VST-SCIENZA:  ELENCO CONTRIBUTI

In questa pagina sono elencati gli abstract dei contributi presentati nel meeting VST scienza, ordinati per sessioni diverse seguendo il programma del convegno.


SESSIONE INTRODUTTIVA

Massimo Capaccioli:  "Introduzione al meeting"

Giorgio Sedmak: "Stato e prestazioni del telescopio VST"
Vengono presentati lo stato, la schedula futura e le prestazioni calcolate del telescopio VST alla chiusura della Final Design Review di Settembre 2000.

Dario Mancini:  "VST project strategy"

Enrico Cappellaro: "Status of the Omegacam project"
 

SESSIONE 1.  Wide Field Imaging: Riduzione e Analisi dati, Data Base, Data Mining

Roberto Morbidelli:  "Dal plate al Catalogo: l'esperienza GSC2 - COMPASS db"

Emanuela Pompei:  "The Wide Field Imager at the 2.2 m ESO/MPG telescope in La Silla Observatory"
I will briefly describe the characteristics of the Wide Field Imager (hereafter WFI) detector mounted at the ESO/MPG 2.2 m telescope (LaSilla Observatory) since the end of 1998. I will discuss the observing modes, the calibrations and the data reduction strategy and I will compare the WFI with the other wide field cameras available in the world. Taking into account that the major goal of the workshop was to discuss strategies and ideas for the upcoming VST and OmegaCam, this work will focus on the expertise gained while supporting the instrument and with the data reduction and analysis.

Juan Alcalà:  "The Capodimonte Deep Field: a first step towards VST"
The Capodimonte Deep Field (CDF) is a multi-colour imaging survey project conducted using the ESO Wide Field Imager (WFI) attached to the 2.2~m telescope at la Silla, Chile. As a pilot OAC project, the CDF not only aims at providing a large photometric database for deep extragalactic studies (with important by-products in galactic and planetary science), but also at gathering experience in large mosaic data handling, in view of the arrival of the VST. The CDF data reduction, photometric calibrations and criteria for the catalogue extraction are presented. Issues related to the characterisation of the ESO WFI are also discussed.

Giuseppe Longo:  "Data mining in VST database: search for rare or unexpected phenomena"
The availability of very large database poses unprecedented problems in data analysis. The science which can be extracted from VST archives will largely depend on the availability of powerful tool for data fusion and data mining. In this talk we shall emphasise some types of research which these new tools can allow in both the space and time domains and shall outline some requirements which must be taken in to account by any survey work in order to ensure a proper scientific exploitation of the databases.

Patrizia Caraveo (IFC, Milano):  "Il VST vs INTEGRAL, AGILE, SWIFT e GLAST"
High energy space astronomy will blossom in the near future thanks to missions such as INTEGRAL (ESA mission, launch date: april 2002), AGILE (ASI mission, launch date: March 2003), SWIFT (NASA mission with Italian participation, launch date: Sept. 2003) and GLAST (NASA mission with Italian participation, launch date : 2006).  Owing to their large field of views, all missions will discover hundreds of variable sources and thousands of serendipitous
objects in need of identification. Since the sources will be positioned with  a typical accuracy of several arcmins, large field optical facilities, such the VST,  will be instrumental to search for the counterparts of such sources.  While the study of the variable sources will require a fast reaction (almost immediate for the study of the optical counterparts of gamma-ray bursts), the search for counterparts of the steady, serendipitous sources can be done off-line.

SESSIONE 2:  Universo ad alto redshift

Andrea Grazian: "Survey of QSOs at high redshift with VST: going deep into the epoch of QSO formation"
QSO clustering and LF at high-z are important astrophysical and cosmological tools. Distant QSOs mark the formation of primordial structures and provide links with the evolution of normal galaxies. A deep and wide multicolor database has been obtained with WFI  to select high-z (z>4.5) QSOs candidates: strategy, science goals of the survey and preliminary results will be discussed.  We propose to push this survey of QSOs at higher redshift (z>5) with VST, given its large FOV and the enhanced sensitivity in the red bands, necessary to find distant and rare objects in more effective way than WFI. A detailed statistical study of the QSO population provides information on the early universe both directly, tracing the Dark Matter Halos and  indirectly trough the IGM absorption lines.

Adriano Fontana:  "Studying high redshift galaxies with deep multicolor surveys: the role of wide field instruments"
My talk will be focused on multicolor imaging surveys, that have proved to be a powerful tool to identify and study galaxy evolution at high redshift. Over the last years, we have extensively used deep imaging data obtained with HST, NTT and VLT to assess the reliability of this technique and to study the most fundamental properties of high redshift galaxies. I will discuss in the talk how the new planned wide field facilities, and in particular the VST, can be efficiently used to provide a true quantum leap in our knowledge of the physical properties of high redshift galaxies.

Alma Marino:  "Misura dei parametri cosmologici tramite conteggi di galassie"
Theory shows that the density (number counts) of background galaxies around a cluster is affected by the  gravitational effects of the cluster and undergoes two opposite effects: an increase in density due to the fact that the gravitational amplification makes detectable more objects, and a decrease, due to the deviation of light far away from the cluster center.  These effects are observable only if the slope of the background galaxy counts differs from 0.4. In the apparent magnitude range planned for the VST-OAC survey, this condition is matched in both the R and V bands.  The proposed survey will cover at least 50 nearby clusters having mass luminosity profiles derived from the XMM X-ray data. These data will allow to
better model the properties of the lensing clusters and to better constrain the lensing phenomena, thus leading to a higher accuracy in the estimate of the cosmological parameters.

SESSIONE 3:  Universo a redshift intermedio

Giuseppe Altavilla:  "Supenova  rate at intermediate redshifts"
We present a proposal for a supernova search at intermediate redshifts (z < 0.5) aimed to estimate supernova rates.  We are interested in both type I and type II SNe;  because of the link between SNe and the stellar population, these estimates can be used to constrain the SFR in intermediate redshift galaxies. In particular, type II SNe are good tracers of the instantaneous SFR while type I SNe are indicative of the average SFR in the galaxy history. There is not need to stress the interest for Type Ia SNe as probe of the cosmological parameters. The possible synergies with other intermediate redshifts researches are highlighted.

Daniela Bettoni:  "A photometric wide field survey of low-z clusters: Defining the local reference sample for distant clusters studies"
Cluster of galaxies are the largest , yet well defined, known entities in the universe. The identification of their properties and content could led to use them as tracers of cosmic evolution since they can be detected at large distances. When confronted with such kind of analysis one realizes that we still lack a well defined local reference, that would define the zero point in those studies, to which refer the properties of more distant clusters. Our aim is to built such a local reference. We want to carry out a wide field photometric survey of an essentially complete, X-ray flux-limited sample of clusters in the redshift range 0.04<z<0.07. This will represent the first systematic set of data for the clusters in the nearby universe and will became the local reference sample for distant clusters studies.

Stefano Andreon:  "The VST survey of the XMM-LSS field"
The XMM-LSS field (64 degrees squared) will be the most observed area of the sky in the next few years. On this field are planned, just for citing observations on guaranteed time, optical observations (with Omegacam@VST, Megacam@CFHT, CFH12K@CFHT, Mosaic@CTIO, WFI@2.2), observations in the near-infrared with WFIRC and in the far infrared with SIRFT, X and UV observations (with XMM-Newton), radio and millimetric observations, spectroscopic observations (with Vimos@VLT, Gemini and others 11 instruments+telescopes). In this talk the aims of this survey and the role of VST (~60 guaranteed nights are allocated to the project) are introduced.
For the VST survey look at: http://www.na.astro.it/~andreon/XMM /
For the XMM-LSS collaboration look at: http://vela.astro.ulg.ac.be/themes/spatial/xmm/LSS/

Loretta Gregorini:  "Faint Radio Surveys and Wide Field Photometry"

Filippo Mannucci:  "Looking for the missing barionic mass"
Evidence for hot gaseous filaments has been suggested by ROSAT maps in the Lockman Hole on the scale of about 1 degree. These filamentary structures could be the first clear evidence for the clumping of gas at z~0.5 expected by theoretical models and which should be the main reservoir of baryons in the local Universe. If this interpretation is correct the X-ray filamentary structures should correlate with the density of galaxies. Large field observations are needed to test this hypothesis: the projected density of galaxies and their redshift distribution can be derived from multiwavelentgth optical and near-IR photometry using the technique of photometric redshift. Some pilot observations have already been obtained.

Dario Trevese:  "A Survey for `Variable Galaxies'"
Quasar surveys based on non-stellar colors are intrinsically limited to point-like sources to avoid the contamination by galaxies. It has been shown that suitable variability surveys are able to select virtually all the objects which can be selected through color techniques. A variability survey for extended objects can select QSOs and AGN which are lost by color techniques. They populate a region of the luminosity-redshift plane of special interest for QSO/QGN evolution and provide interesting samples for the study of host galaxies. We report the result of the photographyc survey conducted with the 4 m telescope of the Kitt Peak Observatory and suggest the possibility of a similar survey with VST.

Vincenzo Antonuccio-Delogu:  "A photometric survey of nearby Voids"
 

SESSIONE 4:  Universo vicino

Piero Rafanelli:  "Multiwavelength properties of the environment of Narrow-Line Seyfert 1"

Magda Arnaboldi:  "Narrow band imaging surveys with the VLT: Extragalactic Planetary Nebulae and the deep emission line Universe"
I will present the results of a recent imaging survey done with a narrow band filter in the Virgo cluster to identify intracluster planetary nebuale. This imaging survey has proven itself to be a mine for probing the large scale structures at redshift 3.13 and a test for starburst activity at redshift 0.34. The use ofan  automatic detection algorithm like sextractor allow us to perform a screening of the different candidates based on their morphology and colors. Tests based on preliminary spectroscopic follow-up will be presented.

Massimo Della Valle (Arcetri Observatory, Florence); R. Gilmozzi (ESO):  "Observations of extragalactic novae with VST"
Surveys of novae in extragalactic systems have not been popular among astronomers (remarkable exceptions are M31 and, marginally, M33). The major reason for this is probably the unpredictable nature of these events, which make nova surveys considerably (telescope) time consuming. As a consequence, very little is known about the nova populations in extragalactic systems. In particular, almost nothing is known about the properties of nova explosions in different metallicity environments. The large field of the VST can improve the efficiency of nova discoveries in nearby galaxies by almost an order of magnitude, as compared to previous surveys with 2-m class telescopes.  A search for extragalactic novae during the nebular stage, when nova light is mainly emitted in Halpha or [O III], can derive as simple by-product of the `narrow band imaging surveys' proposed during this meeting by Arnaboldi (near Universe) and Magrini (Local Group). To discriminate PNe from Novae we need a second epoch, to be obtained about 1 yr apart.

Enzo Brocato:  "A chance: to derive Surface brightness Fluctuation measurements by using images from VST surveys"
The Surface Brightness Fluctuation (SBF) provides a powerfull method (Tonry & Schneider 1988) to determine extragalactic distance of galaxies. We have defined and tested a new and independent theoretical calibration of absolute SBF magnitude for UBVRIJHK and HST filters. We are investigating the possibility of using the high quality images obtained during the 'normal' survey work of VST to derive SBF measurements of suitable galaxies following in the observed fields. For such a galaxies we expect to derive distances by adopting our SBF calibration. Due to the large number of SBF measurements of relatively nearby galaxies we also expect to investigate in detail the reliability of our calibration (for example metallicity effects).

SESSIONE 5:  Gruppo Locale

Francesco R. Ferraro:  "La fotometria a grande campo come strumento per comprendere la formazione e l'evoluzione della Galassia e del sistema locale (il caso di Omega Centauri e la galassia sferoidale Sextans)"
Una delle più naturali applicazioni della fotometria a grande campo alla astronomia galattica è lo studio dettagliato di sistemi stellari vicini (come gli ammassi globulari)  e/o di bassa brillanza superficiale (le galssie sferoidali). La fotometria a grande campo permette (1) di ottenere campioni ricchi e completi in grado di evidenziare popolazioni rare e/o sequenze poco popolate (2) di comprendere la struttura spaziale dei sistemi stellari e delle singole popolazioni al loro interno. Questo tipo di studio permette di  comprendere la formazione e  l'evoluzione della galassia e delle galassie del gruppo locale. A titolo di esempio sono  presentati alcuni risultati ottenuti con la camera a grande campo dell'ESO (WFI) nell'ammasso omega centauri (l'ammasso più popoloso del sistema di ammassi globulari galattici) e della galassia sferoidale Sextans.

Marcella Marconi:  "Pulsating variable stars with VST"
In this talk the use of VST for the study of Classical Cepheids and RR Lyrae pulsating stars is discussed. Objects belonging to different galactic and extragalactic environments are considered, with particular attention to the issues of the cosmic distance scale and stellar population properties.

Enrico V. Held:  "The star formation histories and spatially resolved stellar populations of Local Group galaxies"
L'introduzione dei mosaici di CCD ha aperto prospettive interamente nuove nello studio delle galassie risolte del Gruppo Locale. Date le grandi dimensioni angolari dei galassie nane vicine, in particolare dei satelliti della Via Lattea, solo l'imaging a grande campo può consentire una conoscenza adeguata delle popolazioni stellari che le compongono, formate nel corso di successive generazioni. Il telescopio VST permetterà di ampliare lo studio già iniziato dal nostro gruppo con dati WFI@2.2m ESO, grazie agli strumenti di riduzione avanzati da noi sviluppati nell'ambito del progetto nazionale COFIN98.

Laura Magrini:  "A comprehensive search of Planetary Nebulae and related emission line objects in the local Group with VLT"
Extragalactic planetary nebulae (PNe) are relevant to various astrophysical subjects including the dynamics of disk population stars and chemical gradients of intermediate age stars in spiral galaxies. The present status of knowledge of PNe in the Local Group galaxies has been summarized by Jacoby (cf. 1997, in IAU Symp. N. 180, p.448). We have contributed to the field with the discovery of many new PNe in M 33 (Magrini et al., 2000 ; A&A 355, 713). Perspective goals of the proposed search will be discussed.

Mauro D'Onofrio:  "Why study extended luminous halos of nearby galaxies with VST"
 

SESSIONE 6:  Struttura della Galassia

Vittorio Castellani:  "Faint stars in the galactic halo"

Sergio Ortolani:  "Survey di ammassi stellari in direzione del bulge galattico"
Si propone una mappatura del bulge galattico a latitudini comprese tra +/-2 gradi e longitudine +/- 7 gradi, nelle bande I e Gunn z, per la ricerca di ammassi stellari. Nella fascia proposta pochi ammassi stellari sono stati finora scoperti con le tradizionali analisi delle lastre fotografiche a grande campo a causa dell'elevata estinzione e (Barbuy, Bica, Ortolani, AA, 1998, 333, p. 118, Fig. 1). Le recenti survey a grande campo nell'infrarosso sono abbastanza profonde e mostrano numerosi potenziali candidati, ma i risultati sono incerti perchè non offrono la risoluzione sufficiente per la corretta identificazione. VST offre una buona risoluzione e una sufficiente sensibilità.

Roberto Silvotti:  "Disk and halo White Dwarfs"
The White Dwarf Luminosity Function (WDLF) contains crucial informations on the genesis of our galaxy: age of the galactic disk (+ halo), IMF, stellar formation rate. Moreover the recent results of the MACHO+EROS experiments indicate that the microlensing events are mainly produced by halo objects with an average mass of ~0.5 Msun, suggesting that part of the dark matter could be formed by halo WDs. A medium deep survey (V<25) at high galactic latitude will allow to detect all the disk WDs in the field, i.e. about 10 WDs/sq.deg. at l=90 deg, including the coolest and oldest ones at Teff ~ 4000 K, which are the most important for the disk LF.  Moreover we expect to find a few halo WDs, which would be of great interest as the halo WDLF is still almost totally unknown.

SESSIONE 7:  Sistema Solare

Elena Mazzotta Epifani:  "VST per il Sistema Solare:studio delle proprieta' di Kuiper Belt Objects e di Centauri"
Oltre il confine stabilito dall?orbita dell?ultimo dei pianeti giganti, Nettuno, è presente una densa fascia di corpi in orbita tra 30 e 50 AU, denominata Kuiper Belt (KB). Fino ad oggi, sono stati scoperti solo poco più di 300 oggetti appartenenti a questa famiglia, considerata composta dagli ultimi resti sopravvissuti, praticamente intatti, dall?epoca della formazione del Sistema Solare. Constraints osservazionali evidenziano che Kuiper Belt Objects (KBOs) più brillanti della magnitudine mR=20 sono relativamente rari, e, visto che finora una porzione relativamente piccola del cielo è stata scandagliata per la loro ricerca, si rendono necessarie osservazioni tipo survey con grande campo. Inoltre, per rivelare i KBOs più deboli, e contribuire così alla definizione della funzione cumulativa di luminosità della KB, essenziale per definire le distribuzioni di dimensioni e distanze nelle regioni più esterne del Sistema Solare, sono necessarie osservazioni profonde e ripetute nel tempo. Dinamicamente distinti, ma legati alla KB da considerazioni di natura evolutiva, sono i Centauri, che si muovono su orbite abbastanza instabili con semiassi maggiori compresi tra quelli di Giove e Nettuno. Ancora molto poco si sa sui membri di questa famiglia: essi vengono definiti transizionali, probabilmente in evoluzione dalla KB (Trans-nettuniana) alla fase cometaria, per effetto delle perturbazioni gravitazionali dei pianeti maggiori. Lo studio delle proprietà di questi oggetti, grazie ad osservazioni di fotometria in banda larga dall?U all?I per determinarne i colori, permetterà di ottenere indicazioni sulla composizione superficiale, sulla forma e sulle dimensioni, sul periodo di rotazione, sull?eventuale presenza di attività di degassamento, in modo da confrontarli con altre classi di oggetti "minori" del nostro Sistema Solare (nuclei cometari, asteroidi...) e indagare sul processo di evoluzione dalla KB alle comete a corto periodo.

Alberto Cellino:  "Using VST to assess the inventory of the Main Belt asteroid population"
 

SESSIONE 8:  Follow-up Spettroscopico

Carla Cacciari:  "Follow-up spectroscopy on wide fields: FLAMES"
With the ESO Call for Proposals of end-September 2001 the high-resolution multi-object spectrograph FLAMES (VLT-UT2) will be made available to the astronomical community. Its technical characteristics and expected performance are briefly reviewed, as well as some of the possible scientific programs.  Critical aspects of the work to be done in preparation for the observations and for data reduction are mentioned.

Gianpaolo Vettolani:  "VIRMOS"
 

SESSIONE 9: Discussione e Organizzazione Gruppi di Lavoro

Giovanni Busarello:  "A VST Survey: Evolution in the Nearby Universe"

Flavio Fusi Pecci:  "VST e VISTA: ottimizzazione indispensabile e possibile"
 


Ultimo aggiornamento: 19 Febbraio 2001