Fabio De Colle's webpage

About

Astrophysicist

I am a researcher at the Instituto de Ciencias Nucleares at UNAM (in Mexico City), where I specialize in numerical simulations of high-energy astrophysical phenomena. My research focuses on understanding the behavior of jets and explosive events across various scales, including relativistic jets associated with gamma-ray bursts (GRBs), core-collapse supernovae, and tidal disruption events (TDEs). These phenomena represent some of the most energetic and dynamic processes in the universe. On the left, you can see a "word cloud" of all words included in the abstracts of my papers. "Jet", "GRB", "emission", "simulation", and "SN" are the most common words.

To explore these high-energy events, I develop advanced computational methods, such as adaptive mesh refinement (AMR) and moving mesh techniques. These methods allow me to simulate complex fluid dynamics, magnetic fields, and radiation processes in systems involving extreme conditions. I integrate hyperbolic equations, including hydrodynamics, magnetohydrodynamics (MHD), and their relativistic counterparts, to model the interactions between matter and radiation in these violent astrophysical environments. In recent years, I have incorporated machine learning and data science techniques into my research to improve both the analysis of simulation data and the modeling of astrophysical systems.

CV

Summary

Fabio De Colle

Numerical astrophysicist - Studying astrophysical flows, in particular jets at different scales (from HH to ultra-relativistic jets associated to gamma-ray bursts), supernovae and supernovae remnants. Developer of adaptive mesh refinement and moving mesh codes for the integration of hyperbolic equations.

Professional Experience

Researcher

2012 - Present

UNAM, Mexico

Numerical simulations of astrophysical flows, in particular high energy transients.
Investigador Asociado C from 2012, Titular A from 2016, Titular B from 2019, SNI II

Post-doctoral researcher

2009 - 2012

University of California at Santa Cruz, USA

Numerical simulations of relativistic jets associated to gamma-ray bursts and tidal disruption events

"Marie Curie" post-doctoral researcher

2006 - 2008

Dublin Institute for Advanced Studies, Ireland

Numerical simulations of protostellar, HH jets

Education

PhD in Astrophysics

2003 - 2005

UNAM, Mexico City, Mexico

Tesis on "Jets and disks around young stars", with honours

Master in Astrophysics

2001 - 2003

UNAM, Mexico City, Mexico

"Laurea" in physics

1993 - 1999

Universita' dell'Insubria, Como, Italia

Tesis on "Diagnostics and modelization of an SF₆ plasma for industrial applications", with honours (110/110 cum laude)

Research

I study high-energy astrophysical transients, focusing on the physics of relativistic jets in gamma-ray bursts (GRBs), tidal disruption events (TDEs), and supernovae (SNe). My work includes numerical simulations of GRB afterglows, polarization studies, and jet structure modeling, particularly in off-axis and structured jet scenarios. I have explored jet interactions in diverse environments, including common envelope (CE) evolution, supernova remnants, and neutron star mergers, with implications for gravitational wave (GW) sources. I have developed "Mezcal", a high-performance astrophysical simulation code using adaptive mesh refinement (AMR) and running on supercomputers (the code employs the MPI library). The code currently integrates hydrodynamics (HD), magnetohydrodynamics (MHD), and special relativistic hydrodynamics (SRHD) equations. I am extending it to include special relativistic MHD (SRMHD) and radiation in all four cases while optimizing it for parallel execution using OpenMP and GPUs. My research employs advanced computational methods, machine learning techniques for GRB classification, and multi-wavelength observational data analysis to understand the dynamics and emission properties of transient astrophysical phenomena.

Working On

Currently, I am working on a variety of topics, including: code developement (see more information in the link below); numerical simulations of planet-stellar magnetosphere interaction; numerical simulations of shock wave propagation in laboratory; radio emission from supernovae (using a new machine learning approach); numerical simulations of TDE jets; and numerical simulations of GRB cocoon and off-axis emission. In addition. For recent results, click the "Learn More" button below.

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Gamma-ray Bursts (GRBs)

GRBs are high-energy explosions associated with relativistic jets ejected during the collapse of massive stars or during star mergers. My research focuses on understanding the dynamics and emission properties of GRB jets, including the effects of jet structure, viewing angles, and late-time energy injection. I also explore the interaction of GRB jets with their environment, using numerical simulations to model their afterglows and polarization, providing insights into the physical conditions and evolution of these extreme cosmic events.

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Herbig-Haro Jets and star formation

Herbig-Haro, or HH jets, are collimated outflows of gas produced by young, forming stars. My research on Herbig-Haro jets focuses on the dynamics and evolution of these outflows, investigating their interaction with the surrounding medium. I utilize simulations to explore their emission features, their velocity structures, and the role played by magnetic fields in determining their dynamical evolution.

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Tidal Disruption Events (TDEs)

TDEs are catastrophic events where a star is torn apart by the tidal forces of a supermassive black hole. My research on TDEs involves exploring the dynamics of accretion and jet formation during these events, as well as the subsequent emission signatures across various wavelengths. I focus on understanding how TDEs can produce high-energy radiation and the role of relativistic jets, using simulations to study the impact of these events on their surrounding environments.

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Jets in Common Envelope Phase (CE)

Jets formed during the common envelope phase, which occurs when a primary star expands into a giant and engulfes its companion star, which then spirals inward. These jets are a crucial phenomenon in determining the evolution of binary stars. My research focuses on the dynamics and evolution of jets in this phase, particularly in systems leading to compact binary mergers (e.g., systems in which the companion star is either a neutron star of a black hole).

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Supernovae (SNe)

SNe are explosive events associated to the death of massive stars. SNe explosions lead to the formation of neutron stars or black holes. My research on SNe focuses on understanding their complex interaction histories, such as supernovae interacting with dense circumstellar material, and their relation with GRBs.

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Numerical Codes Development

I have developed my own code, MEZCAL, which uses Adaptive Mesh Refinement (AMR) to solve hydrodynamics (HD), magnetohydrodynamics (MHD), and special relativistic hydrodynamics (SRHD) equations. The code is optimized to run on supercomputers using MPI and is currently being extended to include special relativistic MHD (SRMHD) and radiation physics for all the mentioned configurations. I am also currently parallelizing the code using OpenMP and GPU acceleration to improve computational efficiency, exploring moving mesh methods and more complex mesh structures (based on Delauney and Voronoi tessellations).

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Students/Postdocs

Please contact me if you are interested in a PhD, master's or bachelor's degree project. Possible projects include numerical simulations of astrophysical transients, relativistic jets associated with black holes and neutron stars, supernovae, radiation processes, common envelope evolution, and other astrophysical flows, machine learning applied to astrophysical data, and code development (hydrodynamics, radiation transfer, etc.).

Current Students:

Jesus Carrillo - PhD thesis (astrophysics, UNAM) on "Common Envelopes" - in process - co-supervisor Diego Lopez Camara.
Jhonnayker Paredes - Master's thesis (astrophysics, UNAM) on "Dinamica y emision de particulas no-termicas" - in process.
Lizeth Meza - Bachelor's thesis (physics, UNAM) on "Emision en radio de supernovas" - in process.
Carla Chavez - Bachelor's thesis (matheamtics, UNAM)) on "Paralelizacion de codigos hidrodinamicos por medios de teoria de grafos" - in process.

Postdoc:

Rosa Becerra - Postdoc - Working on observations of GRBs by robotic telescopes (2020-2023)

PhD Students:

Rogelio Medina - PhD thesis (astrophysics, UNAM) on "Polarization in gamma-ray bursts" (2024).
Felipe Vargas - PhD thesis (astrophysics, UNAM) on "Modeling strongly interacting supernovae" (2023).
Gerardo Urrutia - PhD thesis (astrophysics, UNAM) on "Numerical simulations of structured Short/Long GRBs and their off-axis emission" (2023)

Master's students:

Keneth Garcia - Master's thesis (astrophysics, UNAM) on "Identification of extended emission gamma-ray burst candidates using machine learning" (2024) - co-supervisor Rosa Becerra.
Ana Juarez - Master thesis (astrophysics, UNAM) on "Simulaciones numéricas de destellos de rayos gamma en un sistema de referencia en movimiento" (2021).
Ana Paola Hernandez - Master's thesis (astrophysics, UNAM) on "Espectro de sincrotrón proveniente de GRBs" (2020).
Felipe Vargas - Master thesis (astrophysics, University of Rio Grande, Brasil) on "Supernova y una cáscara de nuez: un estudio de la transición de la SN 2014c de tipo I a tipo II" (2019) - co-supervisor Giovanny Bernal
Gerardo Urrutia - Master's thesis on "La estructura angular de los destellos de rayos gamma" (2018).
Alejandra Jiménez - Master's thesis on "Simulaciones numéricas de variabilidad en la emisión de GRBs" (2016).