Osservatorio Astronomico di Bologna Annual Report 1999 Osservatorio Astronomico di Bologna Via Ranzani n. 1, I - 40127 Bologna, ITALY Tel. +39-051-2095701 ; Fax. +39-051-2095700 http://www.bo.astro.it/ . Presentation The Osservatorio Astronomico di Bologna is one of the twelve Ital- ian Observatories, operating under the supervision of the Ministry for University and Scientific and Technological Research. The Ministry provides most of the financial resources which make our activity pos- sible. This Report provides an overview of the our scientific research, covering a wide range of topics in astronomy such as : galactic and stellar evolution studies and their cosmological im- • plication study of the structure, evolution and distribution of galaxies, • clusters and AGN and their contribution to the cosmological background numerical studies and software developments in the fields of the • turbulence simulations and deconvolution techniques management and upgrading of the two telescopes in Loiano (152 • and 60 cm) and development of astronomical instruments in the framework of national and international programs. Most of these studies are based on an intensive use of the most advanced instruments available today at all wavelengths. These are carried out in collaboration with many international and national in- stitutes and, locally, with the Universit´adi Bologna, Dipartimento di Astronomia and with the Consiglio Nazionale delle Ricerche (CNR). Moreover, a large fraction of the staff is involved in international long term projects (VIRMOS, ISO-ELAIS, ESO slice project, K20 redshift survey). Finally between the last months of 1998 and the first half of 1999 the Osservatorio Astronomico di Bologna and the Dipartimento di As- tronomia moved to the new building in Via Ranzani 1. The definition of the new logistic for the hardware, the re-wiring of the computer network and the re-installation of all the computers required a strong effort to the computer center staff. This report has been prepared by Paolo Ciliegi, Lucia Pozzetti and Monica Marra, with the collaboration of Michele Bellazzini, Luca Ciotti, Antonio De Blasi, Hans De Ruiter, Roberto Di Luca, Monica Ferrarini, Marco Lolli, Roberto Merighi, Cristian Vignali and Valentina Zitelli. Bruno Marano Staff Director: Bruno Marano • Board of Directors: Bruno Marano, chairman; Luigi Danese, • S.I.S.S.A.; Giorgio Sironi (Un. di Milano); Mauro Pucillo, Oss. Astr. di Trieste; Giancarlo Setti, Un. di Bologna; Gianni Zamora- ni; Nicolo' D'Amico vice-chairman; Luca Ciotti; Vittorio Marre' Brunenghi, Primo Dirigente, M.U.R.S.T.; Anna Maria Como, Dirigente Superiore, Amm. Monopoli di Stato; Franco Tinti Auditors: Pasquale Vilardi (CNEL); Mario Pavone (MURST); • Luciana Tomaselli (MURST) Scientific Staff: Bardelli, Sandro; Bedogni, Roberto; Bellazzini, • Michele; Bonifazi, Angelo; Bragaglia, Angela; Cacciari, Carla; Cappi, Alberto; Ciliegi, Paolo; Ciotti, Luca; Clementini, Gisella; Comastri, Andrea; D'Amico, Nicolo'; Delpino, Federico; D'Ercole, Annibale; De Ruiter, Hans; Federici, Luciana; Ferraro, Francesco; Fusi Pecci, Flavio; Greggio, Laura; Londrillo, Pasquale; Merighi, Roberto; Mignoli, Marco; Origlia, Livia; Parmeggiani, Gianluigi; Pozzetti, Lucia; Sancisi, Renzo; Stanghellini, Letizia; Stirpe, Giovanna; Tosi, Monica; Zamorani, Gianni; Zitelli, Valentina; Zucca, Elena Computer Centre: Di Luca, Roberto; Gatti, Michele; Lolli, Marco; • Madama, Guido; Montegriffo, Paolo; Policastro, Rocco Laboratory: Bregoli, Giovanni; Ciattaglia, Costantino; Inno- • centi, Giancarlo; Marchesini, Alberto; Tinti, Franco Loiano Staff: Bernabei, Stefano; De Blasi, Antonio; Gualandi, • Roberto; Mezzini, Rino; Muzi, Ivo; Salomoni, Paolo; Tessicini, Gianni Administration: Greganti, Andrea; Guizzardi, Clara; Leonardi, • Laura; Mazzone, Filomena; Orlandi, Marco; Papani, Mario; Pic- cioni, Annalia; Venturini, Adele Library: Ferrarini, Monica; Marra, Monica • Reception: Caputo, Silvana; Diodato, Olga; Iuso, Annalisa; Po- • lastri, Tiziana; Ravaglia, Maurizio. Contents 1 Stars and Stellar Populations 1 1.1 The chemical evolution of the Galaxy . 3 1.1.1 Models . 3 1.1.2 Open clusters as tracers of the evolution of the abundance gradients. 4 1.1.3 Applications to Cosmology . 5 1.2 Galactic Globular Clusters . 6 1.2.1 Tests of the theoretical stellar models . 6 1.2.2 Dynamics and stellar evolution . 8 1.2.3 Cosmological applications . 9 1.2.4 The star formation and metal enrichment his- tory of ! Cen. 12 1.3 Globular Clusters Systems . 13 1.3.1 Optical and NIR imaging of Magellanic Cloud clusters. 13 1.3.2 The Globular Cluster System of the Andromeda galaxy . 14 1.3.3 Globular Cluster Systems in external galaxies . 16 1.4 Nearby Galaxies . 17 1.4.1 Star formation histories in dwarf irregular galaxies 17 1.4.2 Blue Compact Dwarfs . 18 1.4.3 Dwarf Spheroidal Galaxies . 19 1.4.4 The Andromeda galaxy . 21 1.5 RR Lyrae variable stars . 21 1.5.1 Distance to the LMC . 22 1.5.2 Applications of the BW method . 23 1.5.3 RR Lyrae in LG galaxies and in globulars . 24 1.5.4 Anomalous RR Lyrae . 25 1.5.5 Development of specific software . 25 1.6 Eclipsing binaries . 26 1.7 Planetary Nebulae . 26 1.7.1 Morphology of Galactic Planetary Nebulae . 28 1.7.2 Post-Asymptotic Giant Branch Evolution . 29 1.8 Pulsars . 29 1.8.1 Parkes Multibeam Pulsar Survey . 30 1.8.2 Search of the Globular Cluster system for mil- lisecond pulsars . 30 1.8.3 Millisecond Pulsars Survey at the Northern Cross 30 i 1.9 Integrated Light of Early Type Systems . 31 1.9.1 Elliptical Galaxies . 31 1.9.2 Dwarf Elliptical Galaxies . 32 2 Extragalactic Astronomy and Cosmology 33 2.1 Structure and evolution of galaxies . 35 2.1.1 Theoretical studies and numerical simulations . 35 2.1.2 Neutral hydrogen studies . 37 2.2 Active galactic nuclei . 40 2.2.1 Optical studies . 40 2.2.2 Near-IR studies . 41 2.2.3 X-ray studies . 41 2.2.4 Radio galaxies . 43 2.3 Surveys and Observational Cosmology . 43 2.3.1 VIRMOS . 44 2.3.2 K20 Redshift Survey . 45 2.3.3 The ESO slice project . 45 2.3.4 Bright galaxies from WENSS . 47 2.3.5 The HELLAS Survey . 47 2.3.6 The ELAIS Survey . 48 2.3.7 FIRBACK . 49 2.3.8 Radio observation of the ESP Survey . 50 2.3.9 Deep Extragalactic Surveys in the Marano Field 50 2.3.10 Radio Observations in the Lockman Hole . 52 2.3.11 Extremely red objects . 53 2.3.12 Photometric redshifts . 53 2.3.13 The Extragalactic background light . 54 2.4 Galaxy clusters and large-scale structure . 54 2.4.1 The Shapley Concentration . 54 2.4.2 The distribution of galaxies as a function of lu- minosity . 55 2.4.3 Galaxy systems at z 0:5 . 56 2.4.4 Galaxy clusters and large-scale∼ structure . 56 3 Numerical studies and software development 59 3.1 Turbulence . 61 3.2 StarFinder . 61 ii 4 Instruments and Techniques 63 4.1 Light Pollution . 65 4.2 Treatment of astronomical mirrors . 65 4.3 TNG . 66 4.4 The VLT Project . 66 4.5 The Pulsar Project . 67 4.6 OmegaCAM project . 67 5 Loiano observing site 69 5.1 Working and use of 152 cm . 72 6 Computer center and computer network 77 6.1 Introduction . 79 6.2 Computer center improvements . 79 6.3 Improvements in the local network . 81 6.4 Improvements in the geographic network . 82 6.4.1 Computer networks . 82 6.4.2 Web applications . 83 6.5 Improvements in the accessory services . 83 6.6 Loiano station . 84 6.7 Routine activities . 84 6.8 Other activities . 85 7 Library 87 8 Informative and educational activities 91 8.1 Col Favore del Buio . 93 8.2 Con il laser tra le stelle . 94 8.3 Leggere il cielo . 94 8.4 Sun Eclipse 1999 . 95 8.5 IperAstro . 95 8.6 Edgar Allan Poe . 95 9 List of Publications 97 10 Observing Campaigns 123 11 Position held in working groups and science policy com- mittees 131 12 Organization of Workshops and Schools 132 iii 13 PhD theses at the Bologna Observatory 133 14 Post-Doctoral and Post-Laurea fellowship 133 iv 1 Stars and Stellar Populations 1 The Globular Cluster NGC 6093 with the Hubble Space Telescope. This high-resolution image was created from 2 separate pointings of HST. One WFPC2 data set was obtained by Ferraro, F.R.(OAB) B. Paltrinieri, R.T. Rood, B. Dorman who study blue stragglers. The other data set was acquired by M. Shara, D. Zurek and L. Drissen to search for dwarf novae. (Image Credit: Hubble Heritage Team AURA/STScI/NASA) 2 Involved people at OAB: Scientific staff: M. Bellazzini, A. Bonifazi, A. Bragaglia, C. Cac- • ciari, G. Clementini, N. D'Amico, L. Federici, F.R. Ferraro, F. Fusi Pecci, L. Greggio, L. Origlia, L. Stanghellini, M. Tosi; Technical staff: M. Lolli, P. Montegriffo; • Fellows: L. Di Fabrizio, M. Messineo, A. Possenti. • The evolution of stars and stellar systems under many points of view is an active research field of the OAB since its foundation. The interests range from evolution of galaxies to galactic and extragalactic globular clusters systems, from binaries to variable stars, from pulsars to LMXBs, covering the whole range of astronomical wavelengths. The present short description of the activity in the year 1999 has been organized in a few main sections to provide a very general view: 1. The chemical evolution of the Galaxy, 2. Galactic Globular clusters, 3. Globular Clusters Systems, 4. Nearby Galaxies, 5. RR Lyrae Variable stars, 6. Eclipsing binaries, 7. Planetary Nebulae, 8. Pulsars, 9. Integrated Light of Early Type Systems. 1.1 The chemical evolution of the Galaxy 1.1.1 Models Involved people at OAB: Tosi. Models of Galactic chemical evolution are nowadays able to repro- duce the vast majority of the observed characteristics of our Galaxy and the models computed by our group are among the most successful ones.