I'm a post-doctoral fellow at the Theoretical Astrophysics Group group at Köln University.

I'm interested in studying the physical processes in the interstellar medium. For purpose I perform three-dimensional Magnetohydrodynamics numerical simulations of the interstellar medium in a Galaxy.

About me

I am a Colombian physicist, I obtained my PhD working in a collaboration between Heidelberg University and the American Museum of Natural History in New York, where I studied how molecular clouds acquire their properties and how they interact with their turbulent environments.
I did my Bachelor in Physics at the Universidad Nacional de Colombia, then I moved to Germany to do a Master in Astrophysics at the Argelander Institut fuer Astronomie (AIfA).


I am a theoretical astrophysicist, studying the formation and dynamics of astrophysical systems with the aid of numerical simulations. I am interested in the physical properties and the dynamical evolution of the interstellar medium (ISM) in galaxies. How dense molecular clouds are formed in the galaxy and their subsequent evolution and collapse. I am also very interested in trying to understand the influence of magnetic fields at various stages of star formation and evolution. How these magnetic fields affect the dynamics of dense clouds, their influence in the rotation rates of pre-main sequence stars and how they affect the life of fast rotating massive stars.

Beyond Astrophysics, I am also interested developing open source software for data analysis. Right now we have developed Concordia_draw, a python based software to analyze large datasets of U-Pb mass spectrometry for applications in geochronology.

Animations and extra material from my papers:
Accretion-driven turbulence in hierarchically collapsing clouds
Origin of the velocity dispersion-size relation in molecular clouds

Download my theses

PhD thesis, Institut für Theoretische Astrophysik, Heidelberg University, July 2016:

Formation and Evolution of Molecular Clouds in a Turbulent Interstellar Medium.

Master thesis, Argelander-Institut für Astronomie, Bonn University, September 2012:

Magnetohydrodynamic Instabilities in Stellar Radiative Zones.

Bachelor thesis, Observatorio Astrónomico Nacional, Universidad Nacional de Colombia, July 2010:

Spin Evolution of a Young Solar Type Star.


This is a list of my most recent publications

Accepted for Publication in ApJ. Juan C. Ibáñez-Mejía, Mordecai-Mark Mac Low, Ralf S. Klessen and Christian Bazcynski. Accretion-driven turbulence in hierarchically-contracting molecular clouds.

2017 ApJ. Mac Low, Mordecai-Mark; Burkert, Andreas; Ibáñez-Mejía, Juan C. Fast Molecular Cloud Destruction Requires Fast Cloud Formation

2016 ApJ. Juan C. Ibáñez-Mejía, Mordecai-Mark Mac Low, Ralf S. Klessen and Christian Bazcynski. Gravitational contraction versus supernova driving and the origin of the velocity dispersion-size relation in molecular clouds.

click HERE for a full list.


if you want to contact me, please write me an email to jcibanezmejia at gmail.com