Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.arcetri.astro.it/~marconi/Home_Page/Research/Entries/2010/11/2_Attivita_di_ricerca_su_galassie_e_nuclei_attivi_files/marconi.pdf Дата изменения: Tue Nov 2 18:42:55 2010 Дата индексирования: Wed Feb 6 17:50:21 2013 Кодировка: Поисковые слова: virgo cluster

Normal and active galaxies and their cosmological evolution
A. Marconi, A. Gnerucci, E. Nardini, P. Pietrini, M. Sirigu, R. Valiante Dipartimento di Fisica e Astronomia, Universitґ di Firenze a G. Cresci, L. Hunt, F. Mannucci, G. Risaliti, M. Salvati, E. Sani, R. Schneider, G. Torricelli INAF-Osservatorio Astrofisico di Arcetri R. Maiolino INAF-Osservatorio Astronomico di Roma May 31, 2010

One of the fundamental open questions of modern astrophysics is understanding the physical processes that transformed the nearly homogeneous primordial medium into the present-day universe, characterized by complex structures such as galaxies and clusters of galaxies. In the currently favored cosmology, CDM, the formation of dark matter structures can be simply understood as interactions solely through gravitational forces: small dark matter haloes form first and then merge together to build up larger ones. But the formation of baryonic structures in general, and of galaxies in particular, is much more complex because of the presence of electromagnetic interactions characterizing the physics of baryons. Understanding how galaxies formed and how they become the complex systems we observe today is therefore a ma jor theoretical and observational effort. There is compelling observational evidence of an intimate link between the assembly of galaxies and the growth of supermassive black holes. Most luminous nearby galaxies host a massive black hole (BH) in their nuclei and its mass (MBH 106 - 1011 M ) is tightly correlated with the mass of the host spheroid. This connection has given rise to the term "co-evolution" to indicate that, in some unknown way, galaxies and BHs grow and evolve together. The gravitational sphere of influence of a BH is but a tiny part of the whole galaxy; thus for co-evolution to occur, a process other than 1


gravitational interaction must be at work. It is believed that such a process could be the feedback from the Active Galactic Nucleus (AGN; a BH accreting matter and radiating with large luminosities, LAGN 109 - 1015 L ) onto the host galaxy. AGN feedback over cosmic times reconciles previous inabilities of galaxy formation and evolution models to reproduce the colors of galaxies and their luminosity function. Thus it appears that AGN and their host galaxies are closely connected, and their interplay governs galaxy evolution. Our research activities are developed within this framework of galaxy formation and evolution and are related to: · the synthesis of elements (metals) and dust in galaxies during cosmic epochs; the cosmological evolution of the mass-metallicity relation in galaxies; the cosmic star formation history; · the cosmological evolution of supermassive black holes, their relations with the host galaxy and AGN activity; · high energy physical processes in AGN and the structure of matter surrounding the BH. For our researched, developed both with an observational and theoretical approach we make use of the most recent observatories, like the Very Large Telescope (VLT) of the European Southern Observatory (ESO), the Hubble Space Telescope (HST), the Spitzer and Herschel Space Telescopes, the Chandra and XMM-Newton X-ray satellites, all of NASA and ESA (European Space Agency). Our researches will make use of the large observatories (each pro ject is > 1 GEuro) which are foreseen for the near future: the Atacama Large Mm Array (ALMA), the European Extremely Large Telescope (E-ELT) and the James Webb Space Telescope (JWST), among the others. In the 2007-2009 period we have been funded through PRIN pro jects by MiUR and INAF (Istituto Nazionale di AstroFisica) and by ASI (Agenzia Spaziale Italiana). As of April 2010, our publication record in the 2001-2010 p erio d consists in 253 refereed pap ers in international journals, with a total of 7150 citations (source ISIS). Each of our articles has therefore b een cited 28.3 times on average. Our global H-index is 43.

2