Tiziana Di Matteo's research focuses on the study 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.
Areas of Expertise (5)
High Energy Astrophysics
Media Appearances (5)
Hubble Finds Double Quasar in Early Universe
Carnegie Mellon University News online
“Understanding how black holes form, the first quasars emerge and how they grow along our cosmic histories is one of the greatest theoretical and observational challenges of modern astrophysics,” said Tiziana Di Matteo(opens in new window), professor of physics and director of Carnegie Mellon’s McWilliams Center for Cosmology(opens in new window).
Machine learning accelerates cosmological simulations
Carnegie Mellon University Physics Professors Tiziana Di Matteo and Rupert Croft, Flatiron Institute Research Fellow Yin Li, Carnegie Mellon Ph.D. candidate Yueying Ni, University of California Riverside Professor of Physics and Astronomy Simeon Bird and University of California Berkeley's Yu Feng surmounted this problem by teaching a machine learning algorithm based on neural networks to upgrade a simulation from low resolution to super resolution.
A taste of James Webb’s potential
To determine what Webb is expected to see, the team then used a state-of-the-art computer simulation called BlueTides, developed by a team led by Tiziana Di Matteo from Carnegie Mellon University (CMU) in Pittsburgh, US.
Milky Way-like galaxies may have existed in the early universe
"It's awe inspiring to think that galaxies much like our own existed when the universe was so young," said Tiziana Di Matteo, professor of physics at Carnegie Mellon. "The deepest Hubble Space Telescope observations have thus only covered small volumes of space and have found very irregular, clumpy galaxies at these early epochs. It is not surprising that in these small volumes some of the small galaxies do not have regular morphologies like large disk galaxies. Similarly, numerical simulations have been limited in size so they have only made predictions for the smaller, clumpier galaxies at these early times."
Simulation showing Milky Way-esque galaxy in early universe could prove cold dark matter theory
Tiziana Di Matteo, professor of physics at Carnegie Mellon, said: "It's awe inspiring to think that galaxies much like our own existed when the universe was so young. The deepest Hubble Space Telescope observations have thus far only covered small volumes of space and have found very irregular, clumpy galaxies at these early epochs.
Industry Expertise (2)
Royal Astronomical Society Michael Penston Prize (professional)
Carnegie Science Award of Excellence (professional)
University College London: B.Sc., Astrophysics 1995
University of Cambridge: Ph.D., Astrophysics 1998
- American Physical Society : Fellow
- LSST Dark Energy Sciente Collaboration, Cosmological Simulation Task Force : Member
- NSF XSEDE Resource Allocation Committee : Member
- Carnegie Science Center Awards of Excellence Committee : Member
Overmassive central black holes in the cosmological simulations ASTRID and Illustris TNG50Monthly Notices of the Royal Astronomical Society
2023 Recent dynamical measurements indicate the presence of a central supermassive black hole (SMBH) with mass ∼3×106M⊙ in the dwarf galaxy Leo I, placing the system ∼50 times above the standard, local MBH–M⋆ relation. While a few overmassive central SMBHs are reported in nearby isolated galaxies, this is the first one detected in a Milky Way satellite.
Statistics of Galactic-scale Quasar Pairs at Cosmic NoonThe Astrophysical Journal
2023 The statistics of galactic-scale quasar pairs can elucidate our understanding of the dynamical evolution of supermassive black hole (SMBH) pairs, the duty cycles of quasar activity in mergers, or even the nature of dark matter, but they have been challenging to measure at cosmic noon, the prime epoch of massive galaxy and SMBH formation. Here we measure a double quasar fraction of ∼6.2 ± 0.5 × 10−4 integrated over ∼0farcs3–3'' separations (projected physical separations of ∼3–30 kpc at z ∼ 2) in luminous (Lbol > 1045.8 erg s−1) unobscured quasars at 1.5 < z < 3.5 using Gaia EDR3-resolved pairs around SDSS DR16 quasars.
Unveiling the first seeds of supermassive black holes using cosmological simulationsBulletin of the American Physical Society
2022 Supermassive black holes are now believed to be at the centers of almost every massive galaxy in our Universe. Where and how did they form and grow to their observed masses (a million to tens of billion solar masses)? Unveiling the nature of their first "seeds" is a key science goal for current and future observational facilities such as JWST, LISA and Lynx. Predictions from cosmological hydrodynamic simulations are going to be crucial for using data from upcoming facilities to determine seeding mechanisms.
Orbital and radiative properties of wandering intermediate-mass black holes in the ASTRID simulationMonthly Notices of the Royal Astronomical Society
2023 Intermediate-Mass Black Holes (IMBHs) of 103−106M⊙ are commonly found at the centre of dwarf galaxies. Simulations and observations convincingly show that a sizeable population of IMBHs could wander off-centre in galaxies. We use the cosmological simulation ASTRID to study the orbital and radiative properties of wandering IMBHs in massive galaxies at z ∼ 3.
Concordance between Observations and Simulations in the Evolution of the Mass Relation between Supermassive Black Holes and Their Host GalaxiesThe Astrophysical Journal
2022 We carry out a comparative analysis of the relation between the mass of supermassive black holes (BHs) and the stellar mass of their host galaxies at 0.2 < z < 1.7 using well-matched observations and multiple state-of-the-art simulations (e.g., MassiveBlackII, Horizon-AGN, Illustris, TNG, and a semianalytic model). The observed sample consists of 646 uniformly selected Sloan Digital Sky Survey quasars (0.2 < z < 0.8) and 32 broad-line active galactic nuclei (AGNs; 1.2 < z < 1.7) with imaging from Hyper Suprime-Cam (HSC) for the former and Hubble Space Telescope (HST) for the latter.