Theory Group Concepción

Departamento de Astronomía, Universidad de Concepción, Chile

Subgroup Prof. Dominik Schleicher

Formation of the first stars in the Universe:
including primordial and metal poor stars. Our goal is to understand the role of chemistry and cooling during the fragmentation process, and the typical stellar mass as a function of metallicity.
project page
In our new project we are working on the formation of the very first star clusters in the Universe.
Formation of the first supermassive black holes:
with a particular focus on the direct collapse scenario. We explore the circumstances that can lead to the direct collapse of a massive gas cloud with no or very little fragmentation. A particular focus concerns the role of the ambient radiation background as well as the viscous heating in self-gravitating disks.
project page
Modeling astrochemistry in 3D simulations:
Chemistry and cooling play a central role in many astrophysical applications, and there modeling is therefore important to understand fragmentation and the stability of self-gravitating disks. We are therefore participating in the development of the astrochemistry package KROME to include chemistry in 3D simulations.
project page
The origin of magnetic fields:
Magnetic fields are ubiquitos in the Universe, and the observed synchrotron fluxes from high redshift galaxies suggest their formation at early times in the Universe. We explore in particular the role of the small-scale dynamo for the amplification of magnetic fields, and how it contributes to establish the far-infrared - radio correlation.
project page
The importance of magnetic fields in star formation:
We investigate the role of magnetic fields in nearby massive star forming regions.
Variability in Close Binary Systems:
We are interested in the modeling of hydrodynamical and magneto-hydrodynamical processes in compact binary systems. The latter includes the formation of accretion disks due to Roche lobe overflow or stellar winds, as well as dynamo action due to the rapid rotation in compact binaries. Such processes may give rise to the observed eclipsing time variations in Post-Common-Envelope Binaries (PCEBs) and potentially explain the long period in Double Periodic Variables (DPVs). We also explore whether the observed eclipsing time variations of the PCEBs can be interpreted as planets.
project page
Accretion physics in Active Galactic Nuclei:
Black hole accretion in Active Galactic Nuclei (AGN) provides an important test for the physics of accretion disks, which may be regulated by self-gravitating instabilities and magneto-hydrodynamical instabilities. We are both interested in the regime of strong active accretion, which is responsible for the formation of supermassive black holes, as well as accretion of nearby AGN at low Eddington ratios, which can be probed via the Event Horizon Telescope (EHT, http://www.eventhorizontelescope.org/). Important science question concern both the physics governing the transition from the low-luminosity to the high-luminosity regime, as well as the origin of viscosity in the accretion disks.
© Theory Group Concepcion 2021