Hydrogen Self Shielding in a Quasar Proximity Zone (2009)
Altay, Gabriel, Croft, Rupert A. C., Di Matteo, Tiziana
We calculate the distribution of HI within 750 proper kpc/h of a quasar, Lbol = 1.62e13 Lsun, powered by an SMBH, Mbh = 4.47e8 Msun, at z = 3. Our numerical model includes a cosmological hydrodynamic...
Faint-end Quasar Luminosity Functions from Cosmological Hydrodynamic Simulations (2009)
DeGraf, Colin, Di Matteo, Tiziana, Springel, Volker
We investigate the predictions for the faint-end quasar luminosity function (QLF) and its evolution using fully cosmological hydrodynamic simulations which self-consistently follow star formation,...
Lyalpha versus X-ray heating in the high-z IGM (2009)
Ciardi, Benedetta, Salvaterra, Ruben, Di Matteo, Tiziana
In this paper we examine the effect of X-ray and Lyalpha photons on the intergalactic medium temperature. We calculate the photon production from a population of stars and micro-quasars in a set of...
The Fundamental Plane of Accretion Onto Black Holes with Dynamical Masses (2009)
Gultekin, Kayhan, Cackett, Edward M., Miller, Jon M., Di Matteo, Tiziana, Markoff, Sera, Richstone, Douglas O.
Black hole accretion and jet production are areas of intensive study in astrophysics. Recent work has found a relation between radio luminosity, X-ray luminosity, and black hole mass. With the...
Simulations of the Sunyaev-Zeldovich Effect from Quasars (2008)
Chatterjee, Suchetana, Di Matteo, Tiziana, Kosowsky, Arthur, Pelupessy, Inti
Quasar feedback has most likely a substantial but only partially understood impact on the formation of structure in the universe. A potential direct probe of this feedback mechanism is the...
Supermassive Black Holes and Their Environments (2008)
Colberg, Joerg M., Di Matteo, Tiziana
We make use of the first high--resolution hydrodynamic simulations of structure formation which self-consistently follows the build up of supermassive black holes introduced in Di Matteo et al....
Croft, Rupert A. C., Di Matteo, Tiziana, Springel, Volker, Hernquist, Lars
We explore galaxy properties and their link with environment and clustering using a population of ~1000 galaxies formed in a high resolution hydrodynamic simulation of the Lambda CDM cosmology. At...
Direct cosmological simulations of the growth of black holes and galaxies (2008)
Di Matteo, Tiziana, Colberg, Jörg, Springel, Volker, Hernquist, Lars, Sijacki, Debora
Effects of Quasar Feedback in Galaxy Groups (2007)
Bhattacharya, Suman, Di Matteo, Tiziana, Kosowsky, Arthur
We study the effect of quasar feedback on distributions of baryons and properties of intracluster medium in galaxy groups using high-resolution numerical simulations. We use the entropy-conserving...
The Role of Galactic Winds on Molecular Gas Emission from Galaxy Mergers (2007)
Narayanan, Desika, Cox, T. J., Kelly, Brandon, Dave, Romeel, Hernquist, Lars, Di Matteo, Tiziana, ...
We assess the impact of starburst and AGN feedback-driven winds on the CO emission from galaxy mergers, and, in particular, search for signatures of these winds in the simulated CO morphologies and...
The Nature of CO Emission From z~6 Quasars (2007)
Narayanan, Desika, Li, Yuexing, Cox, Thomas J., Hernquist, Lars, Hopkins, Philip, Chakrabarti, Sukanya, ...
We investigate the nature of CO emission from z~6 quasars by combining non-LTE radiative transfer calculations with merger-driven models of z~6 quasar formation that arise naturally in LCDM...
A unified model for AGN feedback in cosmological simulations of structure formation (2007)
Sijacki, Debora, Springel, Volker, Di Matteo, Tiziana, Hernquist, Lars
We discuss a numerical model for black hole growth and its associated feedback processes that for the first time allows cosmological simulations of structure formation to self-consistently follow the...
Direct cosmological simulations of the growth of black holes and galaxies (2007)
Di Matteo, Tiziana, Colberg, Joerg, Springel, Volker, Hernquist, Lars, Sijacki, Debora
We investigate the coupled formation and evolution of galaxies and their embedded supermassive black holes using state-of-the-art hydrodynamic simulations of cosmological structure formation. For the...
Instabilities in the time-dependent neutrino disc in Gamma-Ray Bursts (2007)
Janiuk, Agnieszka, Yuan, Ye-Fei, Perna, Rosalba, Di Matteo, Tiziana
We investigate the properties and evolution of accretion tori formed after the coalescence of two compact objects. At these extreme densities and temperatures, the accreting torus is cooled mainly by...
How rapidly do supermassive black hole "seeds" grow at early times? (2007)
Pelupessy, Federico I., Di Matteo, Tiziana, Ciardi, Benedetta
We investigate the physical conditions for the growth of intermediate mass seed black holes assumed to have formed from remnants of the first generation of massive stars. We follow the collapse of...
Angular Anisotropies in the Cosmic Gamma-ray Background as a Probe of its Origin (2007)
Miniati, Francesco, Koushiappas, Savvas M., Di Matteo, Tiziana
Notwithstanding the advent of the Gamma-ray Large Area Telescope, theoretical models predict that a significant fraction of the cosmic gamma-ray background (CGB), at the level of 20% of the currently...
Formation of z~6 quasars from hierarchical galaxy mergers (2007)
Li, Yuexing, Hernquist, Lars, Robertson, Brant, Cox, Thomas J., Hopkins, Philip F., Springel, Volker, ...
How rapidly do supermassive black hole 'seeds' grow at early times? (2007)
Pelupessy, Federico I., Di Matteo, Tiziana, Ciardi, Benedetta
A unified model for AGN feedback in cosmological simulations of structure formation (2007)
Sijacki, Debora, Springel, Volker, Di Matteo, Tiziana, Hernquist, Lars
Formation of z ~ 6 quasars from hierarchical galaxy mergers (2006)
Li, Yuexing, Hernquist, Lars, Robertson, Brant, Cox, Thomas J., Hopkins, Philip F., Springel, Volker, ...
The discovery of luminous quasars at redshift z ~ 6 indicates the presence of supermassive black holes (SMBHs) of mass ~10^9 Msun when the Universe was less than one billion years old. This finding...
Kinematic Structure of Merger Remnants (2006)
Cox, T. J., Dutta, Suvendra N., Di Matteo, Tiziana, Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, ...
We use numerical simulations to study the kinematic structure of remnants formed from mergers of equal-mass disk galaxies. In particular, we show that remnants of dissipational mergers, which include...
Chakrabarti, Sukanya, Cox, T. J., Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, Di Matteo, Tiziana
We calculate infrared spectral energy distributions (SEDs) from simulations of major galaxy mergers and study the effect of AGN and starburst driven feedback on the evolution of the SED as a function...
Molecular Outflows in Galaxy Merger Simulations with Embedded AGN (2006)
Narayanan, Desika, Cox, Thomas J., Robertson, Brant, Dave, Romeel, Di Matteo, Tiziana, Hernquist, Lars, ...
We study the effects of feedback from active galactic nuclei (AGN) on emission from molecular gas in galaxy mergers by combining hydrodynamic simulations which include black holes with a...
Simulated Molecular Gas Emission in Galaxy Mergers with Embedded AGN (2006)
Narayanan, Desika, Cox, Thomas J., Robertson, Brant, Dave, Romeel, Di Matteo, Tiziana, Hernquist, Lars, ...
We investigate the effect of embedded active galactic nuclei (AGN) in galaxy mergers on the CO molecular line emission by combining non-local thermodynamic equilibrium (LTE) radiative transfer...
Galactic centre stellar winds and Sgr A* accretion (2006)
Cuadra, Jorge, Nayakshin, Sergei, Springel, Volker, Di Matteo, Tiziana
The evolution in the faint-end slope of the quasar luminosity function (2006)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Robertson, Brant, Di Matteo, Tiziana, Springel, Volker
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
The evolution of the MBH-σ relation (2006)
Robertson, Brant, Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Hopkins, Philip F., Martini, Paul, ...
X-Ray emission from hot gas in galaxy mergers (2006)
Cox, T. J., Di Matteo, Tiziana, Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, Springel, Volker
A merger-driven scenario for cosmological disk galaxy formation (2006)
Robertson, Brant, Bullock, James S., Cox, Thomas J., Di Matteo, Tiziana, Hernquist, Lars, Springel, Volker, ...
The kinematic structure of merger remnants (2006)
Cox, T. J., Dutta, Suvendra N., Di Matteo, Tiziana, Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, ...
The Evolution in the Faint-End Slope of the Quasar Luminosity Function (2005)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
(Abridged) Based on numerical simulations of galaxy mergers that incorporate black hole (BH) growth, we predict the faint end slope of the quasar luminosity function (QLF) and its evolution with...
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
We present an evolutionary model for starbursts, quasars, and spheroidal galaxies in which mergers between gas-rich galaxies drive nuclear inflows of gas, producing intense starbursts and feeding the...
The Evolution of the M-sigma Relation (2005)
Robertson, Brant, Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Hopkins, Philip F., Martini, Paul, ...
(Abridged) We examine the evolution of the black hole mass - stellar velocity dispersion (M-sigma) relation over cosmic time using simulations of galaxy mergers that include feedback from...
Luminosity-Dependent Quasar Lifetimes: A New Interpretation of the Quasar Luminosity Function (2005)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
We propose a new interpretation of the quasar luminosity function (LF), derived from physically motivated models of quasar lifetimes and light curves. In our picture, quasars evolve rapidly and their...
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
We consider implications of our new model of quasar lifetimes and light curves for the quasar luminosity function (LF) at different frequencies and redshifts. In our picture, quasars evolve rapidly...
Black Holes in Galaxy Mergers: Evolution of Quasars (2005)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Martini, Paul, Robertson, Brant, ...
Based on numerical simulations of gas-rich galaxy mergers, we discuss a model in which quasar activity is tied to the self-regulated growth of supermassive black holes in galaxies. Nuclear inflow of...
X-ray Emission from Hot Gas in Galaxy Mergers (2005)
Cox, T. J., Di Matteo, Tiziana, Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, Springel, Volker
We examine X-ray emission produced from hot gas during collisions and mergers of disk galaxies. To study this process, we employ simulations that incorporate cosmologically motivated disk-galaxy...
A Merger-Driven Scenario for Cosmological Disk Galaxy Formation (2005)
Robertson, Brant, Bullock, James S., Cox, Thomas J., Di Matteo, Tiziana, Hernquist, Lars, Springel, Volker, ...
(Abridged) The violent hierarchical nature of the LCDM cosmology poses serious difficulties for the formation of disk galaxies. To help resolve these issues, we describe a new, merger-driven scenario...
A Physical Model for the Origin of Quasar Lifetimes (2005)
Hopkins, Philip F., Hernquist, Lars, Martini, Paul, Cox, Thomas J., Robertson, Brant, Di Matteo, Tiziana, ...
We propose a model of quasar lifetimes in which observational quasar lifetimes and an intrinsic lifetime of rapid accretion are strongly distinguished by the physics of obscuration by surrounding gas...
Di Matteo, Tiziana, Springel, Volker, Hernquist, Lars
In the early Universe, while galaxies were still forming, black holes as massive as a billion solar masses powered quasars. Supermassive black holes are found at the centers of most galaxies today,...
A physical model for the origin of quasar lifetimes (2005)
Hopkins, Philip F., Hernquist, Lars, Martini, Paul, Cox, Thomas J., Robertson, Brant, Di Matteo, Tiziana, ...
Black holes in galaxy mergers: evolution of quasars (2005)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Martini, Paul, Robertson, Brant, ...
Luminosity-dependent quasar lifetimes: a new interpretation of the quasar luminosity function (2005)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
On the relationship between the jets from X-ray binaries and Agn (2005)
Heinz, Sebastian, Merloni, Andrea, Di Matteo, Tiziana, Sunyaev, Rashid
Accretion of cool stellar winds on to Sgr A*: Another puzzle of the galactic centre? (2005)
Cuadra, Jorge, Nayakshin, Sergei, Springel, Volker, Di Matteo, Tiziana
Modeling feedback from stars and black holes in galaxy mergers (2004)
Springel, Volker, Di Matteo, Tiziana, Hernquist, Lars
We describe techniques for incorporating feedback from star formation and black hole accretion into simulations of isolated and merging galaxies. At present, the details of these processes cannot be...
A fundamental plane of black hole activity: pushing forward the unification scheme (2004)
Merloni, Andrea, Heinz, Sebastian, Di Matteo, Tiziana
We examine the disc--jet connection in stellar mass and supermassive black holes by investigating the properties of their compact emission in the hard X-ray and radio bands. We compile a sample of...
Black holes in galaxy mergers: The formation of red elliptical galaxies (2004)
Springel, Volker, Di Matteo, Tiziana, Hernquist, Lars
We use hydrodynamical simulations to study the color transformations induced by star formation and active galactic nuclei (AGN) during major mergers of spiral galaxies. Our modeling accounts for...
Tracing the cosmological assembly of stars and supermassive black holes in galaxies (2004)
Merloni, Andrea, Rudnick, Gregory, Di Matteo, Tiziana
We examine possible phenomenological constraints for the joint evolution of supermassive black holes (SMBH) and their host spheroids. We compare all the available observational data on the redshift...
Evolution of a neutrino-cooled disc in Gamma-Ray Bursts (2004)
Janiuk, Agnieszka, Perna, Rosalba, Di Matteo, Tiziana, Czerny, Bozena
Rapid, hyper-Eddington accretion is likely to power the central engines of gamma-ray bursts (GRBs). In the extreme conditions of densities and temperatures the accreting torus is cooled by neutrino...
The Clustering of AGN in the Sloan Digital Sky Survey (2004)
Wake, David A., Miller, Christopher J., Di Matteo, Tiziana, Nichol, Robert C., Pope, Adrian, Szalay, Alexander S., ...
We present the two--point correlation function (2PCF) of narrow-line active galactic nuclei (AGN) selected within the First Data Release of the Sloan Digital Sky Survey. Using a sample of 13605 AGN...
The 21 centimeter emission from the reionization epoch: extended and point source foregrounds (2004)
Di Matteo, Tiziana, Ciardi, Benedetta, Miniati, Francesco
Fluctuations in the redshifted 21 centimeter emission from neutral hydrogen probe the epoch of reionization. We examine the observability of this signal and the impact of extragalactic foreground...
The cosmological evolution of metal enrichment in quasar host galaxies (2004)
Di Matteo, Tiziana, Croft, Rupert A. C., Springel, Volker, Hernquist, Lars
The clustering of active galactic nuclei in the Sloan Digital Sky Survey (2004)
Wake, David A., Miller, Christopher J., Di Matteo, Tiziana, Nichol, Robert C., Pope, Adrian, Szalay, Alexander S., ...
The cosmological evolution of metal enrichment in quasar host galaxies (2003)
Di Matteo, Tiziana, Croft, Rupert A. C., Springel, Volker, Hernquist, Lars
We study the gas metallicity of quasar hosts using cosmological hydrodynamic simulations of the Lambda-cold dark matter model. Galaxy formation in the simulations is coupled with a prescription for...
A fundamental plane of black hole activity (2003)
Merloni, Andrea, Heinz, Sebastian, Di Matteo, Tiziana
We examine the disc--jet connection in stellar mass and supermassive black holes by investigating the properties of their compact emission in the X-ray and radio bands. We compile a sample of ~100...
Black hole growth and activity in a LambdaCDM Universe (2003)
Di Matteo, Tiziana, Croft, Rupert A. C., Springel, Volker, Hernquist, Lars
(abridged) The observed properties of supermassive black holes suggest a fundamental link between their assembly and the formation of their host spheroids. We model the growth and activity of black...
Low-luminosity black holes: The case of M87 (2003)
Di Matteo, Tiziana, Allen, Steven W., Fabian, Andrew C., Wilson, Andrew S., Young, Andrew J.
Neutrino trapping and accretion models for Gamma-Ray Bursts (2002)
Di Matteo, Tiziana, Perna, Rosalba, Narayan, Ramesh
Many models of Gamma Ray Bursts invoke a central engine consisting of a black hole of a few solar masses accreting matter from a disk at a rate of a fraction to a few solar masses per second. Popham...
Accretion onto the Supermassive Black Hole in M87 (2002)
Di Matteo, Tiziana, Allen, Steven W., Fabian, Andrew C., Wilson, Andrew S., Young, Andrew J.
Chandra X-ray observations of the giant elliptical galaxy M87 resolve the thermal state of the hot interstellar medium into the accretion (Bondi) radius of its central 3 10^9 Msun black hole. We...
Stress transmission in granular matter (2001)
Aste, Tomaso, Di Matteo, Tiziana, D'Agliano, Enrico Galleani
The transmission of forces through a disordered granular system is studied by means of a geometrical-topological approach that reduces the granular packing into a set of layers. This layered...
An empirical analysis of medium-term interest rates (2001)
Di Matteo, Tiziana, Scalas, Enrico, Airoldi, Marco
In the present paper, an empirical study of LIBOR (London Interbank Offered Rate) data is presented. In particular, a data set of interest rates from 1997 to 1999, for two different currencies and...
Di Matteo, Tiziana, Perna, Rosalba, Abel, Tom, Rees, Martin J.
Absorption or emission against the cosmic microwave background radiation (CMB) may be observed in the redshifted 21cm line if the spin temperature of the neutral intergalactic medium prior to...
How does the Eurodollar Interest Rate behave? (2001)
Di Matteo, Tiziana, Aste, Tomaso
An empirical analysis on Eurodollar interest rates daily data in the time period 1990-1996, is performed and compared with Libor data in the time period 1984-1998. The complementary cumulative...
Hydrodynamic Simulation of the Cosmological X-ray Background (2000)
Croft, Rupert A. C., Di Matteo, Tiziana, Dav'e, Romeel, Hernquist, Lars, Katz, Neal, Fardal, Mark A., ...
(Abridged) We use a hydrodynamic simulation of a LambdaCDM model to predict the extragalactic X-ray background (XRB), focussing on emission from the intergalactic medium (IGM). We also include X-rays...
Synchrotron Emission from Hot Accretion Flows and the Cosmic Microwave Background Anisotropy (2000)
Perna, Rosalba, Di Matteo, Tiziana
Current estimates of number counts of radio sources in the frequency range where the most sensitive Cosmic Microwave Background (CMB) experiments are carried out significantly under-represent sources...
X-ray Images of Hot Accretion Flows (2000)
Ozel, Feryal, Di Matteo, Tiziana
We consider the X-ray emission due to bremsstrahlung processes from hot, low radiative-efficiency accretion flows around supermassive and galactic black holes. We calculate surface brightness...
Hard X-ray emission from elliptical galaxies and its contribution to the X-ray background (1999)
Di Matteo, Tiziana, Allen, Steven W.
We explore the implications of the discovery of hard, power-law X-ray sources in the spectra of nearby elliptical galaxies for the origin of the X-ray background. The spectra of these sources are...
Di Matteo, Tiziana, Psaltis, Dimitrios
We calculate upper bounds on the inner radii of geometrically thin accretion disks in galactic black-hole systems by relating their rapid variability properties to those of neutron stars. We infer...
Quataert, Eliot, Di Matteo, Tiziana, Narayan, Ramesh, Ho, Luis C.
M81 and NGC 4579 are two of the few low-luminosity active galactic nuclei which have an estimated mass for the central black hole, detected hard X-ray emission, and detected optical/UV emission. In...
Wilms, Joern, Nowak, Michael, Dove, James B., Fender, Robert P., Di Matteo, Tiziana
We discuss a series of observations of the black hole candidate GX 339-4 in low luminosity, spectrally hard states. We present spectral analysis of three separate archival Advanced Satellite for...
Di Matteo, Tiziana, Celotti, Annalisa, Fabian, Andrew C.
We present a model for the different X-ray spectral states displayed by Galactic Black Hole Candidates (GBHC). We discuss the physical and spectral implications for a magnetically structured corona...
Liu, Ruipeng, Di Matteo, Tiziana, Lux, Thomas
In this paper, we consider daily financial data of a collection of different stock market indices, exchange rates, and interest rates, and we analyze their multi-scaling properties by estimating a...