Postdoctoral position on the study of galaxy evolution based on deep optical imaging

The post-doc will work on the identification of fine structures (collisional debris) on ultra deep images of a large sample of nearby massive galaxies, with methods combining eye detection and a deep learning approach. He will then compare the statistical results with predictions from cosmological simulations, with the aim of reconstructing the past mass assembly of the galaxies in the sample.

Context

The low surface brightness (LSB) Universe is still largely unexplored and underexploited, despite the fact that it contains a wealth of information on galaxy structuration as well as on the structure of the interstellar medium within galaxies. The post-doc will be involved in an in-depth exploration of this regime, based on a unique set of deep optical images obtained with three Large Programmes obtained at CFHT: NGVS, MATLAS and CFIS. This international project focuses on three main topics:

• Understanding the structuration of galaxies with LSB stellar structures
• Understanding the structure of the interstellar medium with the diffuse galactic light
• Optimizing the data processing and investigating the capabilities of new surveys to further explore the LSB Universe

Tasks

The post-doc will mainly focus his work on the first task. Immediate aims are to make a census of the collisional debris (shells, tails, streams) of an initial sample of about 1000 massive galaxies in the Nearby Universe. Annotation tools have already been developed to help with this task. The collected database will enable the training of deep learning algorithms that will be used to characterize the outskirts of a larger sample of galaxies from the CFIS survey.

Besides, this census will be compared to predictions from cosmological numerical simulations so as to get constrains on the past mass assembly of the galaxies, depending on their mass, type and environment.

Location

The position is located at the University of Strasbourg / Observatoire astronomique de Strasbourg (France). The post-doc will work under the supervision of Dr. Pierre-Alain Duc. He/she will be a member of the GALHECOS team (group leader: B. Famaey), which has a strong expertise in Galaxy archeology.

The candidate should work in the field of galaxy evolution, and have an expertise on deep optical imaging and/or numerical simulations of galaxy collisions.