SEMINAR ANNOUNCEMENT-OAT and DAUT SEMINAR-Wedn. October 18, at 3 pm (PLEASE NOTE TIME) at Villa Bazzoni

[Gabriella Schiulaz]

Here follows the announcement of the next OAT-DAUT seminar.
PLEASE NOTE TIME IS  3:00  PM

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                   OATS-DAUT SEMINAR 
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Speaker: Carlotta Gruppioni (INAF/Oss. Astr. Bologna) 

Title: Title: Galaxy and AGN Evolution in the MIR: a combined Spitzer and X-ray view 


Date: Wednesday, October 18th, 2006 

Time: 15:00 (3:00 PM) 

Venue: Villa Bazzoni (address: via Bazzoni, 2)

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Abstract: 
A proper analysis of the evolution of sources emitting in the Mid-Infrared is strongly dependent on their broad-band spectral properties (SEDs) at different redshifts and luminosities and on a reliable classification allowing to disentangle AGN from star-formation activity. The diagnostic diagrams based on the optical line ratios are often ambiguous and/or misleading not allowing a proper separation of the galaxy/AGN populations. Thanks to the combination of deep X-ray and Spitzer a much better census of the hidden AGN activity and dust-obscured star-forming galaxies can be obtained. We show how to take advantage of the new X-ray and Spitzer survey data to constrain galaxy and AGN evolution, revising the results of previous phenomenological models. 
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Future Seminars 

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OATS-DAUT SEMINAR 
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Speaker: Meg Urry (Yale University) 
Title: Supermassive Black Holes in Deep Surveys 

Date: Wednesday, October 25th, 2006 
Time: 11:00 
Venue: Villa Bazzoni 

Abstract: 
In principle, counting Active Galactic Nuclei (AGN) reveals the demographics of supermassive black holes. Optical/UV surveys easily find AGN out to high redshift, and they are numerous in the early Universe (z~2-3); however, if obscuration is important, as suggested by local AGN unification and by the spectrum of the X-ray background, the true number could be much larger. Using the deepest data from the Spitzer, Hubble, and Chandra Observatories, the Great Observatories Origins Deep Survey (GOODS) project reveals evidence for a substantial population of obscured AGN, with which we can explain the integrated X-ray background, the redshift distributions in deep X-ray surveys, and the infrared number counts of AGN. We can also directly estimate the AGN contribution to the extragalactic infrared background. With the larger-area MUSYC survey, we extend this work to higher luminosity AGN, and we report the discovery of new EXOs (Extreme X-ray Objects). Finally, combining all the large, deep, multiwavelength surveys, we find that the fraction of obscured AGN increases with redshift.


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OATS-DAUT SEMINAR 
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Speaker: Massimo Capaccioli (VST Center and INAF-OACN, Napoli) 
Title: The VLT Survey Telescope 

Date: Monday, October 30th, 2006 
Time: 12:00 
Venue: Villa Bazzoni 


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OATS-DAUT SEMINAR 
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Speaker: Matteo Viel (INAF/Oss. Astron. di Trieste) 
Title: Strong MgII systems in quasar and gamma-ray burst spectra 

Date: Wednesday, November 8th, 2006 
Time: 12:00 noon 
Venue: Villa Bazzoni 

Abstract: 
Strong MgII absorption (with equivalent width W>0.3 Angstrom) is produced in patchy gaseous envelopes, up to impact parameters of 80 kpc/h, surrounding galaxies of different morphological types. The incidence of these systems in gamma-ray bursts (GRB) and BL Lac spectra is a few times higher than in quasar (QSO) spectra. I investigate several possible explanations for this effect including: dust obscuration bias, clustering of the absorbers, different beam sizes of the sources, magnification bias of GRBs (i.e. microlensing events), association of the absorbers with the GRB event or the circumburst environment. 

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OATS-DAUT SEMINAR 
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Speaker: Enrico Maria Corsini (Univ. di Padova) 
Title: To Be Announced 

Date: Wednesday, November 15th, 2006 
Time: 12:00 noon 
Venue: Villa Bazzoni 



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OATS-DAUT SEMINAR 
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Speaker: Simone Recchi (INAF/Oss. Astr. Trieste) 

Title: Early evolution of Tidal Dwarf Galaxies 

Date: Wednesday, November 22nd, 2006 
Time: 12:00 noon 
Venue: Villa Bazzoni 

Abstract: 
I will present a progress report of a project concerning the dynamical and chemical evolution of Tidal Dwarf Galaxies. Tidal tails, resulting from the interactions of large galaxies, can create self-gravitating structures which are the seeds of dwarf galaxies. In these galaxies, commonly known as Tidal Dwarf Galaxies , the Dark Matter content is very small, which make them more vulnerable to stellar feedback. Our first step is therefore to understand whether a model galaxy without Dark Matter can sustain the feedback of the ongoing star formation. We present tests of the evolution of models in which star formation efficiency, temperature threshold, initial distribution of gas and infall are varied. We conclude that it is feasible to keep a fraction of gas bound for several hundreds of Myr and that the development of galactic winds does not necessarily stop continuous star formation. At the end of my presentation I will briefly introduce a project concerning the self-enrichment of Globular Clusters. I shall summarize the chemical properties of Globular Clusters, focusing on the hints that some of the stars of the Globular Clusters are polluted by the ejecta released by older stars, probably of intermediate-mass, demonstrating therefore that Globular Clusters are not coeval objects. I will show the strategies and the first results adopted to sharpen our understanding on these issues. 
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For additional information on scheduled OAT seminars see:
http://adlibitum.oats.inaf.it/seminari/


Gabriella Schiulaz
segreteria OAT
Phone: 040-3199241
schiulaz at oats.inaf.it
segreteria at oats.inaf.it