[Todos] IAFE-COLOQUIO: "Super-massive Black Holes Across the Cosmic History" , Martes 23 de agosto 2011, 11hs.

[difusion en iafe.uba.ar]

                    PRÓXIMO COLOQUIO DEL IAFE
                 Instituto de Astronomía y Física del Espacio
                           CONICET-UBA
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          "Super-massive Black Holes Across the Cosmic History"

                             Ezequiel Treister
    Institute for Astronomy http://www.ifa.hawaii.edu/, University of Hawaii
                    Martes 23 de agosto 2011, 11hs.
                         Aula del Edificio IAFE

It is now clear that the formation of the super-massive black hole (mass
greater than a million solar masses) that can be now found in the center
of most massive galaxies is directly connected to the evolution of the
host galaxy. However, the details of this connection are still not well
understood. In order to fully understand galaxy formation we need to know
when in the cosmic history are black holes growing more intensively, in
what type of galaxies this growth is happening and what fraction of these
sources are invisible at most wavelengths due to obscuration.

In this talk, I will review observations of the density of black hole
accretion from the nearby Universe at z~0 to early growth episodes at z~6,
when the Universe was less than a billion years old. This is done by
combining multiwavelength data ranging from infrared to soft gamma rays in
both wide/shallow and narrow/deep surveys. We find that a large fraction
of the black hole growth, ~75%, is obscured, and report evidence for a
strong connection between significant black hole growth episodes and major
galaxy mergers from z~0 to z~3. We then measure from deep
optimally-stacked Chandra X-ray observations the amount of black hole
growth in z=6-8 galaxies (0.7-1 billion years after the Big Bang), and
find that most of this activity is heavily obscured. Prospects for future,
complete, black hole census will be discussed.