be the regular stage in the evolutionary path of the low luminosity and low mass late-type stars. It was proved that all the stars of the mentioned category necessarily pass through the stage of flare activity in the early phases of their evolution (V.A. Ambartsumian).

 

V.A. Ambartsumian, On the Statistics of Flare Objects // Proc. symp. "Stars, Nebulae, Galaxies", devoted to the 60th anniversary of academician V.A. Ambartsumian, held in Byurakan, 16-19 Sep 1968. Acad. Sci. ArmSSR, p. 283-292, Yerevan, 1969 (in Russian).

 

1971                 Explanation of the change of brightness of FU Ori star by the expansion of its gaseous envelope. Introducing the class of Fuors (V.A. Ambartsumian).

 

                                V.A. Ambarstumian, Fuors // Astrophyiscs, Vol. 7, No. 4, p. 331-339, 1971.

 

1964-1970s       The Byurakan classification of central regions of spiral galaxies based on the study of the central regions of more than 700 objects; revealing galaxies with star-like and split nuclei, possible AGN (V.A. Ambartsumian, A.T. Kalloghlian, H.M. Tovmassian, K.A. Sahakian, S.G. Iskudarian, E.S. Parsamian).

 

                                A.T. Kalloghlian, H.M. Tovmassian // Commun. BAO, Vol. 36, p. 31, 1964.

                                H.M. Tovmassian // Astrofizika, Vol. 1, p. 197, 1965.

H.M. Tovmassian // Astrofizika, Vol. 2, p. 317, 1966.

K.A. Sahakian // Astrofizika, Vol. 4, p. 41, 1968.

E.S. Parsamian // Astrofizika, Vol. 4, p. 150, 1968.

S.G. Iskudarian // Astrofizika, Vol. 4, p. 385, 1968.

 

1978                 The original solution of the inverse problem of derivation of the distribution function of average frequencies of flares in the given stellar system on the basis of the chronology of discovery (first flares) and the chronology of confirmation (the temporal distributions of repeated flares) of the flare stars (V.A. Ambartsumian).

 

V.A. Ambartsumian, Derivation of the frequency function of stellar flares in a star cluster // English translation in: Astrophysics, Vol. 14, No. 3, p. 209-217, 1978.

 

1978-1979         Study of the UV spectrum of the peculiar star P Cyg; detection of largely expanded photosphere. It was shown that the acceleration of the outflow of matter from this star begins in the deep layers of its photosphere (V.A. Ambartsumian, L.V. Mirzoyan, in collaboration with T.P. Snow, USA).

 

                                V.A. Ambartsumian, L.V. Mirzoyan, T.P. Snow, P Cygni in the Far Ultraviolet // Astrofizika, Vol. 14, No. 3, p. 425-438, 1978.

                                V.A. Ambartsumian, L.V. Mirzoyan, T.P. Snow, Ultraviolet observations of P Cygni with Copernicus // Astrophys. J., Vol. 227, No. 1, p. 519-525, 1979.

 

 

 

1952                 Compilation and publication of the Atlas of stellar clusters of various types (B.E. Markarian).

 

B.E. Markarian, Atlas of Stellar Clusters of Various Types // Publication of the Astronomical Council, Moscow, 1952 (in Russian).

 

1958-1966         Detailed photometric and colorimetric investigations of nearby galaxies and galaxies in the Virgo cluster for determination of the distribution of colors and hence the different stellar populations in them (B.E. Markarian, A.T. Kalloghlian, E.S. Hovhannessian, S.N. Arakelian).

 

1963                 Selection of galaxies with anomalous spectral features for their type. Explanation of the excessive UV as non-thermal radiation. Understanding the principles for search for new active galaxies and conduction of the First Byurakan Survey (B.E. Markarian).

 

B.E. Markarian, On the Nature of Galaxies Having Anomalous Spectral Features for their Type // Communications of BAO, No. 34, p. 3-18, 1963 (in Russian).

 

1965-1980         The First Byurakan Survey (FBS), the first systematic and the largest objective prism spectroscopic survey (17,000 sq. deg.). 1500 UV-excess galaxies were revealed (Markarian galaxies). Many new AGN and Starburst galaxies were found.(B.E. Markarian, V.A. Lipovetski, J.A. Stepanian).

 

B.E. Markarian, Galaxies with an Ultraviolet Continuum // Astrophysics, Vol. 3, p. 55-68, 1967.

B.E. Markarian, V.A. Lipovetski, J.A. Stepanian, L.K. Erastova, A.I. Shapovalova, Catalogue of Markarian Galaxies // Communications of SAO, Vol. 62, p. 1-117, 1989. VizieR On-line Data Catalog: VII/172.

 

1978-1991         The Second Byurakan Survey (SBS), a deeper and higher resolution large area (965 sq. deg.) sky survey for UV-excess and emission-line galaxies and QSOs, and blue stars. Objects filling the gap between Local Universe AGNs and distant QSOs were revealed (B.E. Markarian, J.A. Stepanian, L.K. Erastova, V.A. Lipovetski, V.H. Chavushian, et al.).

 

B.E. Markarian, V.A. Lipovetski, J.A. Stepanian, The Second Byurakan Spectral Sky Survey. I. Quasistellar and Seyfert Objects // Astrophysics, Vol. 19, p. 29-43, 1983.

J.A. Stepanian, The Second Byurakan Survey. General Catalogue // Revista Mexicana de Astronomia y Astrofisica, Vol. 41, p. 155-368, 2005.

 

1980-1988         Spectroscopic studies of the First Byurakan Survey galaxies – galaxies with UV continuum. Discovery of many new Seyfert galaxies and other AGN (B.E. Markarian, V.A. Lipovetski, J.A. Stepanian, L.K. Erastova).

 

B.E. Markarian, L.K. Erastova, J.A. Stepanian, V.A. Lipovetski, A.I. Shapovalova, Spectra of Galaxies with UV-Continuum. VII // Astrofizika, Vol. 28, p. 476-486, 1988 (and references therein).

 

1980-1999         Spectroscopic studies of the SBS stellar objects; discovery of hundreds of new QSOs, white dwarfs, hot subdwarfs, HBB stars, cataclysmic variables, planetary nebulae, etc (B.E. Markarian, J.A. Stepanian, V.A. Lipovetski, L.K. Erastova, V.H. Chavushian, in collaboration with astronomers from Mexico).

 

J.A. Stepanian, V.H. Chavushyan, L. Carrasco, H.M. Tovmassian, L.K. Erastova, Spectroscopy of Stellar-like Objects Contained in the Second Byurakan Survey. I // Publ. Astron. Soc. Pacific, Vol. 111, No. 763, p. 1099-1114, 1999 (and references therein).

 

1960s               The theory of double shell structure of planetary nebulae based on the dynamics of these objects (G.A. Gurzadyan).

 

1965                 A new model for explanation of the flare activity of flare stars. It was considered as a result of Compton scattering of the photons of the thermal radiation on the fast (but non-relativistic) electrons (G.A. Gurzadyan).

 

1966                 Observation of a powerful flare on the Sun (of October 1, 1965) using ballistic rockets R-5. One of the earliest papers on space astronomy (G.A. Gurzadyan).

 

G.A. Gurzadyan, A Powerful X-ray Flare on the Sun // Comm. Armenian Acad. Sciences, Vol. XLIII, p. 28, 1966.

 

1971                 Designing and building of the first Soviet ultraviolet space observatory, Orion-1 that operated onboard Soviet spacecraft Salyut-1 in April 1971. the It was the first space telescope with an objective prism. Obtaining slitless UV spectra of a few stars (G.A. Gurzadyan).

 

1973                 Designing and building of the second Soviet ultraviolet space observatory, Orion-2 that operated onboard Soviet spacecraft Soyuz-13 in December 1973. Obtaining objective prism UV spectra for 800 stars to as faint as 13^th magnitude (G.A. Gurzadyan).

 

 

 

1950s               Confirmation of the expansion of stellar association based on study of radial velocities of the stars, members of associations. An independent estimation of the age of O-B5 type stars (L.V. Mirzoyan).

 

1950s               Spectral investigation of hot stars in stellar associations (L.V. Mirzoyan, et al.).

 

1950s               Statistical study of Wolf-Rayet stars proving that almost all very hot Wolf-Rayet stars should be binaries and their components, as well as all other members of stellar associations have common origin (L.V. Mirzoyan).

 

1950s               Suggestion of a new method for measuring of the interstellar selective absorption (L.V. Mirzoyan).

 

1950s               Creation of the method of “synthetic” stellar association and prove of the expansion of OB-associations (L.V. Mirzoyan).

 

1968-1982         Spectrophotometric study of unusual objects V1057 Cyg, FG Sge, RW Aur, and SS Cyg (L.V. Mirzoyan, in collaboration with D.Chalonge and L.Divan, France).

 

L.V. Mirzoyan, D.Chalonge, L.Divan, Spectrophotometric studies of non-stable stars, I-IV, series of papers in Astrophysics, 1968-1982.

 

1970s               It was shown that strong flares could be explained by superposition of several weaker flares (L.V. Mirzoyan).

 

1980s               Study of the spatial distribution of flare stars in Pleiades; it was shown that the mean frequency of flares increases with the distance from the centre of the cluster (L.V. Mirzoyan, M.A. Mnatsakanian, et al.).

 

1988-1989         Statistical studies of flare stars; on the basis of the observational data (flare light curves, spectra in minimum, luminosities, flare duration, mean flare frequency, energy spectra, colours of flare emission, Hertzsprung-Russell diagrams, flare-ups in radio and X-ray) it was shown that there exists similarity between the UV Ceti stars of the solar vicinity and the flare stars in clusters and associations. The differences between these stars were explained by the differences in their ages (L.V. Mirzoyan, V.V. Ambaryan, A.T. Gharibjanian, A.L. Mirzoyan).

 

                                L.V. Mirzoyan, V.V. Ambaryan, A.T. Garibdzhanyan, A.L. Mirzoyan, Statistical investigation of flare stars. IV. Relative number of flare stars in the Orion association, the Pleiades, and the neighborhood of the Sun // Astrophysics, Vol. 31, No. 2, p. 567-574, 1989 (and references therein).

 

1990-1997         Spectroscopic studies of red dwarfs; flare stars in the Pleiades cluster and Solar neighbourhood.(L.V. Mirzoyan, V.V. Hambaryan, A.T. Gharibjanian).

 

                                L.V. Mirzoyan, V.V. Hambarian, A.T. Garibjanian, Spectroscopic observations of red dwarfs. III. Observations of red stars in the solar neighborhood // Astrophysics, Vol. 40, No. 2, p. 125-130, 1997 (and references therein).

 

 

 

1960s-1970s     Measurements of radial velocities of 800 faint galaxies and quasars (M.A. Arakelian, in collaboration with astronomers of the Sternberg Astronomical Institute, Russia).

 

1968-1969         Study of the luminosity evolution of QSOs based on the evolutionary effects associated with them (M.A. Arakelian).

 

M.A. Arakelyan, Evolutionary effects associated with quasi-stellar radio sources. I // Astrophysics, Vol. 5, No. 3, p. 226-236, 1969.

                                M.A. Arakelyan, Nature of evolutionary effects connected with quasi-stellar radio sources. II // Astrophysics, Vol. 5, No. 4, p. 308-317, 1969.

                                M.A. Arakelyan, Evolution of the luminosity of quasars // Astron. Tsirk., No. 552, p. 1-3, 1970.

M.A. Arakelian, Evidence of Radio Luminosity Evolution of Quasi-stellar Radio Sources // Nature, Vol. 225, No. 5230, p. 358-359, 1970.

 

1970                 Derivation of the luminosity function of field galaxies (M.A. Arakelian, A.T. Kalloghlian).

 

M.A. Arakelyan, A.T. Kalloglyan, The Luminosity Function of Field Galaxies // Soviet Astronomy, Vol. 13, p. 953, 1970.

 

1970-1971         The proof of the extragalactic origin of QSOs (M.A. Arakelian).

 

M.A. Arakelyan, The spatial distribution and luminosity function for quasistellar radio sources // Astrophysics, Vol. 6, No. 4, p. 291-296, 1970.

M.A. Arakelyan, On the distances of quasi-stellar radio sources // Vestn. Akad. Nauk SSSR, No. 11, p. 26-30, 1971.

 

1970-1973         Spectroscopic observations and studies of a few hundred Markarian galaxies and discovery of more than 40 new Seyfert galaxies among them (M.A. Arakelian, in collaboration with E.A. Dibai and V.F. Esipov).

 

M.A. Arakelyan, E.A. Dibai, V.F. Esipov, Spectra of Markaryan galaxies. VIII // Astrophysics, Vol. 9, No. 3, p. 183-186, 1973 (and references therein).

 

1972-1974         Analysis of the surface brightness of emission-line galaxies (including Seyfert and Markarian ones) and revealing galaxies with high surface brightness (named Arakelian galaxies), a new source containing many AGN (M.A. Arakelian).

 

M.A. Arakelyan, Relationship between the gradient of the surface brightness and other characteristics of Seyfert galaxies // Astrophysics, Vol. 8, No. 4, p. 368-369, 1972.

M.A. Arakelyan, Estimates of the Surface Brightness of Selected Markarian Galaxies. I // Astrofizika, Vol. 8, p. 473, 1972.

M.A. Arakelyan, Surface brightness of galaxies with emission lines // Astrophysics, Vol. 10, No. 4, p. 321-326, 1974.

 

1973                 Suggestion of a new method for definition of space density of extragalactic objects and estimation of the mean density of matter in the Metagalaxy (M.A. Arakelian).

 

M.A. Arakelyan, Estimate of the mean density of matter in the Metagalaxy // Astrophysics, Vol. 9, No. 1, p. 84-85, 1973.

 

1975                 Compilation and publication of the "Catalogue of high surface brightness galaxies" (named Arakelian galaxies) containing 621 objects with surface brightness at least 22.0 magnitudes from an area of 1 sq. arcsec. 4% of all the galaxies in an area of 4.5 sr at d>-3° and |b|>20° were listed, including 30 Markarian, 29 Zwicky, and 7 blue Haro galaxies. Morphological description and colors were given (M.A. Arakelian).

 

M.A. Arakelyan, Galaxies of high surface brightness // Commun, BAO, No. 47, p. 3-42, 1975 (in Russian).

 

1975                 Classification of the central regions of 711 galaxies (M.A. Arakelian).

 

M.A. Arakelyan, Classification of the Central Regions of 711 Galaxies // Comm. BAO, Vol. 47, p. 43, 1975 (in Russian).

 

1975                 Derivations of the luminosity function and space density of galaxies with UV continuum (Markarian galaxies) (M.A. Arakelian).

 

M.A. Arakelyan, Luminosity function and space density of galaxies with an ultraviolet continuum // Soviet Astronomy, Vol. 18, p. 432, 1975.

 

1975-1976         Spectroscopic observations and studies of Arakelian galaxies (galaxies with high surface brightness) (M.A. Arakelian, in collaboration with E.A. Dibai and V.F. Esipov).

 

M.A. Arakelyan, E.A. Dibai, V.F. Esipov, Spectral observations of high-surface-brightness galaxies. IV // Astrophysics, Vol. 12, No. 4, p. 456-458, 1976 (and references therein).

 

1976-1977         Study of the dependence of the emission-line intensities of Markarian and Seyfert galaxies on their color index (M.A. Arakelian).

 

M.A. Arakelyan, Dependence of the emission-line intensity of Markaryan galaxies on color index // Astrophysics, Vol. 12, No. 3, p. 366-368, 1976.

M.A. Arakelyan, Dependence of the emission line intensitites of Seyfert galaxies on the color index // Astrophysics, Vol. 13, No. 3, p. 241-246, 1977.

 

1977                 Study of the distribution of the mean surface brightness of galaxies in the Coma cluster (M.A. Arakelian).

 

M.A. Arakelyan, Distribution of the mean surface brightnesses of galaxies in the Coma cluster // Astrophysics, Vol. 13, No. 4, p. 386-388, 1977.

 

1977-1980         Study of the relation between the mean surface brightness and radio emission of galaxies, including Seyfert galaxies (M.A. Arakelian, R.A. Kandalyan).

 

M.A. Arakelyan, Mean surface brightnesses and radio emission of galaxies // Astrophysics, Vol. 13, No. 2, p. 130-134, 1977.

M.A. Arakelyan, R.A. Kandalian, Mean surface brightnesses and radio emission of Seyfert galaxies // Astrophysics, Vol. 16, No. 4, p. 383-386, 1980.

 

1981                 Study of the estimations of the kinetic energies of clusters of galaxies; the extent to which a kinetic energy estimate would be affected by a possible mass dependence of the velocity dispersion of galaxies in clusters is considered. For the case of a negative correlation between velocity dispersion and mass, the kinetic energy may in practice be underestimated due to the velocity dispersion obtained from galaxies of the highest mass luminosity (M.A. Arakelian, in collaboration with A.G. Kritsuk).

 

M.A. Arakelian, A.G. Kritsuk, On estimating the kinetic energies of clusters of galaxies // Astrophysics, Vol. 17, No. 4, p. 384-389, 1981.

 

1981                 Radio measurements and publications of the accurate optical positions of Arakelian galaxies (M.A. Arakelian, in collaboration with astronomers from USA).

 

G. Kojoian, R. Elliott, M.D. Bicay, M.A. Arakelian, Accurate Optical Positions of Arakelian Galaxies // Astron. J., Vol. 86, p. 820, 1981.

 

1981-1982         Study of the surface brightness of isolated and double galaxies (M.A. Arakelian, A.P. Mahtessian).

 

M.A. Arakelian, A.P. Magtesian, Mean surface brightness of isolated and double galaxies // Astrophysics, Vol. 17, No. 1, p. 28-32, 1981.

M.A. Arakelian, A.P. Magtesian, Spectrophotometry of four galaxies of high surface brightness // Soviet Astronomy Letters, Vol. 8, p. 181-183, 1982 (and references therein).

 

1983                 Proposing a method for constructing the luminosity function of the components of double galaxies on the basis of an arbitrary sample of pairs of galaxies. The results are applied to the data of Karachentsev's Catalog of Isolated Pairs (1972). The obtained luminosity function of the components of the pairs was almost identical to the luminosity function of randomly chosen field galaxies. The presence of a correlation between the absolute magnitudes of the components of pairs is confirmed (M.A. Arakelian).

 

M.A. Arakelyan, Distribution of apparent magnitudes and luminosities of double galaxies // Astrophysics, Vol. 19, No. 4, p. 379-385, 1983

 

1986                 A method for the determination of the bivariate luminosity function utilizing an incomplete sample with an application to Seyfert galaxies. It was shown that the results of incomplete radio and X-ray surveys could be used for the determination of the bivariate luminosity functions, having both the distribution of luminosities of objects in the detected subsample and the distribution of apparent magnitudes in the surveyed sample (M.A. Arakelian).

 

M.A. Arakelyan, A proposed method for the determination of the bivariate luminosity function utilizing an incomplete sample with an application to Seyfert galaxies // Astrophys. J., Part 1, Vol. 301, p. 92-97, 1986.

 

 

 

1960s-1970s     Radio observations of more than 1000 Markarian galaxies on radio telescopes of the USA and FRG. Discovery of radio emission from Seyferts and BL Lac objects among them. Revealing differences of radio emission between Sy1 and Sy2 galaxies (H.M. Tovmassian).

 

1970s               Radio observations of a few hundred clusters of galaxies and a consequent identification of detected radio sources with individual galaxies. It was shown that radio sources occur mainly in clusters of Bauts-Morgan type I, clusters having only one very bright galaxy (H.M. Tovmassian).

 

1970s               By means of radio continuum (HII) and monochromatic (H I) observations of about 20 young stellar clusters it was shown that around some of them exist expanding gas clouds (H.M. Tovmassian).

 

197?-198?        Discovery of supershort (spiky) flares of duration of a few tenths of a second by observations with specially constructed two-color fast photometer. It was shown that spiky flares usually appear on the declining part or after the usual flares of duration of a few minutes, and that they usually are bluer. It was shown that the multiplicity of forms of stellar flares depend on the position of flare on the star's disc (H.M. Tovmassian, V.P. Zalinian, et al.).

 

1980s               Study of the IR radiation of more than 100 late-type giant stars with anomalous chemical composition (excessive abundance of C, Zr, La, etc.); discovery of IR excess for many of them proving the presence of dust shells (H.M. Tovmassian, Yu.K. Melik-Alaverdian, et al.).

 

1980s               Study of the UV spectra of galaxies by means of the Soviet space observatory Astron; significant increase of radiation at far UV was detected for some galaxies (H.M. Tovmassian, et al.).

 

1987                 Designing and building of the space observatory “Glazar” (40 cm telescope, 1.3 degree field of view), which operated onboard Soviet space station “Mir”. About 20 O-type stellar associations were observed at 1640 A. Due to larger influence of extinction at 1640 A, a number of new O-associations were detected in directions of known associations (H.M. Tovmassian, et al.).

 

H.M. Tovmassian, Y.M. Khodzhayants, M.N. Krmoyan, et al., The Glazar Orbiting Ultraviolet Telescope // Astron Letters, Vol. 14, No. 2, p. 123, 1988.

 

1990-1996         Study of OB Stellar Associations with the Glazar UV space observatory at 1640 A wavelength; O-B-A type stars were observed in the direction of 20 associations, 93 stars with dust envelopes were found, half of them also being IR sources (H.M. Tovmassian, R.Kh. Hovhannessian, R.A. Epremian in collaboration with astronomers from Switzerland).

 

H.M. Tovmassian, S.G. Navarro, O. Cardona, R.Kh. Hovhannessian, R.A. Epremian, OB Stellar Associations in Crux. I. Observations with the Glazar Space Telescope // Astron. J., Vol. 111, p. 299, 1996.

H.M. Tovmassian, S.G. Navarro, O. Cardona, OB Stellar Associations in Crux. II. Analysis and Discussion // Astron. J., Vol. 111, p. 306, 1996 (and references therein).

 

 

 

1954                 Discovery of the polarization of radiation of the Crab nebula (by means of electrophotometric observations), remnant of the 1054 supernovae, and confirmation of the synchrotron nature of its radiation (V.A. Dombrovski, Leningrad State University).

 

195?-1967         Study of distribution of the polarized radiation over the Crab nebula and revealing its variability based on photographic observations; up to 50% polarization at some regions was found (E.Ye. Khachikian, J.A. Einatian).

 

E.E. Khachikyan, Dzh.A. Einatyan, Variability of polarization of the Crab Nebula // Astrophysics, Vol. 3, No. 4, p. 262-263, 1967 (and references therein).

 

1968-1969         First spectroscopic observations of Markarian galaxies; discovery of new Seyfert galaxies among them (E.Ye. Khachikian, in collaboration with D.W. Weedman, Cornell University, USA).

 

D.W. Weedman, E.E. Khachikyan, Spectral observations of Markaryan galaxies with ultraviolet continuum: I // Astrophysics, Vol. 4, No. 4, p. 243-251, 1968.

D.W. Weedman, E.E. Khachikyan, Spectral observations of Markaryan galaxies with ultraviolet continuum. II // Astrophysics, Vol. 5, No. 1, p. 51-59, 1969.

 

1971                 Spectral classification of Seyfert galaxies into Sy1 and Sy2 types (E.Ye. Khachikian, in collaboration with D.W. Weedman, Cornell University, USA).

 

E.Ye. Khachikyan, D.W. Weedman, A spectroscopic study of luminous galactic nuclei // Astrophysics, Vol. 7, No. 3, p. 231-240, 1971.

 

1974                 Compilation and publication of an Atlas of Seyfert galaxies; data available for 71 Seyfert galaxies were summarized. A collection of 37 spectra was presented, and new UBV data were given for 18 galaxies. A well-defined angular-diameter-redshift relation was found to exist for the total sample; it was concluded that the redshifts are cosmological. The mean UV magnitude for 40 Seyfert nuclei resembling QSOs was calculated to be -20.4 (E.Ye. Khachikian, in collaboration with D.W. Weedman, Cornell University, USA).

 

E.Y. Khachikian, D.W. Weedman, An atlas of Seyfert galaxies // Astrophys. J., Vol. 192, No. 1, p. 581-589, 1974.

 

1974-1988         Spectroscopic investigation of peculiar irregular M82 type galaxies (N.K. Andreassian, E.Ye. Khachikian, in collaboration with astronomers from USA).

 

1974-1988         Spectrophotometric study of galaxies with UV excess (Kazarian galaxies). The spectra of galaxies were obtained with the 6m SAO telescope. Redshifts, relative intensities of the emission lines, electron density, electron temperature, and chemical abundances were measuered (A.A. Yeghiazarian, M.A. Kazarian, E.Ye. Khachikian).

 

A.A. Egiazaryan, Eh.E. Khachikyan, Spectrophotometry of galaxies with UV excess. IX // Commun. BAO, Vol. 60, p. 13-20, 1988 (and references therein).

 

1976                 Study of the Hubble diagram for Seyfert galaxies and related objects and establishment of the continuity from Seyferts to QSOs. Magnitude-redshift and angular diameter-redshift diagrams were plotted for the sample, and the results were taken as evidence that Seyfert galaxies have cosmological redshifts. The Hb luminosities of Sy1 nuclei and QSOs were compared. It was concluded that QSO redshifts really are cosmological (E.Ye. Khachikian, in collaboration with D.W. Weedman, Cornell University, USA).

 

E.E. Khachikian, D.W. Weedman, The Hubble diagram for Seyfert galaxies and related objects // In: The evolution of the galaxies and its cosmological implications; International Conf., Paris, France, September 8-9, 1976, Proc. Paris, Centre National de la Recherche Scientifique, p. 411-424; Discussion, p. 425, 426. 1977.

 

1979-1983         Discovery and study of double nuclei UV-excess (Markarian) galaxies based on their morphology (A.R. Petrosian, K.A. Sahakian, E.Ye. Khachikian; and A.T. Kalloghlian, in collaboration with astronomers from GDR).

 

A.R. Petrosian, K.A. Sahakian, E.Ye. Khachikian, The New Double Nuclei Markarian Galaxies // Active Galactic Nuclei: Proc. IAU Symp. 134, held in Santa Cruz, California, Aug 15-19, 1988. Ed. D.E. Osterbrock & J.S. Miller. IAU. Symp. #134, Kluwer Academic Publishers, Dordrecht, p. 445, 1989 (and references therein).

 

1983-1984         Discovery and study of superassociations (giant HII regions) in UV-excess (Markarian) spiral galaxies based on their morphology; explanation of their presence as evidence of intensive star-formation in these galaxies. Some statistical analysis concerning the occurrence of superassociations was carried out (A.R. Petrosian, K.A. Sahakian, E.Ye. Khachikian).

 

Petrosian, A. R.; Saakian, K. A.; Khachikian, E. E., Superassociations in spiral galaxies with ultraviolet excess. III // Astrophysics, Vol. 20, No. 4, p. 386-395, 1984 (and references therein).

 

1983-1990         Detailed spectrophotometric studies of some Markarian galaxies (A.R. Petrosian, K.A. Sahakian, N.K. Andreassian, E.Ye. Khachikian, in collaboration with A.N. Burenkov, SAO, Russia).

 

A.N. Burenkov, E.E. Khachikyan, Spectrophotometric Investigation of the Galaxy Markarian 7 // Astrophysics, Vol. 32, No. 2, p. 135, 1990 (and references therein).

 

1984-1985         Study of UV-excess (Markarian) galaxies with jets; galaxies with ejected material in the shape of a rectilinear jet issuing from the nucleus were studied based on observations with the 2.6m telescope, the morphologies and parameters of the galaxies were determined. Some characteristic properties of galaxies with jets were discussed (A.R. Petrosian, K.A. Sahakian, E.Ye. Khachikian).

 

A.R. Petrosian, K.A. Saakian, E.E. Khachikian, Some new ultraviolet galaxies with jets // Astrophysics, vol. 21, no. 2, p. 135-142, 1985.

 

1998                 A possible mechanism of production of additional components in emission lines of the spectra of active galaxies. A new mechanism is suggested to explain the appearance of additional new emission components of hydrogen lines in the spectra of AGNs. An assumption was made that a dense clump of H is ejected from an AGN and expands rapidly due to a presumed explosion. The shift of the additional component reaches several thousand km/sec, and its width, 100-200 A (E.Ye. Khachikian, N.B. Yengibarian).

 

V.A. Ambartsumyan, Eh.E. Khachikyan, N.B. Yengibarian, One mechanism of production of additional components in emission lines of the spectra of active galaxies // Astrophysics, Vol. 41, No. 3, p. 207-213, 1998.

 

1970-1979         Detailed photometric, polarimetric, and spectrophotometric investigation of the variable cometary nebula NGC 2261 and its nucleus, R Mon. It was shown that the radial velocity of the absorption lines of R Mon on the average is -40 km/sec, and the emission line radial velocity is +53 km/sec (by Fe II lines) and +29 km/sec (by H lines). A model of the nebula is proposed in which dense, weakly excited gas flows over a dust cone which is at rest relative to the star, the gas being accelerated along the direction of the cone axis (M.A. Kazarian, T.Yu. Magakian, E.Ye. Khachikian, in collaboration with J.L. Greenstein, USA; E.S. Parsamian).

 

M.A. Kazaryan, Eh.E. Khachikyan, Observations of lambda 3727 [O II] in the spectrum of the cometary nebula NGC 2661 // Astron. Tsirk., No. 592, p. 2-4, 1970.

M.A. Kazaryan, E.E. Khachikyan, Spectrophotometric investigation of the cometary nebula NGC 2261 // Astrophysics, Vol. 8, No. 1, p. 8-16, 1972.

J.L. Greenstein, M.A. Kazaryan, E.E. Khachikyan, Electron density of the cometary nebula NGC 2261 // Soviet Astron. Lett., No. 1, p. 186, 1975.

J.L. Greenstein, M.A. Kazaryan, T.Yu. Magakyan, E.E. Khachikyan, Spectrophotometric investigation of R Mon and NGC 2261. I // Ap, Vol. 12, No. 4, p. 384-402, 1976.

J.L. Greenstein, M.A. Kazaryan, T.Yu. Magakyan, E.E. Khachikyan, Spectrophotometric investigation of R Mon and NGC 2261. II // Ap, Vol. 15, No. 4, p. 411-420, 1979.

 

 

 

1965                 Discovery of many new cometary nebulae. Compilation and publication of the first Catalog of cometary nebulae (E.S. Parsamian).

 

E.S. Parsamian, Catalogue of cometary nebulae discovered on Palomar maps // Izv. Akad. Nauk Armyan. SSR., Ser. Fiz.-Math, Vol. 18, p. 146-148, 1965.

 

?1960s             Search and colorimetric study of Ha emission stars in Orion, Cygnus and Pleiades clusters; the presence of emission shows that these stars are young (E.S. Parsamian, M.A. Kazarian, et al.).

 

1969-1985         Study of megalithic monuments in Karahunge, Metzamor, and Angeghakot; revealing their astronomical significance, their use for observations of Sun, Moon, and planets (E.S. Parsamian).

 

Eh.S. Parsamyan, K.A. Mkrtchian, On the possible astronomical purpose of one of the places found in Metsamor (Armenia) // Istor.-Astron. Issled., Vol. 10, p. 35-37, 1969.

E.S. Parsamian, On Astronomical Meaning of the Small Hill of Metsamor // Communications of BAO, Vol. 57, p. 92-100, 1985.

E.S. Parsamian, On Possible Astronomical Significance of Megalithic Rings of Angelacot // Communications of BAO, Vol. 57, p. 101-103, 1985.

 

1970-1981         Discovery and study of hundreds of flare stars in star clusters and associations (Pleiades, Orion, Hyades, Praesepe, Cygnus (NGC 7000 and NGC 7023), Coma, Mon I, etc.). Investigation of early stages of evolution of dwarf non-stable stars (L.V. Mirzoyan, E.S. Parsamian, H.S. Chavushian, L.K. Erastova, E.S. Kazarian, A.T. Gharibjanian, N.D. Melikian, G.B. Ohanian, V.V. Hambaryan, R.Sh. Natsvlishvili).

 

                                L.V. Mirzoyan, O.S. Chavushyan, G.B. Oganyan, V.V. Ambaryan, A.T. Garibdzhanyan, N.D. Melikyan, R.Sh. Natsvlishvili, Flare Stars in the Pleiades. VI // Astrophysics, Vol. 17, No. 1, p. 38-47, 1981 (and references therein).

 

1971-2000         Discovery and study of new planetary nebulae (E.S. Parsamian, M.A. Kazarian, K.G. Gasparian, in collaboration with L.Parrao, Mexioc).

 

                                M.A. Kazarian, E.S. Parsamian, L. Parrao, Spectrophotometry of three planetary nebulae // Astrophysics, Vol. 43, p. 269-274, 2000 (and references therein).

 

1976                 Statistical investigation of flare stars in star clusters and Solar vicinity; new method of estimation of the age of star clusters and individual flare stars (E.S. Parsamian).

 

E.S. Parsamyan, Dependence of the absolute magnitudes (energies) of flares on the age of the cluster in which the flare stars occur // Astrophysics, Vol. 12, No. 2, p. 145-151, 1976.

 

1979                 Compilation and publication of the new Catalog of cometary nebulae containing 106 objects with declinations between -42° and +66°. A new morphological classification of the objects into four categories was presented: cometary nebulae of conical form (ex. NGC 2261), cometary nebulae of biconical form (ex. Anon 6^h04^m), comma-shaped nebulae (ex. Z CMa), and arc-shaped nebulae (ex. T Tauri) (E.S. Parsamian, V.M. Petrosian).

 

Eh.S. Parsamyan, V.M. Petrosyan, Catalogue of cometary nebulae and related objects (-42 <delta <+66 ) // Commun. BAO, Vol. 51, p. 3-16, 1979 (in Russian).

 

1980                 Study of slow flares in stellar associations; observations of 21 slow flares in Orion, Pleiades, Praesepe, and Hyades associations. The slow flares are attributed to the release of energy below the surface of a flare star. The light curves of slow flares were divided into three types. It was shown that combinations of slow and fast flares could encounter. Dependences were obtained between flare amplitude, the inverse rate of flare-up, and the inverse rate of decay (E.S. Parsamian).

 

E.S. Parsamian, Slow flares in aggregates. I // Astrophysics, Vol. 16, No. 1, p. 60-66, 1980.

E.S. Parsamian, Slow flares in aggregates. II // Astrophysics, Vol. 16, No. 2, p. 140-146, 1980.

 

1980                 Study of the frequency distribution function of stellar flares in the Orion association; the temporal distributions of flare stars and the numbers of stars with different flare frequencies were determined by means of Ambartsumian's (1978) method. It was shown that flare stars with high flare frequency (< 1000^h) in the Pleiades are basically stars of low luminosity with M(U)>13^m. It was estimated that there are about 1.5 times more flare stars in the Orion association than in the Pleiades (E.S. Parsamian).

 

E.S. Parsamian, Frequency distribution function of stellar flares in the Orion association // Astrophysics, Vol. 16, No. 4, p. 391-395, 1980.

 

1982                 Compilation and publication of the catalog of Ha emission stars in the region of the Orion Nebula containing 534 stars in the region of Orion (5°x5°). 255 of these stars were discovered in the studies by Haro (1950, 1953). Haro also called attention to the occurrence of flare-ups in some of the emission lines and to the fact that the intensity of the Ha emission lines varied strongly in a number of spectra. Due to new observations, 240 emission stars were added to Haro's (1953) original list (E.S. Parsamian, in collaboration with E.Chavira, Mexico).

 

E.S. Parsamian, E. Chavira, Catalog of H-alpha emission stars in the region of the Orion Nebula // Instituto de Tonantzintla, Boletin, Vol. 3, p. 69-96, 1982.

 

1985                 Statistical study of flare stars and Ha emission stars in the region of the Orion Nebula. The percentage of flare stars among RW variables with variability range of at least 1^m is shown to be about 40% and among the variables with at least 2^m ranges about 60%. Thus, the higher the RW activity, the higher the percentage of flare stars among them. Among flare stars, about 10% exhibit RW activity. The shapes of the distribution of the flare stars and Ha stars with respect to the magnitude are identical (E.S. Parsamian).

 

E.S. Parsamian, Flare stars and stars with H-alpha in emission in the region of the Orion Nebula // Astrophysics, Vol. 21, No. 1, p. 51-58, 1985.

 

1987-2004         Study of Fuors and Subfuors (Exors); spectral observations of subfuors (E.S. Parsamian, K.G. Gasparian, in collaboration with astronomers from Mexico).

 

E.S. Parsamian, R. Mujica, L. Corral, Spectroscopic Observations of Subfuors (Exors). I. V1118 Ori // Astrophyiscs, Vol. 45, No. 4, p. 393-399, 2002.

E.S. Parsamian, R. Mujica, Spectral Observations of Subfuors (Exors). II. V1143 Ori // Astrophyiscs, Vol. 47, No. 4, p. 433-442, 2004 (and references therein).

 

1995                 Determination of the age of stellar aggregates and flare stars of the galactic field. On the basis of the relationship between the age and the magnitude of the maximal flare amplitude in flare stars, a method was proposed for determining the age of aggregates. The age of the Cyg T1 association (3.4·10⁶ yr) was determined. Upper limits for the ages of some flare stars in the solar neighborhood were given: UV Ceti, EV Lac, AD Leo, EG Peg, YZ CMi, and seven flare stars of the galactic field. The ages vary noticeably (E.S. Parsamian).

 

                                E.S. Parsamyan, Determination of the age of stellar aggregates and flare stars of the galactic field // Astrophysics, Vol. 38, No. 3, p. 206-212, 1995.

 

 

 

1957-1974         Discovery of compact groups of compact galaxies (named Shahbazian groups), objects that are up to present subject for detailed studies (R.K. Shahbazian, M.B. Petrosyan, in collaboration with astronomers from GDR).

 

                                R.K.Shakhbazian // Astron. Circ USSR, No. 177, p. 11, 1957.

                                F.W. Baier, M.B. Petrosyan, H.Tiersch, R.K.Shakhbazian // Astrofizika, Vol. 10, p. 327, 1974 (and references therein).

 

1958                 First discovery of the intrinsic polarization of a star; polarization of radiation of the red supergiant m Cep and its variability; the possibility of non-stationary processes in red supergiants was proved (K.A. Grigorian).

 

1960                 Morphological classification of cometary nebulae (H.S. Badalian).

 

1964                 Discovery of the polarization of radiation of T Tau stars and its variability (R.A. Vardanian).

 

1960s               Solution of general non-linear problems of the radiative transfer theory based on Ambartsumian’s principle of invariance; problems of the polychromatic light scattering in one-dimensional and three-dimensional media (A.G. Nikoghossian, V.Yu. Terebizh).

 

1960s               A new method for solution of the linear problems of non-coherent light scattering based on breakdown of the frequency re-distribution function to its Eigen functions (A.G. Nikoghossian, N.B. Yengibarian).

 

1960s               New methods of solution of mathematical problems of definite type based on the theory of invariance and non-linear functional equations arising in the light scattering theory (M.A. Mnatsakanian, N.B. Yengibarian).

 

1967                 Extended studies of the history of Armenian astronomy: records of comets, meteors, astronomical instruments, etc. (B.E. Tumanian).

 

                                B.E. Tumanian, On the history of Armenian astronomy // Vistas in Astronomy, Vol. 9, No. 1, p. 253-259, 1967.

 

1960-1965         Radio observations and study of the radio spectrum of the Galactic centre (V.H. Malumian).

 

                                V.G. Malumyan, Radio emission of the galactic nucleus // Astrophysics, Vol. 1, No. 3, p. 184-184, 1965 (and references therein).

 

1970-1973         Radio observations of UV-excess (Markarian) galaxies (V.H. Malumian, in collaboration with astronomers from UK).

 

                                M.S. Longair, V.H. Malumian, W.L.W. Sargent, The Radio Emission from Markarian Galaxies // Astrophysical Letters, Vol. 7, p. 23, 1970.

P. Tomasson, V.G. Malumyan, Observations of Markarian galaxies at 75 cm // Izv. Vyssh. Uchebn. Zaved., Radiofiz., Vol. 16, p. 1342-1343, 1973.

P. Thomasson, V.H. Malumian, An attempt to detect radio emission from Markarian galaxies at 408 MHz // Mon. Notices Roy. Astron. Soc., Vol. 162, p. 295, 1973.

                       

1981-1984         Radio observations of galaxies with high surface brightness at 3.95 GHz, 3.66 GHz, and 102 MHz (V.H. Malumian, M.A. Hovhannisyan, G.A. Ohanian).

 

                                V.G. Malumyan, Investigation of galaxies of high surface brightness at 3.95 GHz // Astrofizika, Vol. 20, No. 1, p. 182-186, 1984 (and references therein).

 

1974-1976         Study of the radio variability of QSOs (V.H. Malumian, V.A. Sanamian).

 

                                V.G. Malumyan, V.A. Sanamyan, S.S. Mailyan, Search for variability in 3C 48 and 3C 84 AT 408 MHz // Astrophysics, Vol. 12, No. 3, p. 364-365, 1976 (and references therein).

 

1960s               Discovery of weak polarization of radiation of flare stars (K.A. Grigorian, M.H. Eritsian)

 

1967-1972         Discovery and study of new variables in the star-forming regions; S Mon, NGC 2264, Taurus, etc. (H.S. Badalian, L.K. Erastova).

 

1969                 Classification of photometric light-curves of flares of UV Ceti stars (V.S. Oskanian).

 

V.S. Oskanian, The classification of photometric light-curves of flares of UV Ceti stars // Comm. Konkoly Obs., No. 65 (Vol. VI, 1), p. 131-136, 1969.

 

1969-1974         Photoelectric observations and study of flare stars in the Solar neighbourhood (V.S. Oskanian).

 

1960s-1990s      Search and study of extragalactic supernovae; discovery of dozens of new supernovae. Discovery of 3 supernovae in one galaxy during 6 years (R.K. Shahbazian, S.G. Iskudarian, R.G. Mnatsakanian, A.R. Petrosian).

 

1970-1983         Electrophotometric and polarimetric observations and studies of UV Ceti type flare stars in the Solar neighbourhood and T Tau stars (R.A. Vardanian, V.S. Oskanian, M.H. Eritsian, K.A. Grigorian N.D. Melikian, et al.).).

 

M.H. Eritsian, Polarimetric and Photometric Observations of Five Flares on the Star EV Lacertae // Commun. BAO, Vol. 54, p. 24, 1983 (and references therein).

 

1971                 Investigation of the characteristics of the flare activity and time distribution of flares of UV Ceti type stars (V.S. Oskanian, V.Yu. Terebizh).

 

                                V.S. Oskanyan, V.Yu. Terebizh, Some characteristics of the flare activity of UV Cet type stars. I // Astrophysics, Vol. 7, No. 1, p. 48-54, 1971.

V.S. Oskanyan, V.Yu. Terebizh, Some characteristics of the flare activity of UV Ceti type stars. II // Astrophysics, Vol. 7, No. 2, p. 164-171, 1971.

V.S. Oskanyan, V.Yu. Terebizh, Some Remarks Concerning the Time-Distribution of Flares of UV Ceti Type Stars // IBVS, No. 535, p. 1, 1971.

 

1971                 Designing and building of a stellar electropolarimeter with a fast rotating polaroidal modulator for the 40cm telescope (M.H. Eritsian).

 

M.A. Eritsian, A stellar electropolarimeter with a fast rotating polaroidal modulator // Soobshch. Byurakan Obs., No. 43, p. 33-48, 1971 (in Russian).

 

1972                 New approach in solutions of radiation transfer problems for finite layers with application of principle of invariance for semi-infinite thickness layers, which allowed finding approximate analytical solutions of the problem of monochromatic radiation transfer (M.A. Mnatsakanian).

 

1970s               Building of a strict mathematical apparatus for the solution of problems of radiative transfer in plain-parallel medium due to application of the principle of invariance. A direct relation was established between the solutions of non-linear problems and the renormalization groups known from the quantum theory (M.A. Mnatsakanian).

 

1975-1982         Study of the variability of UV-excess (Markarian) galaxies (K.A. Sahakian).

 

1977                 Discovery of 60 new cometary nebulae based on inspection of Palomar atlases (A.L. Gyulbudaghian, T.Yu. Magakian).

 

1977                 Discovery and study of the variability of cometary nebulae (A.L. Gyulbudaghian, T.Yu. Magakian, A.S. Amirkhanian).

 

                                A.L. Giulbudagian, T.Yu. Magakian, A.S. Amirkhanian, Conspicuous changes in the shape of two cometary nebulae // Soviet Astronomy Letters, Vol. 3,p. 84-85, 1977.

 

1977                 Establishing a relation between the radiation fields in semi-infinite and finite media containing isotropic energy sources; asymptotic expressions are given for obtaining the internal radiation fields both far from and near the energy source. (E.Kh. Danielian, H.V. Pikichian).

 

E.Kh. Danielyan, O.V. Pikichyan, Radiation field in a plane-parallel atmosphere containing energy sources // Astrophysics, Vol. 13, No. 2, p. 147-154, 1977.

 

1970s               Radio investigation of cometary nebulae and HH objects connected to maser sources; definition of their structure and detection of variability of some sources (V.A. Sanamian, R.A. Kandalyan).

 

1978                 Derivation of an equation for Ambartsumian's (1942) phi function by using two relations that associate the phi function with Sobolev's resolvent function. The calculation of the phi function from the derived equation is shown to be more effective than the standard procedure (R.R. Andreasyan, E.Kh. Danielian).

 

R.R. Andreasian, E.Kh. Danielian, On the calculation of Ambartsumian's phi function // Commun. BAO, No. 50, p. 114-117, 1978 (in Russian).

 

1979                 New method for definition of the frequency of supernovae of the two types separately. It was shown that the mean frequency of type II SNe is twice that of type I SNe, and that the mean frequency of SNe in Sc galaxies is proportional to the luminosity of the parent galaxy  The frequency of supernovae was studied in Sb and Sc galaxies (R.G. Mnatsakanian, Arm.V. Oskanian, in collaboration with M. Lovash, Hungary).

 

                                R.G. Mnatsakanyan, A.V. Oskanyan, M. Lovash, On the frequency of supernovae // Astrophysics, Vol. 15, No. 3, p. 281-286, 1979.

                                R.G. Mnatsakanyan, Frequency of supernova explosions in Sb galaxies // Astrophysics, Vol. 21, No. 1, p. 401-404, 1984 (and references therein).

 

1970s               It was shown that active galaxies have flat radio spectrum, which proves that they are young (V.H. Malumian).

 

1970s-1980s      Discovery of new galaxies with UV-excess, named Kazarian galaxies (at present more than 700 objects) (M.A. Kazarian, E.S Kazarian).

 

1980-1990         Study of the structure of the magnetic field of our Galaxy; the two-component model of the Galactic magnetic field, its structure in the direction of spiral arms, etc. (R.R. Andreasyan, A.N. Makarov).

 

1980s               Radio observations of Markarian galaxies (mainly of Seyfert type) on Russian RATAN-600 telescope (V.A. Sanamian, R.A. Kandalyan).

 

1980s               Investigation of the structure and composition of clusters of galaxies based on detailed morphological study and colorimetry of their members. Study of the luminosity function of clusters (A.T. Kalloghlian).

 

1980s               Suggestion of cosmogonic hypothesis connected with Ambartsumian’s cosmogonic theory, which allows explaining the origin of the rotation of cosmic objects (stars and galaxies) from the quantitative point of view based on the relation between the rotational moment and mass of the elementary particles known in the particle physics (R.M. Muradian).

 

1980s               Suggestion of formation of heavy elements in the atmospheres of stars with anomalous chemical composition based on Ambartsumian’s hypothesis of superdense matter; by means of decay of the superdense matter in atmospheres (Yu.K. Melik-Alaverdian).

 

1984-1985         Study of the distribution of OB stars and absorbing matter in the region around P Cyg; 281 stars were studied. Concentrations of OB stars with associated absorbing matter toward the associations Cyg OB1, Cyg OB3, Cyg OB8, Cyg OB9, and over the entire observed region at a distance of about 500 pc were found (A.T. Gharibjanian, K.G. Gasparian, R.Kh. Hovhannessian).

 

A.T. Garibdzhanyan, K.G. Gasparyan, R.Kh. Oganesyan, Distribution of OB-Stars and Absorbing Matter in the Region around P-Cygni // Astrophysics, Vol. 20, No. 2, p. 129, 1984.

                                R.Kh. Oganesyan, A.T. Garibdzhanyan, K.G. Gasparyan, Relative and absolute energy distribution in the spectra of OB-stars in the region around P Cyg // Comm. BAO, No. 57, p. 58 - 64, 1985.

 

1984-2002         Study of the magnetic fields of extragalactic radio sources; correlation between the directions of the magnetic fields and major axes, mechanism of formation of a dipole magnetic field, etc. (R.R. Andreasyan).

 

                                R.R. Andreasyan, S. Appl, H. Sol, Correlation between the Directions of the Magnetic Fields and Major Axes of Extragalactic Radio Sources // Astrophysics, Vol. 45, No. 2, p. 198-204, 2002 (and references therein).

 

1984-2004         Spectroscopic studies of the Second Byurakan Survey galaxies aimed at study of the sample at B<17; discovery of many new Seyferts, LINERs, Starbursts, BCDGs, etc. (J.A. Stepanian, L.K. Erastova, V.H. Chavushian, H.M. Tovmassian, in collaboration with astronomers from Mexico; S.K. Balayan, S.A. Hakopian, in collaboration with astronomers from the Special Astrophysical Observatory, Russia).

 

J.A. Stepanian, V.H. Chavushyan, L. Carrasco, J.R. Valdes, R.M. Mujica, H.M. Tovmassian, V.T. Ayvazyan, Spectral Observations of Faint Markarian Galaxies of the Second Byurakan Survey. III // Astron. J., Vol. 124, No. 3, p. 1283-1307, 2002 (and references therein).

 

1985-1986         Detailed spectrophotometric studies of carbon stars; spectral energy distribution, molecular absorption bands, etc. (S.Ye. Nersessian, R.Kh. Hovhannessian, M.Sh. Karapetian).

 

S.E. Nersisyan, R.Kh. Oganesyan, Spectrophotometry of Carbon Stars. III. Molecular Absorption Bands: Quantitative Analysis // Astrophysics, Vol. 24, No. 2 p. 142-149, 1986 (and references therein).

 

1987-2007         Spectral and photometric study of Shahbazian compact groups of compact galaxies; it was shown that 7-10% of member galaxies in Shahbazian compact groups are emission-line galaxies including classical Sy1-s and narrow-emission-line galaxies (A.S. Amirkhanian, A.G. Egikian).

                                               

                                A.S. Amirkhanian, E.Ye. Khachikian, A.G. Eghikian, Spectral and photometric study of compact groups of compact galaxies // Astrophysics, Vol. 50, No. 3, p. 283-288, 2007 (and references therein).

 

1988-1990         Statistical study of the Galactic star-formation regions (Arm.V. Oskanian).

 

A.V. Oskanyan, Statistical analysis of galactic H II regions observed in the continuum and in the radio line Ha 110. II // Astrophysics, Vol. 30, No. 1, p. 75, 1989 (and references therein).

A.V. Oskanyan, Regions of active star formation in O associations. II // Astrophysics, Vol. 33, No. 2, p. 447-453, 1990 (and references therein).

 

1988-2007         Suggestion of new criteria for identification of groups of galaxies based on the neighbourhood of pairs. Statistical investigation of groups (A.P. Mahtessian).

 

A.P. Mahtessian, Groups of galaxies. IV. Effect of observational selection on the relationship between the characteristics and distance of groups and a comparison with the groups of Geller and Huchra // Astrophysics, Vol. 50, No. 4, p. 440-450, 2007 (and references therein).

 

1989-1990s       New method of detection of stellar flares by tracks for study of flare stars with high time resolution. Discovery of dozens of new flares with this method (H.S. Chavushian).

 

1986-1991         Observations of maser radiation in the principal lines of the OH molecule; study of stellar and non-stellar masers (R.A. Kandalyan, F.S. Nazaretyan, V.A. Sanamyan, in collaboration with astronomers from Russia).

 

                                I.V. Gosachinskii, R.A. Kandalyan, F.S. Nazaretyan, V.A. Sanamyan, N.A. Yudaeva, Variability of H₂O maser sources at wavelength 1.35 cm. III. Nonstellar masers // Astrophysics, Vol. 33, No. 2, p. 427-433, 1990 (and references therein).

 

1993-2001         Determination of the radio luminosities of pulsars and the distribution of interstellar electron density based on the pulsars periods and the time variation of the period. Independent distances were determined for pulsars and the average electron densities toward the pulsars were determined from the known dispersion measures. It was shown that the distribution maximum lies in the vicinity of the Sagittarius spiral arm (R.R. Andreasyan, T.G. Arshakian).

 

R.R. Andreasyan, T.G. Arshakian, The radio luminosity of pulsars and the distribution of interstellar electron density // Astrophys. Space Sci., Vol. 278, No. 1/2, p. 175-179, 2001 (and references therein).

 

1998                 Study of the Trapezium Ori type multiple stars; proof of their instability (V.V. Hambaryan, L.V. Mirzoyan, in collaboration with astronomers from Abastumani Astrophysical Observatory, Georgia).

 

                                L.V. Mirzoyan, G.N. Salukvadze, V.V. Hambaryan, G.Sh. Javakhishvily, Trapezium Type Multiple Stars – Instable Systems // Astrophysics, Vol. 41, p. 59, 1998 (and references therein).

 

1990s-2001       Studies of the structure of Abell clusters of galaxies (E.H. Nikogossian).

 

E.H. Nikogossian, Structure of the Clusters of Galaxies A 2634, A 1983, and DC 0428-53 // Astrophysics, Vol. 44, No. 3, p. 305-314, 2001 (and references therein).

 

1990s-2000s      Detailed studies of young stellar objects: HH objects, cometary nebulae, T Tau stars, and associated jets. Studies include imaging, spectroscopic (including integral field spectroscopy), and near-IR observations (T.Yu. Magakian, T.H. Movsessian, E.H. Nikogossian, E.R. Hovhannessian, in collaboration with astronomers from Russia, USA, and UK).

 

1990s-2007       Multi-wavelength studies of a new sample of blue compact dwarf galaxies selected from SBS (A.R. Petrosian, in collaboration with astronomers from France, Germany, and India).

 

1997                 The first year of the Armenian calendar was determined. It was shown that the year 961 given in Parzatumar corresponds to 1512, putting the beginning of the Armenian calendar to 551 (G.H. Broutian).

 

1997-2000         X-ray studies of flare and T Tau type stars; detection of flares based on the shape of the ROSAT X-ray light-curves using the formalism of Bayesian model comparison (V.V. Hambaryan, in collaboration with astronomers from MPE, Garching, Germany).

                                               

                                B. Stelzer, R. Neuhauser, V.V. Hambaryan, X-ray flares on zero-age- and pre-main sequence stars in Taurus-Auriga-Perseus // Astron. Astrophys., Vol. 356, p. 949-971, 2000 (and references therein).

 

1998                 Suggestion of a new microscopic theory of the standard model of the elementary particles, which can explain many fundamental problems arising in the modern phenomenological typical model of the elementary particles (G.T. Ter-Kazarian).

 

1998-2001         Multiwavelength studies of barred galaxies (A.T. Kalloghlian, R.A. Kandalyan, V.G. Panajyan, in collaboration with astronomers from Jordan).

 

A.T. Kalloghlian, R.A. Kandalyan, H.M.K. Al-Naimiy, A.M. Khassawneh, Investigation of Barred Galaxies. VII. Comparative Statistics of SB and SA Galaxies. Near and Mid-IR Regions // Astrophysics, Vol. 44, No. 3, p. 292-304, 2001 (and references therein).

 

1990s-2006       Discovery of new dark globules in the star forming regions and rotation of some of them (A.L. Gyulbudaghian, in collaboration with astronomers from Spain and Chile).

 

1999                 Designing and building an integral field spectrograph (VAGR) for the 2.6m telescope (T.H. Movsessian, in collaboration with astronomers from France).

 

T.H. Movsessian, J.-L. Gach, J. Boulesteix, F. Zhamkotsian, The Integral Field Spectrograph for the 2.6 m // Baltic Astronomy, Vol. 9, p. 518-522, 2000.

 

2000                 Suggestion of an asymmetric relativistic model for classical double radio sources based on the statistical analysis of FRII sources from the 3CRR complete sample (T.G. Arshakian, in collaboration with M.S. Longair, Cavendish Laboratory, Cambridge University, UK).

 

T.G. Arshakian, M.S. Longair, An asymmetric relativistic model for classical double radio sources // Mon. Notices Roy. Astron. Soc., Vol. 311, No. 4, p. 846-860, 2000.

 

2000-2001         Studies of the relationship between infrared and radio emission of various types of galaxies, including Seyferts and LINERs (V.H. Malumian, V.G. Panajyan).

 

2001                 Discovery of gas-dust shells around 34 early type stars with IR excess based on IRAS observations of O-B-A-F type stars (R.Kh. Hovhannessian, E.R. Hovhannessian).

 

R.Kh. Hovhannessian, E.R. Hovhannessian, Gas-Dust Shells around Some Early-Type Stars with an IR Excess (of Emission) // Astrophysics, Vol. 44, No. 4, p. 454-462, 2001.

 

2001                 Study of the formation of heavy hydrocarbons in molecular clouds. Laboratory data on the conversion of solid methane into large hydrocarbons by particle radiation were used to estimate the fraction of interstellar carbon converted by this process into refractory form (Ar.G. Yeghikian, in collaboration with scientists from University College London, UK).

 

                                A. G. Yeghikyan, S. Viti, D.A. Williams, The formation of heavy hydrocarbons in molecular clouds // Mon. Notices Roy. Astron. Soc., Vol. 326, No. 1, p. 313-316, 2001.

 

2001-2002         Interpretation of the radiation of the coronal suprathermal streams by the effect of Compton scattering of the photospheric radiation on fast electrons of the coronal suprathermal streams (A.G. Nikoghossian, in collaboration with S. Koutchmy, France).

 

A.G. Nikoghossian, S. Koutchmy, Interpretation of the Radiation of Coronal Suprathermal Streams. I // Astrophyiscs, Vol. 44, No. 4, p. 528-535, 2001.

A.G. Nikoghossian, S. Koutchmy, On Interpretation of the Radiation of Coronal Suprathermal Streams. II // Astrophyiscs, Vol. 45, No. 4, p. 489-496, 2002.

 

2002-2003         Extended studies of the Second Byurakan Survey galaxies (A.R. Petrosian, in collaboration with Space Telescope Science Institute, USA).

 

A.R. Petrosian, B. McLean, R.J. Allen, et al., Studies of the Second Byurakan Survey Galaxies. I. Mergers, Interacting Systems, and Close Pairs // Astron. J., Vol. 123, No. 5, p. 2280-2301, 2002.

A.R. Petrosian, R.J. Allen, C. Leitherer, et al., Studies of the Second Byurakan Survey Galaxies. II. Comparison of Ultraviolet-excess and Emission-line Techniques // Astron. J., Vol. 125, No. 1, p. 86-97, 2003.

 

2003                 Compilation and publication of the Merged catalogue of reflection nebulae, the most complete reference list for these objects (T.Yu. Magakian). 

 

                                T.Yu. Magakian, Merged catalogue of reflection nebulae // Astron. Astrophys., Vol. 399 No. 1, p. 141-145, 2003. VizieR On-line Data Catalog: J/A+A/399/141.

 

2003                 Obtaining accurate BVIJHK period-luminosity relations for classical Cepheids in the Galaxy and Magellanic clouds (H.V. Abrahamian).

 

                                H.V. Abrahamyan, Period-Luminosity Relations for Classical Cepheids // Astrophysics, Vol. 46, No. 4, p. 455-464, 2003.

 

2003                 Suggestion of a unified phenomenological model of light curves of stellar flares to explain a wide variety of flares. An assumption was made that a flare consists of a fast and relatively strong rise in brightness followed by a slow and fainter component. The latter is a result of re-radiation of the part of the energy of the prime flare by the photosphere of the star (V.P. Zalinian, in collaboration with astronomers from Mexico).

 

H.M. Tovmassian, V.P. Zalinian, N.A. Silant'ev, O. Cardona, M. Chavez, The unified phenomenological model of light curves of stellar flares // Astron. Astrophys., Vol. 399, No. 2, p. 647-651, 2003.

 

2003-2007         Studies of radio and X-ray properties of OH megamaser galaxies (R.A. Kandalyan).

 

R.A. Kandalyan, Some Features of the X-Ray and Radio Emission from OH Megamaser Galaxies // Astrophysics, Vol. 48, No. 3, p. 355-362, 2005 (and references therein).

 

2003-2008         Suggestion that cD galaxies are generators of the clusters in which they occur based on the observed features of cD galaxies and the associated clusters, while all the galaxies of a given cluster are products of the activity of a central supergiant galaxy. A physical connection between activity phenomena and cosmic expansion is sought (H.A. Harutyunian).

 

H.A. Harutyunian, Fragmentation of Cosmic Objects in the Course of their Evolution and the Possible Role of Hubble Expansion in this Process // Astrophysics, Vol. 46, No. 1, p. 81-91, 2003.

H.A. Harutyunian, On the nature of cD galaxies // Astrophysics, Vol. 51, No. 2, p. 141-152, 2008.

 

2003-2008         Search for Herbig-Haro objects and emission-line stars in star formation regions. Several dozens of new HH objects and emission stars have been discovered (T.Yu. Magakian, T.H. Movsessian, E.H. Nikogossian).

 

T.H. Movsessian, T.Yu. Magakian, E.H. Nikogossian, J. Bally, Searches for HH objects and emission stars in star formation regions. V. Two new cometary nebulae in Perseus // Astrophysics, Vol. 51, No. 2, p. 181-188, 2008 (and references therein).

 

2003-2008         Detailed investigation of visual binary stars: orbits, dynamical masses, parallaxes, MK types, etc. (N.D. Melikian, A.A. Karapetian, in collaboration with astronomers from Spain and Russia).

 

J.A. Docobo, V.S. Tamazian, M. Andrade, N.D. Melikian, A.A. Karapetian, Refining the Parallax in Visual Double Stars Using Orbital and Spectral Data: Application to the System of the K0 Giants, A 1808 // Astron. J., Vol. 136, No. 2, p. 890-894, 2008 (and references therein).

 

2004                 The hypothesis of possible anomalous redshift in spectra of young objects based on counts of faint blue objects, considered under the assumption that a large fraction of quasars are local objects ejected from galactic nuclei. This approach was used to examine the problem of excess of blue galaxies (H.A. Harutyunian).

 

                                H.A. Harutyunian, Counts of Faint Blue Objects and the Anomalous Red Shift // Astrophysics, Vol. 47, No. 4, p. 538-546, 2004.

 

2004                 A new approach was proposed for solution of the simplest one-dimensional problem of diffuse reflection and transmission of radiation in inhomogeneous atmospheres with finite optical thicknesses, based on Ambartsumian's method of adding layers. The approach was used to solve the radiative transfer problem in scattering and absorbing multicomponent atmospheres (A.G. Nikoghossian).

 

A.G. Nikoghossian, Radiative Transfer in Inhomogeneous Atmospheres. I // Astrophysics, Vol. 47, No. 1, p. 104-116, 2004.

A.G. Nikoghossian, Radiative Transfer in Inhomogeneous Atmospheres. II // Astrophysics, Vol.  47, No. 2, p. 248-259, 2004.

A.G. Nikoghossian, Radiative Transfer in Inhomogeneous Atmospheres. III // Astrophysics, Vol.  47, No. 3, p. 412-421, 2004.

 

2004                 Publication of the catalog of 216 stars with probable circular polarization; selection is made from the Catalog of starlight polarization (7500 stars) (M.H. Eritsian).

 

                                M.A. Eritsian, Circular Polarization of Starlight // Astrophysics, Vol. 47, No. 3, p. 305-312, 2004. VizieR On-line Data Catalog: J/other/Ap/47.305.

 

2004-2006         Statistical studies of pulsars: spatial distribution, age dependence of several parameters of the radiation, and relation to the supernovae remnants (V.H. Malumian, A.N. Harutyunyan).

 

V.H. Malumian, A.N. Harutyunyan, Spatial Distribution of Pulsars // Astrophysics, Vol. 47, No. 4, p. 568-572, 2004.

V.H. Malumian, A.N. Harutyunyan, Age Dependence of Several Parameters of the Radiation from Radio Pulsars // Astrophysics, Vol. 48, No. 2, p. 188-193, 2005.

V.H. Malumian, A.N. Harutyunyan, Relation of pulsars to the remnants of supernova bursts // Astrophysics, Vol. 49, No. 1, p. 88-95, 2006.

 

2004-2007         A new survey of cool carbon stars in the halo based on 2MASS. Discovery of very red and distant objects (K.S. Gigoyan, in collaboration with astronomers from France and UK).

 

N. Mauron, M. Azzopardi, K. Gigoyan, T.R. Kendall, Cool carbon stars in the halo: A new survey based on 2MASS // Astron. Astrophys., Vol. 418, No. 1, p. 77-88, 2004.

N. Mauron, T.R. Kendall, K. Gigoyan, Cool carbon stars in the halo. II. A study of 25 new objects // Astron. Astrophys., Vol. 438, No. 3, p. 867-874, 2005.

N. Mauron, K. Gigoyan, T.R. Kendall, Cool carbon stars in the halo: new very red or distant objects // Astron. Astrophys., Vol. 475, No. 3, p. 843-849, 2007.

 

2007                 Compilation and publication of the Optical Database and Atlas of Markarian galaxies (A.R. Petrosian, in collaboration with Space Telescope Science Institute, USA).

 

A.R. Petrosian, B. McLean, R.J. Allen, J.W. MacKenty, Markarian Galaxies. I. The Optical Database and Atlas // Astrophys. J. Suppl., Vol. 170, No. 1, p. 33-70, 2007.

 

 

 

1987-2003         The Second part of the FBS, search for blue stellar objects and late-type stars on the FBS plates. 1103 blue stellar objects and 1000 late-type stars were revealed, including many new QSOs, white dwarfs, cataclysmic variables, carbon stars, etc. (H.V. Abrahamian, A.M. Mickaelian, K.S. Gigoyan, P.K. Sinamyan).

 

K.S. Gigoyan, H.V. Abrahamian, et al., First Byurakan Spectral Sky Survey. Stars of Late-Spectral Types. XIV. Zone +13°<DEC<+33° // Astrophysics, Vol. 46, No. 4, p. 475-488, 2003 (and references therein). H.V. Abrahamian, 2007, VizieR On-line Data Catalog: III/246.

 

1995-2004         Optical identifications and studies of IRAS infrared sources. 1577 IRAS point sources were identified using the FBS spectra and DSS images. Many new IR galaxies (including LIRGs and ULIRGs, as well as AGNs and interacting/merging pairs and groups) and IR-excess stars were revealed (A.M. Mickaelian, K.S. Gigoyan, L.A. Sargsyan).

 

A.M. Mickaelian, Optical Identifications of the IRAS Point Sources Based on the First Byurakan Survey // Astrophysics, Vol. 38, No. 4, p. 349-351, 1995.

A.M. Mickaelian, L.A. Sargsyan, Optical identifications of IRAS Point Sources. Galaxies. X // Astrophysics, Vol. 47, No. 2, p. 213-228, 2004 (and references therein).

 

1997-2001         Spectral investigation of Byurakan-IRAS Galaxies (BIG). (A.M. Mickaelian, S.K. Balayan, S.A. Hakopian, L.A. Sargsyan, in collaboration with astronomers from France and Russia).

 

1999-2001         Discovery of new bright QSOs in the FBS and estimation of their surface density (0.012 deg^-2). Estimation of the completeness of the Bright Quasar Survey (53%) (A.M. Mickaelian, in collaboration with astronomers from France).

 

A.M. Mickaelian, A.C. Gonзalves, M.P. Vйron-Cetty, P. Vйron, On the nature of the FBS blue stellar objects and the completeness of the Bright Quasar Survey // Astrophysics, Vol. 42, No. 1, p. 1-14, 1999.

A.M. Mickaelian, A.C. Gonзalves, M.P. Vйron-Cetty, P. Vйron, On the nature of the FBS blue stellar objects and the completeness of the Bright Quasar Survey. II // Astrophysics, Vol. 44, No. 1, p. 14-22, 2001.

 

2001                 Estimation of the maximum IR luminosity of a single spiral galaxy. It was shown that all IR sources with luminosities higher than L_IR=10¹²L_Sun must be interacting/merging pairs (A.M. Mickaelian, in collaboration with P. Vйron and M.P. Vйron-Cetty, OHP, France).

 

A.M. Mickaelian, M.P. Vйron-Cetty, P. Vйron, What is the Maximum IR Luminosity of a Single Spiral Galaxy? // Proc. IAU Symp. 205, ASP, Vol. 205, p. 232-233, 2001.

 

2002-2004         Optical identifications and studies of ROSAT X-ray sources. A large number, 5908 sources from ROSAT-FSC catalogue were identified using the Hamburg survey spectra and DSS images. The Byurakan/Hamburg/ROSAT Catalogue (BHRC) was published. 42 new bright AGN were discovered (A.M. Mickaelian, S.K. Balayan, et al., in collaboration with D. Engels, et al., Hamburger Sternwarte, Germany).

 

M.P. Vйron-Cetty, S.K. Balayan, A.M. Mickaelian, et al., Optically bright AGNs in the ROSAT Faint Source Catalogue // Astron. Astrophys., Vol. 414, p. 487-496, 2004.

A.M. Mickaelian, L.R. Hovhannisyan, D. Engels, H. Hagen, W. Voges, The Byurakan/Hamburg/ROSAT Catalogue of optical identifications // Astron. Astrophys., Vol. 449, No. 1, p. 425-433, 2006. VizieR On-line Data Catalog: J/A+A/449/425.

 

2002-2005         Digitization of the FBS and creation of the largest spectroscopic database, the Digitized First Byurakan Survey (DFBS). 20,000,000 low-dispersion spectra (A.M. Mickaelian, L.A. Sargsyan, et al., in collaboration with Universita di Roma “La Sapienza”, Italy and Cornell University, USA).

 

A.M. Mickaelian, R. Nesci, C. Rossi, et al., The Digitized First Byurakan Survey – DFBS // Astron. Astrophysics, Vol 464, No. 3, p. 1177-1180, 2007.

 

2005                 Creation of the Armenian Virtual Observatory (ArVO) and its acceptance in the International Virtual Observatory Alliance (IVOA) (A.M. Mickaelian).

 

2006                 Compilation and publication of the Catalog of Byurakan-IRAS Stars (BIS). Multiwavelength data are given (A.M. Mickaelian, K.S. Gigoyan).

 

A.M. Mickaelian, K.S. Gigoyan, Revised and Updated Byurakan-IRAS Star Catalog // Astron. Astrophysics, Vol. 455, No. 2, p. 765-772, 2006. VizieR On-line Data Catalog: III/237A.

 

2006-2008         Spectral investigation of the FBS blue stellar objects; revealing many new white dwarfs, hot subdwarfs, cataclysmic variables, and a new planetary nebula. Estimation of the content of the FBS (P.K. Sinamyan, A.M. Mickaelian).

 

                                P.K. Sinamyan, A.M. Mickaelian, Spectral observations of blue stellar objects from FBS in the zone d = +43° // Astrophyiscs, Vol. 49, No. 3, p. 333-349, 2006.

                                P.K. Sinamyan, A.M. Mickaelian, Spectral observations of blue stellar objects from FBS in the zone d = +39° // Astrophyiscs, Vol. 51, No. 1, p. 37-47, 2008.

                                P.K. Sinamyan, A.M. Mickaelian, Spectral observations of FBS blue stellar objects in the zone d = +35° // Astrophyiscs, Vol. 51, No. 2, p. 226-232, 2008.

 

2007                 Discovery of 28 highest IR/optical flux ratio extragalactic objects (having IR/opt up to 1110) by means of selection of sources from IRAS-FSC and observations with Spitzer Space Telescope (SST). The sample filled in the gap between the IRAS discovered ULIRGs and Spitzer discovered 24 mm sources at z~2. The highest luminosity ULIRG was found (10^46.6 erg/sec at 5.5 mm) (A.M. Mickaelian, L.A. Sargsyan, in collaboration with D.W. Weedman and J.R. Houck, Cornell University, USA).

 

L.A. Sargsyan, A.M. Mickaelian, D.W. Weedman, J.R. Houck, Spitzer IRS Spectra of Optically Faint IRAS Sources // Astrophys. J., Vol. 683, No. 1, p. 114-122, 2008.

 

2008                 Compilation and publication of the Catalog of 1103 FBS blue stellar objects. Multiwavelength data are given (A.M. Mickaelian).

 

A.M. Mickaelian, Revised and Updated Catalogue of the FBS Blue Stellar Objects // Astron. J., Vol. 136, No. 3, p. 946–953, 2008. VizieR On-line Data Catalog: III/258.