Offre en lien avec l’Action/le Réseau : – — –/Doctorants

Laboratoire/Entreprise : LPC2E/CNRS
Durée : 4-6 mois
Contact : cherry.ng-guiheneuf@cnrs-orleans.fr
Date limite de publication : 2026-12-31

Contexte :
Pulsars are highly magnetized, rapidly rotating neutron stars that provide unique laboratories for studying fundamental physics, compact objects and the interstellar medium. Their periodic radio emission makes them well suited to large-scale surveys, while individual pulses provide insights into the physics of coherent radio emission. Despite decades of observations, a significant fraction of the Galactic pulsar population remains undiscovered, motivating the development of efficient analysis techniques.

Sujet :
During this internship, the trainee will get an opportunity to gain experience in two complementary areas of pulsar research: pulsar survey analysis with machine-learning-assisted candidate classification, and the study of individual pulsar pulses across widely separated radio frequencies.

The first part will involve a complete pulsar-search workflow, from simulations and population modelling to candidate generation and classification. The trainee will use tools such as PsrPopPy to generate synthetic pulsar populations, exploring distributions of periods, dispersion measures, luminosities and spatial positions. Synthetic pulsars will be injected into real survey data and processed through an existing search pipeline to evaluate recovery rates and characterize detection efficiency. The resulting candidates will be visually inspected to build a labelled dataset for exploring machine-learning methods to distinguish genuine pulsars from radio-frequency interference and other false positives, with the goal of improving candidate classification for large surveys.

The second part will focus on single-pulse emission from a pulsar observed at approximately 70 MHz and 1.4 GHz. Using an existing pipeline, the trainee will extract individual pulses, characterize their energy distributions statistically, and investigate possible log-normal or power-law behaviour and frequency-dependent changes. The results will be interpreted in the context of nulling, mode changing and giant pulses, with comparisons to Fast Radio Bursts where appropriate.

The internship will provide hands-on experience in radio astronomy, pulsar searches, population synthesis, statistical analysis, machine learning, Python-based scientific computing and the analysis of real observational data. The trainee will also have the opportunity to visit the Nançay Radio Observatory, participate in collaboration meetings and present their work to the wider pulsar research community.

Profil du candidat :
Master en astronomie, informatique ou domaine similaire

Formation et compétences requises :
programmation python
Programmation linux

Adresse d’emploi :
3A, Avenue de la Recherche Scientifique. 45071 Orléans cedex 2. France