 |
It is now well-established
that black holes are an important
feature of our cosmic environment. Stellar-mass black holes number in
the millions in every galaxy; there is now conclusive evidence that
black holes as massive as a billion suns reside at the centers of most
galaxies. Black holes are thought to power the most energetic
phenomena in the Universe from quasars to, perhaps even Gamma-Ray-Bursts.
My research interests focus on studies of black holes encompassing
a wide range of topics in both High Energy Astrophysics and Cosmology.
They include theoretical studies of the interplay between black hole
growth and galaxy formation and investigations of various aspects of
the physics of accretion disks around black holes.
Cosmological simulations of black hole formation: I am currently
involved in developing a new prescription in the context of hydrodynamical simulations of galaxy formation which, together with
star formation and supernovae feedback, follows black hole accretion
and its associated feedback in the center of galaxies. This is a novel
attempt within models of galaxy formation to track self-consistently
the growth of supermassive black holes and the evolution of the galaxy
itself. Galaxy formation and black hole growth are mutually
intertwined processes, requiring joint theoretical modeling to be
meaningfully addressed.
21cm tomography and foregrounds: An exciting future probe of the epoch
of reionization will be 21cm tomography of the neutral hydrogen in the
Intergalactic medium and in gravitationally collapsed systems. I have
been modeling the contaminating foreground radiation to the primary
21 cm radiation due to galaxies which produce radio emission and
free-free emission and extended sources include radio halos and
relics. We are using cosmological simulations and are producing
simulated sky maps for the upcoming Lofar and PAST facilities.
Neutrino transport around black holes and Gamma-Ray Bursts:
In recent years the exciting field of Gamma-Ray Bursts has opened up to the
studies of black hole accretion. Rapid, hyper-Eddington accretion is
likely to power the central engines of Gamma-Ray Bursts. In these
extreme conditions of densities and temperatures the accreting material
is cooled by neutrino emission rather than by radiation. I have been
working on deriving dynamical solutions for neutrino dominated
accretion flows.
Accretion models and X-rays: Accretion of matter onto a black hole is
able to liberate large amounts of its binding energy. By studying the
power output from accretion disks, we are able to probe the deep
gravitational potentials around black holes. Nearby black holes
however, are much less luminous than active galactic nuclei in distant
galaxies. I build models for the emission from nearby black holes
using Chandra Satellite and XMM-Newton observations.
Selected Publications
E. M. Rossi, P. J. Armitage, T. Di Matteo, “Vertical
Structure of Hyper-accreting Disks and Consequences for Gamma-Ray Burst
Out-Flows,” AP&SS 311, 185 (2007)
F. Miniati, S. M. Koushiappas, T. Di Matteo, “Angular
Anisotropies in the Cosmic Gamma-Ray Background as a Probe of Its Origin,”
Astrophys. J., 667, L1-L5 (2007)
D. Sijacki, T. Di Matteo, V. Springel, L. Hernquist, “A
Unified Model for AGN Feedback in Cosmological Simulations of Structure
Formation,” MNRAS, 380, 877 (2007)
I.F. Pelupessy, T. Di Matteo, B. Ciardi, “How Rapidly Do
Supermassive Black Hole “Seeds” Grow at Early Times?” Astrophys. J., 665,
107-119 (2007)
Y. Li et al., “Formation of  Quasars from Hierarchical Galaxy Mergers,” Astrophys. J.,
665, 187 (2007)
Y. Yuan , A. Janiuk, , R. Perna, T. Di Matteo, “Time
Dependent Neutrino Disc in Gamma Ray Bursts Under  -equilibrium,” Astrophys. J., 664, 1011 (2007)
S. Chakrabarti et al., “Feedback-Driven Evolution of the
Far-Infrared Spectral Energy Distributions of Luminous and Ultraluminous
Infrared Galaxies,” Astrophys. J., 658, 840 (2007)
|
