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Thursday, 13 March 2025 |
Video-Recording for any system with MP4-support - Video.mp4 (ca. 399 Mb) |
15:15 – 16:16 |
"The emergence of supermassive black holes in early galaxies"
Speaker:
Prof. Matthew Hayes
(SU)
Abstract:
Cosmological simulations have been
triumphant in predicting the observed
properties of the galaxy population, in
which fundamental components are
connected to the supermassive black holes
(SMBHs) that occupy the centers
of (all?) massive galaxies. Unfortunately,
however, we have no coherent, observationally-verified picture of how these
black holes could have formed,
which raises serious questions about how
to realistically model the Universe.
Estimates of the abundance of active
galactic nuclei, when the Universe was
~10% its current age, allow us to place
the strongest constraints on SMBH
seeding scenarios and also provide the
main focus of this talk.
I will present several new observational
approaches to identifying SMBHs
at early times combining deep observations with the Hubble & James Webb
Space Telescopes (HST+JWST) and bespoke
modeling of galaxy spectra.
Our analysis suggests that formation
scenarios must produce large numbers
of massive seeds (or, less likely,
extremely rapid growth of black holes), and
that signatures of massive black hole
activity are actually abundantly present
already at redshifts of z∼6 (when
the Universe was about 1 Gyr).
I will discuss these results in the
context of SMBH formation and their
connection to early star formation
episodes.
About the Speaker:
Matthew Hayes is a faculty member at the
Department of Astronomy at
Stockholm University. He received his
Master’s degree in Physics from Leeds University, UK, in 1999 and his PhD in
2007 from the Department of Astronomy.
He then spent 3 years as a postdoc at
University of Geneva and 3 more years
in Toulouse. Hayes works on various
aspects of galaxy evolution, and has most recently been concerned with the
first objects to form in the Universe:
early galaxy and black hole formation, as
well as the growth of these with time.