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Isaac Newton Institute of Chile in Eastern Europe and Eurasia Casilla 1 Isaac Newton Institute of Chile in Eastern Europe and Eurasia Casilla 8-9, Correo 9, Santiago, Chile e-Mail: [email protected] Web-address: www.ini.cl ͓S0002-7537͑95͒03301-4͔ The Isaac Newton Institute, ͑INI͒ for astronomical re- and luminosity functions ͑LFs͒ of the cluster Main Sequence search was founded in 1978 by the undersigned. The main ͑MS͒ for two fields extending from a region near the center office is located in the eastern outskirts of Santiago. Since of the cluster out to Ӎ 10 arcmin. The photometry of these 1992, it has expanded into several countries of the former fields produces a narrow MS extending down to VӍ27, Soviet Union in Eastern Europe and Eurasia. much deeper than any previous ground based study on this As of the year 2003, the Institute is composed of fifteen system and comparable to previous HST photometry. The V, Branches in nine countries ͑see figure on following page͒. V-I CMD also shows a deep white dwarf cooling sequence These are: Armenia ͑19͒, Bulgaria ͑28͒, Crimea ͑35͒, Kaza- locus, contaminated by many field stars and spurious objects. khstan ͑18͒, Kazan ͑12͒, Kiev ͑11͒, Moscow ͑23͒, Odessa We concentrate the present work on the analysis of the ͑35͒, Petersburg ͑33͒, Poland ͑13͒, Pushchino ͑23͒, Special MSLFs derived for two annuli at different radial distance Astrophysical Observatory, ‘‘SAO’’ ͑49͒, Tajikistan ͑9͒, from the center of the cluster. Evidence of a clear-cut corre- Uzbekistan ͑24͒ and Yugoslavia ͑23͒. The quantities in pa- lation between the slope of the observed LFs before reaching rentheses give the number of scientific staff, the grand total the turn-over, and the radial position of the observed fields of which is 355 members. inside the cluster area is found. They find that the LFs be- come flatter with decreasing radius ͑x Ӎ 0.15 for 1 arcmin 1. RESEARCH IN CHILE Ͻ R1 Ͻ 5.5 arcmin;xӍ 0.24 for 5.5 arcmin Ͻ R2 Ͻ 9.8 The primary research program of the Institute in Chile arcmin; core radius, rcϭ 0.05 arcmin), a trend that is continues to be observational studies of globular clusters in consistent with the interpretation of NGC 6397 as a dynami- the Galaxy and the Magellanic Clouds. In addition, a number cally relaxed system. This trend is also evident in the mass of open clusters have been observed. In this field around 200 function ͑2004, A&A, 425, 509-518͒. papers have been published. Besides the above named Branches, following the Con- 2. THE INI ARMENIAN BRANCH vention of Scientific Collaboration with the Rome Observa- The Isaac Newton Institute opened its Branch in Armenia tory of February 2000, Gonzalo Alcaino and Franklin Alva- in June 2000. The formal Agreement has been signed with rado are involved with Italian astronomers in several Prof. Edward Khachikian, at that time the Director of the research projects using data secured from telescopes in Byurakan Astrophysical Observatory of the Armenian Na- Chile. tional Academy of Sciences. CCD photometric analysis has now been completed by The staff of the Isaac Newton Institute Armenian Branch Gonzalo Alcaino, Franklin Alvarado, Guiseppe Bono and consists of 17 scientists: Hamlet Abrahamian, Smbat Bal- Gianni Marconi for the globular clusters NGC 1261, ayan, Kamo Gigoyan, Armen Gyulbudaghian, Lidia Eras- NGC 1851 and NGC 3201. The work is being prepared for tova, Susanna Hakopian, Haik Harutyunian, Rafik Kanda- submission. lyan, Arthur Karapetian, Tigran Magakian, Norair Melikian, As from 2004, a systematic program of CCD data reduc- Areg Mickaelian, Tigran Movsessian, Hripsime Na- tion obtained at La Silla and Las Campanas by Gonzalo Al- vasardyan, Arthur Nikoghossian, Elena Nikogossian, and caino and Franklin Alvarado is ongoing with Nikolai Samus Artashes Petrosian. The Resident Director of the INI Arme- and Alexei Mironov from INI-Moscow Branch. Around 50 nian Branch is Areg Mickaelian. stars clusters will compose the envisaged project in the forth- The Byurakan Astrophysical Observatory ͑BAO͒ is the coming years. main astronomical institution in Armenia and one of the G. Alcaino, F. Alvarado, A. Mironov and N. Samus are most important observatories of the Former Soviet Union. It now engaged in final reductions and data evaluations for was founded by the outstanding scientist Victor Ambartsum- CCD photometry in the globular cluster NGC 6864 ͑a tri- ian in 1946. First studies at BAO related with the instability modal HB Galactic Globular Cluster͒ acquired and initially phenomena taking place in the Universe, and this trend be- reduced by INI in Chile came the main characteristic of the science activity in Byura- G. Alcaino, F. Alvarado, with data obtained at VLT kan. Discovery of the stellar associations ͑1947͒, the hypoth- ͑FORS-1͒ ESO Paranal in a joint study with Gloria An- esis about activity of galactic nuclei ͑1958͒, the famous First dreuzzi, Vincenzo Testa, Gianni Marconi, and Roberto Buo- and Second Byurakan surveys ͑FBS, 1965-80, and SBS, nanno, analyzed the Galactic Globular Cluster NGC 6397, 1978-91͒, the discovery and study of many QSOs and Sey- covering a relatively wide area spanning radial distances fert galaxies, the discovery of some 1000 flare stars, dozens from the cluster center 1ЈϽrϽ9.8Ј, they present ͑V, V-I͒ of Supernovae, hundreds of Herbig-Haro objects and come- VLT-FORS1 observations of the Galactic Globular Cluster tary nebulae, works in the field of radiation transfer theory, NGC 6397. They derive accurate color-magnitude diagrams are the main scientific achievements of the Byurakan 2 ANNUAL REPORT ISAAC NEWTON INSTITUTE OF CHILE 3 astronomers. Markarian, Arakelian and Kazarian galaxies are 2.1 Main Scientific Results known to all astronomers working in the field of extragalac- Galactic Astronomy, Mauron, Azzopardi, Gigoyan, and tic astronomy. Among the most well-known astronomers Kendall ͑A&A 418, 77, 2004͒ have undertaken a new search who have worked at BAO are V.A. Ambartsumian, B.E. for cool N-type carbon ͑C͒ stars in the halo of our Galaxy Markarian, G.A. Gurzadian, M.A. Arakelian, L.V. Mirzoyan, based on the 2MASS survey. Candidates were first selected E.Ye. Khachikian, and E.S. Parsamian. V.A. Ambartsumian in the 2MASS Second Incremental Release database with has been the IAU President ͑1961-64͒, IAU Vice-President JHKs colors typical of red AGB C stars and Ks Ͻ 13, and ͑1948-55͒, twice the ICSU President ͑1968-72͒, he was the subsequently checked through medium resolution slit spec- President of the Armenian Academy of Sciences during troscopy. We discovered 27 new C stars plus one known 1947-1993 and the Director of BAO during 1946-1988. previously and two similar objects in the Fornax and Sculp- At present, BAO has some 70 researchers, including 9 tor dwarf galaxies. They determine and discuss the properties Doctors of Science and 38 Candidates of Science ͑Ph.D.͒. of the sample, including optical and near-infrared colors, ra- Many are members of IAU, EAS, EAAS ͑Euroasian Astron. dial velocities, as well as Ha emission and variability that are Soc.͒, and other international societies and organizations. frequent, all these characteristics being compatible with an Since the beginning of 2004, the Director is Haik Harutyu- AGB C-type classification. They adopt the view that all ob- nian. There are 3 scientific divisions and 12 research groups. jects are of AGB type, i.e. luminous and distant. Because the A number of associates teach at the Yerevan State University stream of Sagittarius dwarf galaxy is known to be the domi- ͑YSU͒, including 5 INI Armenian Branch members. nant source of luminous C stars in the halo, the authors chose The main fields of scientific activity at BAO are: to determine distances for the sample by scaling them on the • Search and multiwavelength studies of AGN and star- 26 known AGB C stars of the Sgr galaxy itself, which are burst galaxies, found to be, in the Ks-band, 0.5 mag less luminous than the • Infrared and radio galaxies, average LMC C stars for a given J-Ks color. The obtained distances of the halo stars range from 8 to 80 kpc from the • Young stellar objects and their environments, Sun. The examination of position and radial velocities shows • Physics of nebulae, that about half belong to the Sgr stream. The authors suggest • Variable stars, that numerous AGB C stars remain to be discovered in the • Clusters of galaxies, halo. Long term Ks-band monitoring would be of great value • Observational cosmology, to ascertain distance estimates through the period-luminosity • Theory of compact cosmic objects, relation, because a large fraction of their sample is probably made of Mira variables. The work is based on observations • Radiative transfer theory, made at the European Southern Observatory ͑ESO͒, Chile • Solar activity. and at the Haute Provence Observatory ͑OHP, France͒, to- The traditional methods for investigations are surveys, gether with data from the 2MASS project. spectroscopic, photometric and polarimetric observations, Movsessian, Magakian, Boulesteix, and Amram ͑A&A statistics, and direct and inverse theoretical problems. The 413, 203, 2004͒ have studied various manifestations of the Byurakan astronomers collaborate with scientists from outflow connected to the cometary nebula GM 3-12 ͑RNO France, Germany, Italy, UK, Spain, Russia, USA, Mexico, 124͒. The results of imaging and scanning Fabry-Perot inter- Japan, China, India, Chile, and other countries. The funding ferometry of GM 3-12 and Herbig-Haro object HH 376A are of science in Armenia is at very low level; however, the presented. The nebula is cone-shaped with the star IRAS Byurakan astronomers work actively due to the international 20359ϩ6745 at the apex, showing straight walls and two collaboration and grants, and valuable contribution in sci- probable helical arms.
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